0024336: Content of OCCT documentation should be updated. Iter 2

[occt.git] / dox / user_guides / draw_test_harness.md

Draw Test Harness  {#user_guides__test_harness}
===============================

@tableofcontents
 
@section occt_draw_1 Introduction

This manual explains how to use Draw, the test harness for Open CASCADE Technology (**OCCT**). It provides basic documentation on using Draw. For advanced information on Draw and its applications, see our offerings on our web site at <a href="http://www.opencascade.org/support/training">http://www.opencascade.org/support/training</a>  

Draw is a command interpreter based on TCL and a graphical system used to test and demonstrate Open CASCADE Technology modeling libraries. 


@subsection occt_draw_1_1 Overview

Draw is a test harness for Open CASCADE Technology. It provides a flexible and easy to use means of testing and demonstrating the OCCT modeling libraries. 

Draw can be used interactively to create, display and modify objects such as curves, surfaces and topological shapes. 

Scripts may be written to customize Draw and perform tests. New types of objects and new commands may be added using the C++ programing language. 

Draw consists of: 

  * A command interpreter based on the TCL command language.
  * A 3d graphic viewer based on the X system.
  * A basic set of commands covering scripts, variables and graphics.
  * A set of geometric commands allowing the user to create and modify curves and surfaces and to use OCCT geometry algorithms. This set of commands is optional.
  * A set of topological commands allowing the user to create and modify BRep shapes and to use the OCCT topology algorithms.


There is also a set of commands for each delivery unit in the modeling libraries: 

  * GEOMETRY, 
  * TOPOLOGY, 
  * ADVALGOS, 
  * GRAPHIC, 
  * PRESENTATION. 


@subsection occt_draw_1_2 Contents of this documentation

This documentation describes: 

  * The command language.
  * The basic set of commands.
  * The graphical commands.
  * The Geometry set of commands.
  * The Topology set of commands.

This document does not describe other sets of commands and does not explain how to extend Draw using C++. 

This document is a reference manual. It contains a full description of each command. All descriptions have the format illustrated below for the exit command. 

~~~~~
exit
~~~~~

Terminates the Draw, TCL session. If the commands are read from a file using the source command, this will terminate the file. 

**Example:** 

~~~~~
# this is a very short example 
exit 
~~~~~


@subsection occt_draw_1_3 Getting started

Install Draw and launch Emacs. Get a command line in Emacs using *Esc x *and key in *woksh*. 

All DRAW Test Harness can be activated in the common executable called **DRAWEXE**. They are grouped in toolkits and can be loaded at run-time thereby implementing dynamically loaded plug-ins. Thus, it is possible to work only with the required commands adding them dynamically without leaving the Test Harness session. 

Declaration of available plug-ins is done through the special resource file(s). The *pload* command loads the plug-in in accordance with the specified resource file and activates the commands implemented in the plug-in. 

@subsubsection occt_draw_1_3_1 Launching DRAW Test Harness

Test Harness executable *DRAWEXE* is located in the <i>$CASROOT/<platform>/bin</i> directory (where <platform> is Win for Windows and Linux for Linux operating systems). Prior to launching it is important to make sure that the environment is correctly set-up (usually this is done automatically after the installation process on Windows or after launching specific scripts on Linux).  


@subsubsection occt_draw_1_3_2 Plug-in resource file

Open CASCADE Technology is shipped with the DrawPlugin resource file located in the <i>$CASROOT/src/DrawResources</i> directory. 

The format of the file is compliant with standard Open CASCADE Technology resource files (see the *Resource_Manager.cdl* file for details). 

Each key defines a sequence of either further (nested) keys or a name of the dynamic library. Keys can be nested down to an arbitrary level. However, cyclic dependencies between the keys are not checked. 

**Example:** (excerpt from DrawPlugin): 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
OCAF               : VISUALIZATION, OCAFKERNEL 
VISUALIZATION      : AISV 
OCAFKERNEL         : DCAF 

DCAF               : TKDCAF 
AISV               : TKViewerTest 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_1_3_3 Activation of commands implemented in the plug-in

To load a plug-in declared in the resource file and to activate the commands the following command must be used in Test Harness: 

~~~~~
pload [-PluginFileName] [[Key1] [Key2]...]
~~~~~

where: 

* <i>-PluginFileName</i> - defines the name of a plug-in resource file (prefix "-" is mandatory) described above. If this parameter is omitted then the default name *DrawPlugin* is used. 
* *Key…* - defines the key(s) enumerating plug-ins to be loaded. If no keys are specified then the key named *DEFAULT* is used (if there is no such key in the file then no plug-ins are loaded). 

According to the OCCT resource file management rules, to access the resource file the environment variable *CSF_PluginFileNameDefaults* (and optionally *CSF_PluginFileNameUserDefaults*) must be set and point to the directory storing the resource file. If it is omitted then the plug-in resource file will be searched in the <i>$CASROOT/src/DrawResources</i> directory. 

~~~~~
Draw[]        pload -DrawPlugin OCAF 
~~~~~
This command will search the resource file *DrawPlugin* using variable *CSF_DrawPluginDefaults* (and *CSF_DrawPluginUserDefaults*) and will start with the OCAF key. Since the *DrawPlugin* is the file shipped with Open CASCADE Technology it will be found in the <i>$CASROOT/src/DrawResources</i> directory (unless this location is redefined by user's variables). The OCAF key will be recursively extracted into two toolkits/plug-ins: *TKDCAF* and *TKViewerTest* (e.g. on Windows they correspond to *TKDCAF.dll* and *TKViewerTest.dll*). Thus, commands implemented for Visualization and OCAF will be loaded and activated in Test Harness. 

~~~~~
Draw[]        pload (equivalent to pload -DrawPlugin DEFAULT). 
~~~~~
This command will find the default DrawPlugin file and the DEFAULT key. The latter finally maps to the TKTopTest toolkit which implements basic modeling commands. 


@section occt_draw_2 The Command Language

@subsection occt_draw_2_1 Overview

The command language used in Draw is Tcl. Tcl documentation such as "TCL and the TK Toolkit" by John K. Ousterhout (Addison-Wesley) will prove useful if you intend to use Draw extensively. 

This chapter is designed to give you a short outline of both the TCL language and some extensions included in Draw. The following topics are covered: 

  * Syntax of the TCL language.
  * Accessing variables in TCL and Draw.
  * Control structures.
  * Procedures.

@subsection occt_draw_2_2 Syntax of TCL

TCL is an interpreted command language, not a structured language like C, Pascal, LISP or Basic. It uses a shell similar to that of csh. TCL is, however, easier to use than csh because control structures and procedures are easier to define. As well, because TCL does not assign a process to each command, it is faster than csh. 

The basic program for TCL is a script. A script consists of one or more commands. Commands are separated by new lines or semicolons. 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
set a 24 
set b 15 
set a 25; set b 15 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Each command consists of one or more *words*; the first word is the name of a command and additional words are arguments to that command. 

Words are separated by spaces or tabs. In the preceding example each of the four commands has three words. A command may contain any number of words and each word is a string of arbitrary length. 

The evaluation of a command by TCL is done in two steps. In the first step, the command is parsed and broken into words. Some substitutions are also performed. In the second step, the command procedure corresponding to the first word is called and the other words are interpreted as arguments. In the first step, there is only string manipulation, The words only acquire *meaning* in the second step by the command procedure. 

The following substitutions are performed by TCL: 

Variable substitution is triggered by the $ character (as with csh), the content of the variable is substitued; { } may be used as in csh to enclose the name of the variable. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# set a variable value 
set file documentation 
puts $file #to display file contents on the screen 

# a simple substitution, set psfile to documentation.ps 
set psfile $file.ps 
puts $psfile 

# another substitution, set pfile to documentationPS 
set pfile ${file}PS 

# a last one, 
# delete files NEWdocumentation and OLDdocumentation 
foreach prefix {NEW OLD} {rm $prefix$file} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Command substitution is triggered by the [ ] characters. The brackets must enclose a valid script. The script is evaluated and the result is substituted. 

Compare command construction in csh. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
set degree 30 
set pi 3.14159265 
# expr is a command evaluating a numeric expression 
set radian [expr $pi*$degree/180] 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Backslash substitution is triggered by the backslash character. It is used to insert special characters like $, [ , ] , etc. It is also useful to insert a new line, a backslash terminated line is continued on the following line. 

TCL uses two forms of *quoting* to prevent substitution and word breaking. 

Double quote *quoting* enables the definition of a string with space and tabs as a single word. Substitutions are still performed inside the inverted commas " ". 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# set msg to ;the price is 12.00; 
set price 12.00 
set msg ;the price is $price; 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Braces *quoting* prevents all substitutions. Braces are also nested. The main use of braces is to defer evaluation when defining procedures and control structures. Braces are used for a clearer presentation of TCL scripts on several lines. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
set x 0 
# this will loop for ever 
# because while argument is ;0  3; 
while ;$x  3; {set x [expr $x+1]} 
# this will terminate as expected because 
# while argument is {$x  3} 
while {$x  3} {set x [expr $x+1]} 
# this can be written also 
while {$x  3} { 
set x [expr $x+1] 
} 
# the following cannot be written 
# because while requires two arguments 
while {$x  3} 
{ 
set x [expr $x+1] 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Comments start with a \# character as the first non-blank character in a command. To add a comment at the end of the line, the comment must be preceded by a semi-colon to end the preceding command. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# This is a comment 
set a 1 # this is not a comment 
set b 1; # this is a comment 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The number of words is never changed by substitution when parsing in TCL. For example, the result of a substitution is always a single word. This is different from csh but convenient as the behavior of the parser is more predictable. It may sometimes be necessary to force a second round of parsing. **eval** accomplishes this: it accepts several arguments, concatenates them and executes the resulting script. 


**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# I want to delete two files 

set files ;foo bar; 

# this will fail because rm will receive only one argument 
# and complain that ;foo bar; does not exit 

exec rm $files 

# a second evaluation will do it 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsection occt_draw_2_3 Accessing variables in TCL and Draw

TCL variables have only string values. Note that even numeric values are stored as string literals, and computations using the **expr** command start by parsing the strings. Draw, however, requires variables with other kinds of values such as curves, surfaces or topological shapes. 

TCL provides a mechanism to link user data to variables. Using this functionality, Draw defines its variables as TCL variables with associated data. 

The string value of a Draw variable is meaningless. It is usually set to the name of the variable itself. Consequently, preceding a Draw variable with a <i>$</i> does not change the result of a command. The content of a Draw variable is accessed using appropriate commands. 

There are many kinds of Draw variables, and new ones may be added with C++. Geometric and topological variables are described below. 

Draw numeric variables can be used within an expression anywhere a Draw command requires a numeric value. The *expr* command is useless in this case as the variables are stored not as strings but as floating point values. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# dset is used for numeric variables 
# pi is a predefined Draw variable 
dset angle pi/3 radius 10 
point p radius*cos(angle) radius*sin(angle) 0 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It is recommended that you use TCL variables only for strings and Draw for numerals. That way, you will avoid the *expr* command. As a rule, Geometry and Topology require numbers but no strings. 

@subsubsection occt_draw_2_3_1 set, unset

Syntax:                  

~~~~~
set varname [value] 
unset varname [varname varname ...] 
~~~~~

*set* assigns a string value to a variable. If the variable does not already exist, it is created. 

Without a value, *set* returns the content of the variable. 

*unset* deletes variables. It is is also used to delete Draw variables. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
set a "Hello world"
set b "Goodbye" 
set a 
== "Hello world" 
unset a b 
set a 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Note**, that the *set* command can set only one variable, unlike the *dset* command. 


@subsubsection occt_draw_2_3_2 dset, dval

Syntax

~~~~~
dset var1 value1 vr2 value2 ... 
dval name 
~~~~~

*dset* assigns values to Draw numeric variables. The argument can be any numeric expression including Draw numeric variables. Since all Draw commands expect a numeric expression, there is no need to use $ or *expr*. The *dset* command can assign several variables. If there is an odd number of arguments, the last variable will be assigned a value of 0. If the variable does not exist, it will be created. 

*dval* evaluates an expression containing Draw numeric variables and returns the result as a string, even in the case of a single variable. This is not used in Draw commands as these usually interpret the expression. It is used for basic TCL commands expecting strings. 


**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# z is set to 0 
dset x 10 y 15 z 
== 0 

# no $ required for Draw commands 
point p x y z 

# *puts* prints a string 
puts ;x = [dval x], cos(x/pi) = [dval cos(x/pi)]; 
== x = 10, cos(x/pi) = -0.99913874099467914 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Note,** that in TCL, parentheses are not considered to be special characters. Do not forget to quote an expression if it contains spaces in order to avoid parsing different words. <i>(a + b)</i> is parsed as three words: <i>"(a + b)"</i> or <i>(a+b)</i> are correct.* 


@subsection occt_draw_2_4 lists

TCL uses lists. A list is a string containing elements separated by spaces or tabs. If the string contains braces, the braced part accounts as one element. 

This allows you to insert lists within lists. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# a list of 3 strings 
;a b c; 

# a list of two strings the first is a list of 2 
;{a b} c; 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Many TCL commands return lists and **foreach** is a useful way to create loops on list elements. 

@subsubsection occt_draw_2_5 Control Structures

TCL allows looping using control structures. The control structures are implemented by commands and their syntax is very similar to that of their C counterparts (**if**, **while**, **switch**, etc.). In this case, there are two main differences between TCL and C: 

* You use braces instead of parentheses to enclose conditions. 
* You do not start the script on the next line of your command. 


@subsubsection occt_draw_2_5_1 if

Syntax       

~~~~~
if condition script [elseif script .... else script] 
~~~~~

**If** evaluates the condition and the script to see whether the condition is true. 



**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
if {$x  0} { 
puts ;positive; 
} elseif {$x == 0} { 
puts ;null; 
} else { 
puts ;negative; 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_2_5_2 while, for, foreach

Syntax:                  


~~~~~~
while condition script 
for init condition reinit script 
foreach varname list script 
~~~~~

The three loop structures are similar to their C or csh equivalent. It is important to use braces to delay evaluation. **foreach** will assign the elements of the list to the variable before evaluating the script. \

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# while example 
dset x 1.1 
while {[dval x]  100} { 
  circle c 0 0 x 
  dset x x*x 
} 
# for example 
# incr var d, increments a variable of d (default 1) 
for {set i 0} {$i  10} {incr i} { 
  dset angle $i*pi/10 
  point p$i cos(angle0 sin(angle) 0 
} 
# foreach example 
foreach object {crapo tomson lucas} {display $object} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_2_5_3 break, continue

Syntax:                  

~~~~~
break 
continue 
~~~~~

Within loops, the **break** and **continue** commands have the same effect as in C. 

**break** interrupts the innermost loop and **continue** jumps to the next iteration. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# search the index for which t$i has value ;secret; 
for {set i 1} {$i = 100} {incr i} { 
  if {[set t$i] == ;secret;} break; 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsection occt_draw_2_6 Procedures

TCL can be extended by defining procedures using the **proc** command, which sets up a context of local variables, binds arguments and executes a TCL script. 

The only problematic aspect of procedures is that variables are strictly local, and as they are implicitly created when used, it may be difficult to detect errors. 

There are two means of accessing a variable outside the scope of the current procedures: **global** declares a global variable (a variable outside all procedures); **upvar** accesses a variable in the scope of the caller. Since arguments in TCL are always string values, the only way to pass Draw variables is by reference, i.e. passing the name of the variable and using the **upvar** command as in the following examples. 

As TCL is not a strongly typed language it is very difficult to detect programming errors and debugging can be tedious. TCL procedures are, of course, not designed for large scale software development but for testing and simple command or interactive writing. 


@subsubsection occt_draw_2_6_1 proc

Syntax:

~~~~~
proc argumentlist script 
~~~~~

**proc** defines a procedure. An argument may have a default value. It is then a list of the form {argument value}. The script is the body of the procedure. 

**return** gives a return value to the procedure. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# simple procedure 
proc hello {} { 
  puts ;hello world; 
} 
# procedure with arguments and default values 
proc distance {x1 y1 {x2 0} {y2 0}} { 
  set d [expr (x2-x1)*(x2-x1) + (y2-y1)*(y2-y1)] 
  return [expr sqrt(d)] 
} 
proc fact n { 
  if {$n == 0} {return 1} else { 
    return [expr n*[fact [expr n -1]]] 
  } 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@subsubsection occt_draw_2_6_2 global, upvar

Syntax:                 

~~~~~
global varname [varname ...] 
upvar varname localname [varname localname ...] 
~~~~~


**global** accesses high level variables. Unlike C, global variables are not visible in procedures. 

**upvar** gives a local name to a variable in the caller scope. This is useful when an argument is the name of a variable instead of a value. This is a call by reference and is the only way to use Draw variables as arguments. 

**Note** that in the following examples the \$ character is always necessarily used to access the arguments.
 
**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# convert degree to radian 
# pi is a global variable 
proc deg2rad (degree} { 
  return [dval pi*$degree/2.] 
} 
# create line with a point and an angle 
proc linang {linename x y angle} { 
  upvar linename l 
  line l $x $y cos($angle) sin($angle) 
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@section occt_draw_3 Basic Commands

This chapter describes all the commands defined in the basic Draw package. Some are TCL commands, but most of them have been formulated in Draw. These commands are found in all Draw applications. The commands are grouped into four sections: 

  * General commands, which are used for Draw and TCL management.
  * Variable commands, which are used to manage Draw variables such as storing and dumping.
  * Graphic commands, which are used to manage the graphic system, and so pertain to views.
  * Variable display commands, which are used to manage the display of objects within given views.

Note that Draw also features a GUI task bar providing an alternative way to give certain general, graphic and display commands 


@subsection occt_draw_3_1 General commands

This section describes several useful commands:

  * **help** to get information, 
  * **source** to eval a script from a file, 
  * **spy** to capture the commands in a file,
  * **cpulimit** to limit the process cpu time, 
  * **wait** to waste some time, 
  * **chrono** to time commands. 

@subsubsection occt_draw_3_1_1 help

Syntax:                  

~~~~~
help [command [helpstring group]] 
~~~~~

Provides help or modifies the help information. 

**help** without arguments lists all groups and the commands in each group. 

Specifying the command returns its syntax and in some cases, information on the command, The joker \* is automatically added at the end so that all completing commands are returned as well. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# Gives help on all commands starting with *a* 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@subsubsection occt_draw_3_1_2 source

Syntax:

~~~~~
source filename 
~~~~~
Executes a file. 

The **exit** command will terminate the file. 

@subsubsection occt_draw_3_1_3 spy

Syntax:                  

~~~~~
spy [filename] 
~~~~~

Saves interactive commands in the file. If spying has already been performed, the current file is closed. **spy** without an argument closes the current file and stops spying. If a file already exists, the file is overwritten. Commands are not appended. 

If a command returns an error it is saved with a comment mark. 

The file created by **spy** can be executed with the **source** command. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# all commands will be saved in the file ;session; 
spy session 
# the file ;session; is closed and commands are not saved 
spy 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



@subsubsection occt_draw_3_1_4 cpulimit

Syntax:                  

~~~~~
cpulimit [nbseconds] 
~~~~~

**cpulimit**limits a process after the number of seconds specified in nbseconds. It is used in tests to avoid infinite loops. **cpulimit** without arguments removes all existing limits. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
#limit cpu to one hour 
cpulimit 3600 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_3_1_5 wait

Syntax:
~~~~~
wait [nbseconds] 
~~~~~
Suspends execution for the number of seconds specified in *nbseconds*. The default value is ten (10) seconds. This is a useful command for a slide show. 

~~~~~
# You have ten seconds ... 
wait 
~~~~~

@subsubsection occt_draw_3_1_6 chrono

Syntax:                  

~~~~~
chrono [ name start/stop/reset/show] 
~~~~~

Without arguments, **chrono** activates Draw chronometers. The elapsed time ,cpu system and cpu user times for each command will be printed. 

With arguments, **chrono** is used to manage activated chronometers. You can perform the following actions with a chronometer. 
  * run the chronometer (start).
  * stop the chronometer (stop).
  * reset the chronometer to 0 (reset).
  * display the current time (show).

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
chrono 
==Chronometers activated. 
ptorus t 20 5 
==Elapsed time: 0 Hours 0 Minutes 0.0318 Seconds 
==CPU user time: 0.01 seconds 
==CPU system time: 0 seconds 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsection occt_draw_3_2  Variable management commands

@subsubsection occt_draw_3_2_1 isdraw, directory

Syntax:                  
~~~~~
isdraw varname 
directory [pattern] 
~~~~~

**isdraw** tests to see if a variable is a Draw variable. **isdraw** will return 1 if there is a Draw value attached to the variable. 

Use **directory** to return a list of all Draw global variables matching a pattern. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
set a 1 
isdraw a 
=== 0 

dset a 1 
isdraw a 
=== 1 

circle c 0 0 1 0 5 
isdraw c 
=== 1 

# to destroy all Draw objects with name containing curve 
foreach var [directory *curve*] {unset $var} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@subsubsection occt_draw_3_2_2 whatis, dump

Syntax:

~~~~~
whatis varname [varname ...] 
dump varname [varname ...] 
~~~~~

**whatis** returns short information about a Draw variable. This is usually the type name. 

**dump** returns a brief type description, the coordinates, and if need be, the parameters of a Draw variable. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
circle c 0 0 1 0 5 
whatis c 
c is a 2d curve 

dump c 

***** Dump of c ***** 
Circle 
Center :0, 0 
XAxis :1, 0 
YAxis :-0, 1 
Radius :5 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Note** The behavior of *whatis* on other variables (not Draw) is not excellent. 


@subsubsection occt_draw_3_2_3 rename, copy

Syntax:      
~~~~~
rename varname tovarname [varname tovarname ...] 
copy varname tovarname [varname tovarname ...] 
~~~~~

  * **rename** changes the name of a Draw variable. The original variable will no longer exist. Note that the content is not modified. Only the name is changed. 
  * **copy** creates a new variable with a copy of the content of an existing variable. The exact behavior of **copy** is type dependent; in the case of certain topological variables, the content may still be shared. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
circle c1 0 0 1 0 5 
rename c1 c2 

# curves are copied, c2 will not be modified 
copy c2 c3 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_3_2_4 datadir, save, restore

Syntax:
~~~~~
datadir [directory] 
save variable [filename] 
restore filename [variablename] 
~~~~~

  * **datadir** without arguments prints the path of the current data directory. 
  * **datadir** with an argument sets the data directory path. \

If the path starts with a dot (.) only the last directory name will be changed in the path. 

  * **save** writes a file in the data directory with the content of a variable. By default the name of the file is the name of the variable. To give a different name use a second argument. 
  * **restore** reads the content of a file in the data directory in a local variable. By default, the name of the variable is the name of the file. To give a different name, use a second argument. 

The exact content of the file is type-dependent. They are usually ASCII files and so, architecture independent. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# note how TCL accesses shell environment variables 
# using $env() 
datadir 
==. 

datadir $env(WBCONTAINER)/data/default 
==/adv_20/BAG/data/default 

box b 10 20 30 
save b theBox 
==/adv_20/BAG/data/default/theBox 

# when TCL does not find a command it tries a shell command 
ls [datadir] 
== theBox 

restore theBox 
== theBox 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsection occt_draw_3_3 User defined commands

*DrawTrSurf* provides commands to create and display a Draw **geometric** variable from a *Geom_Geometry* object and also get a *Geom_Geometry* object from a Draw geometric variable name. 

*DBRep* provides commands to create and display a Draw **topological** variable from a *TopoDS_Shape* object and also get a *TopoDS_Shape* object from a Draw topological variable name. 

@subsubsection occt_draw_3_3_1 set

#### In *DrawTrSurf* package:

~~~~~
void Set(Standard_CString& Name,const gp_Pnt& G) ; 
void Set(Standard_CString& Name,const gp_Pnt2d& G) ; 
void Set(Standard_CString& Name, 
const Handle(Geom_Geometry)& G) ; 
void Set(Standard_CString& Name, 
const Handle(Geom2d_Curve)& C) ; 
void Set(Standard_CString& Name, 
const Handle(Poly_Triangulation)& T) ; 
void Set(Standard_CString& Name, 
const Handle(Poly_Polygon3D)& P) ; 
void Set(Standard_CString& Name, 
const Handle(Poly_Polygon2D)& P) ; 
~~~~~

#### In *DBRep* package:

~~~~~
void Set(const Standard_CString Name, 
const TopoDS_Shape& S) ; 
~~~~~

Example of *DrawTrSurf*

~~~~~
Handle(Geom2d_Circle) C1 = new Geom2d_Circle 
(gce_MakeCirc2d (gp_Pnt2d(50,0,) 25)); 
DrawTrSurf::Set(char*, C1); 
~~~~~

Example of *DBRep* 

~~~~~
TopoDS_Solid B; 
B = BRepPrimAPI_MakeBox (10,10,10); 
DBRep::Set(char*,B); 
~~~~~

@subsubsection occt_draw_3_3_2 get

#### In *DrawTrSurf* package:
 
~~~~~
Handle_Geom_Geometry Get(Standard_CString& Name) ; 
~~~~~

#### In *DBRep* package:

~~~~~
TopoDS_Shape Get(Standard_CString& Name, 
const TopAbs_ShapeEnum Typ = TopAbs_SHAPE, 
const Standard_Boolean Complain 
= Standard_True) ; 
~~~~~

Example of *DrawTrSurf*

~~~~~
Standard_Integer MyCommand 
(Draw_Interpretor& theCommands, 
Standard_Integer argc, char** argv) 
{...... 
// Creation of a Geom_Geometry from a Draw geometric 
// name 
Handle (Geom_Geometry) aGeom= DrawTrSurf::Get(argv[1]); 
} 
~~~~~

Example of *DBRep*

~~~~~
Standard_Integer MyCommand 
(Draw_Interpretor& theCommands, 
Standard_Integer argc, char** argv) 
{...... 
// Creation of a TopoDS_Shape from a Draw topological 
// name 
TopoDS_Solid B = DBRep::Get(argv[1]); 
} 
~~~~~

@section occt_draw_4 Graphic Commands

Graphic commands are used to manage the Draw graphic system. Draw provides a 2d and a 3d viewer with up to 30 views. Views are numbered and the index of the view is displayed in the window’s title. Objects are displayed in all 2d views or in all 3d views, depending on their type. 2d objects can only be viewed in 2d views while 3d objects – only in 3d views correspondingly. 

@subsection occt_draw_4_1 Axonometric viewer

@subsubsection occt_draw_4_1_1 view, delete

Syntax:                  
~~~~~
view index type [X Y W H] 
delete [index] 
~~~~~

**view** is the basic view creation command: it creates a new view with the given index. If a view with this index already exits, it is deleted. The view is created with default parameters and X Y W H are the position and dimensions of the window on the screen. Default values are 0, 0, 500, 500. 

As a rule it is far simpler either to use the procedures **axo**, **top**, **left** or to click on the desired view type in the menu under *Views* in the task bar.. 

**delete** deletes a view. If no index is given, all the views are deleted. 

Type selects from the following range: 

  * *AXON* : Axonometric view
  * *PERS* : Perspective view
  * <i>+X+Y</i> : View on both axes (i.e. a top view), other codes are <i>-X+Y</i>, <i>+Y-Z</i>, etc.
  * <i>-2D-</i> : 2d view

The index, the type, the current zoom are displayed in the window title . 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# this is the content of the mu4 procedure 
proc mu4 {} { 
delete 
view 1 +X+Z 320 20 400 400 
view 2 +X+Y 320 450 400 400 
view 3 +Y+Z 728 20 400 400 
view 4 AXON 728 450 400 400 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

See also: **axo, pers, top, bottom, left, right, front, back, mu4, v2d, av2d, smallview** 

@subsubsection occt_draw_4_1_2  axo, pers, top, ...

Syntax:      

~~~~~
axo 
pers 
... 
smallview type 
~~~~~

All these commands are procedures used to define standard screen layout. They delete all existing views and create new ones. The layout usually complies with the European convention, i.e. a top view is under a front view. 

  * **axo** creates a large window axonometric view;
  * **pers** creates a large window perspective view;
  * **top**, **bottom**, **left**, **right**, **front**, **back** create a large window axis view;
  * **mu4** creates four small window views: front, left, top and axo.
  * **v2d** creates a large window 2d view.
  * **av2d** creates two small window views, one 2d and one axo
  * **smallview** creates a view at the bottom right of the screen of the given type. 

See also: **view**, **delete** 

@subsubsection occt_draw_4_1_3 mu, md, 2dmu, 2dmd, zoom, 2dzoom

Syntax:

~~~~~
    mu [index] value 
    2dmu [index] value 
    zoom [index] value 
    wzoom 
~~~~~

* **mu** (magnify up) increases the zoom in one or several views by a factor of 10%. 
* **md** (magnify down) decreases the zoom by the inverse factor. **2dmu** and **2dmd** 
perform the same on one or all 2d views. 
* **zoom** and **2dzoom** set the zoom factor to a value specified by you. The current zoom factor is always displayed in the window’s title bar. Zoom 20 represents a full screen view in a large window; zoom 10, a full screen view in a small one. 
* **wzoom** (window zoom) allows you to select the area you want to zoom in on with the mouse. You will be prompted to give two of the corners of the area that you want to magnify and the rectangle so defined will occupy the window of the view. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
    # set a zoom of 2.5 
    zoom 2.5 

    # magnify by 10% 
    mu 1 

    # magnify by 20% 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
See also: **fit**, **2dfit** 


@subsubsection occt_draw_4_14 pu, pd, pl, pr, 2dpu, 2dpd, 2dpl, 2dpr

Syntax:                  

~~~~~
pu [index] 
pd [index] 
~~~~~

The <i>p_</i> commands are used to pan. **pu** and **pd** pan up and down respectively; **pl** and **pr** pan to the left and to the right respectively. Each time the view is displaced by 40 pixels. When no index is given, all views will pan in the direction specified. 
~~~~~
# you have selected one anonometric view
pu
# or
pu 1

# you have selected an mu4 view; the object in the third view will pan up
pu 3
~~~~~
See also: **fit**, **2dfit** 


@subsubsection occt_draw_4_1_5 fit, 2dfit

Syntax:      

~~~~~
fit [index] 
2dfit [index] 
~~~~~

**fit** computes the best zoom and pans on the content of the view. The content of the view will be centered and fit the whole window. 

When fitting all views a unique zoom is computed for all the views. All views are on the same scale. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# fit only view 1 
fit 1 
# fit all 2d views 
2dfit 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
See also: **zoom**, **mu**, **pu** 


@subsubsection occt_draw_4_1_6 u, d, l, r

Syntax:      

~~~~~
u [index] 
d [index] 
l [index] 
r [index] 
~~~~~

**u**, **d**, **l**, **r** Rotate the object in view around its axis by five degrees up, down, left or right respectively. This command is restricted to axonometric and perspective views. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# rotate the view up 
u 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_1_7 focal, fu, fd

Syntax:                  
~~~~~
focal [f] 
fu [index] 
fd [index] 
~~~~~

* **focal** changes the vantage point in perspective views. A low f value increases the perspective effect; a high one give a perspective similar to that of an axonometric view. The default value is 500. 
* **fu** and **fd** increase or decrease the focal value by 10%. **fd** makes the eye closer to the object. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
pers 
repeat 10 fd 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Note**: Do not use a negative or null focal value. 

See also: **pers** 

@subsubsection occt_draw_4_1_8 color

Syntax: 

~~~~~
color index name 
~~~~~

**color** sets the color to a value. The index of the *color* is a value between 0 and 15. The name is an X window color name. The list of these can be found in the file *rgb.txt* in the X library directory. 

The default values are: 0 White, 1 Red, 2 Green, 3 Blue, 4 Cyan, 5 Gold, 6 Magenta, 7 Marron, 8 Orange, 9 Pink, 10 Salmon, 11 Violet, 12 Yellow, 13 Khaki, 14 Coral. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# change the value of blue 
color 3 "navy blue" 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


**Note** that the color change will be visible on the next redraw of the views, for example, after *fit* or *mu*, etc. 

@subsubsection occt_draw_4_1_9 dtext

Syntax:      
~~~~~
dtext [x y [z]] string 
~~~~~

**dtext** displays a string in all 3d or 2d views. If no coordinates are given, a graphic selection is required. If two coordinates are given, the text is created in a 2d view at the position specified. With 3 coordinates, the text is created in a 3d view. 

The coordinates are real space coordinates. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# mark the origins 
dtext 0 0 bebop 
dtext 0 0 0 bebop 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_1_10 hardcopy, hcolor, xwd

Syntax:      
~~~~~
hardcopy [index] 
hcolor index width gray 
xwd [index] filename 
~~~~~

* **hardcopy** creates a postcript file called a4.ps in the current directory. This file contains the postscript description of the view index, and will allow you to print the view. 
* **hcolor** lets you change the aspect of lines in the postscript file. It allows to specify a width and a gray level for one of the 16 colors. **width** is measured in points with default value as 1, **gray** is the gray level from 0 = black to 1 = white with default value as 0. All colors are bound to the default values at the beginning. 
* **xwd** creates an X window xwd file from an active view. By default, the index is set to1. To visualize an xwd file, use the unix command **xwud**. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# all blue lines (color 3) 
# will be half-width and gray 
hcolor 3 0.5 

# make a postscript file and print it 
hardcopy 
lpr a4.ps 

# make an xwd file and display it 
xwd theview 
xwud -in theview 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Note:** When more than one view is present, specify the index of the view. 

Only use a postscript printer to print postscript files. 

See also: **color** 


@subsubsection occt_draw_4_1_11 wclick, pick

Syntax:      
~~~~~
wclick 
pick index X Y Z b [nowait] 
~~~~~

**wclick** defers an event until the mouse button is clicked. The message <code>just click</code> is displayed. 

Use the **pick** command to get graphic input. The arguments must be names for variables where the results are stored. 
  * index: index of the view where the input was made.
  * X,Y,Z: 3d coordinates in real world.
  * b: b is the mouse button 1,2 or 3.

When there is an extra argument, its value is not used and the command does not wait for a click; the value of b may then be 0 if there has not been a click. 

This option is useful for tracking the pointer. 

**Note** that the results are stored in Draw numeric variables.

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# make a circle at mouse location 
pick index x y z b 
circle c x y z 0 0 1 1 0 0 0 30 

# make a dynamic circle at mouse location 
# stop when a button is clicked 
# (see the repaint command) 

dset b 0 
while {[dval b] == 0} { 
pick index x y z b nowait 
circle c x y z 0 0 1 1 0 0 0 30 
repaint 
} 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
See also: **repaint** 


Draw provides commands to manage the display of objects. 
* **display**, **donly** are used to display, 
* **erase**, **clear**, **2dclear** to erase. 
* **autodisplay** command is used to check whether variables are displayed when created. 

The variable name "." (dot) has a special status in Draw. Any Draw command expecting a Draw object as argument can be passed a dot. The meaning of the dot is the following. 
  * If the dot is an input argument, a graphic selection will be made. Instead of getting the object from a variable, Draw will ask you to select an object in a view.
  * If the dot is an output argument, an unnamed object will be created. Of course this makes sense only for graphic objects: if you create an unnamed number you will not be able to access it. This feature is used when you want to create objects for display only.
  * If you do not see what you expected while executing loops or sourcing files, use the **repaint** and **dflush** commands.

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# OK use dot to dump an object on the screen 
dump . 

point . x y z 

#Not OK. display points on a curve c 
# with dot no variables are created 
for {set i 0} {$i = 10} {incr i} { 
cvalue c $i/10 x y z 
point . x y z 
} 

# point p x y z 
# would have displayed only one point 
# because the precedent variable content is erased 

# point p$i x y z 
# is an other solution, creating variables 
# p0, p1, p2, .... 

# give a name to a graphic object 
rename . x 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@subsubsection occt_draw_4_1_12 autodisplay

Syntax:      

~~~~~
autodisplay [0/1] 
~~~~~

By default, Draw automatically displays any graphic object as soon as it is created. This behavior known as autodisplay can be removed with the command **autodisplay**. Without arguments, **autodisplay** toggles the autodisplay mode. The command always returns the current mode. 

When **autodisplay** is off, using the dot return argument is ineffective. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# c is displayed 
circle c 0 0 1 0 5 

# toggle the mode 
autodisplay 
== 0 
circle c 0 0 1 0 5 

# c is erased, but not displayed 
display c 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_1_13 display, donly

Syntax:      
~~~~~
display varname [varname ...] 
donly varname [varname ...] 
~~~~~

* **display** makes objects visible. 
* **donly** *display only* makes objects visible and erases all other objects. It is very useful to extract one object from a messy screen. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
\# to see all objects 
foreach var [directory] {display $var} 

\# to select two objects and erase the other ones 
donly . . 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


@subsubsection occt_draw_4_1_14 erase, clear, 2dclear

Syntax:      

~~~~~
erase [varname varname ...] 
clear 
2dclear 
~~~~~

**erase** removes objects from all views. **erase** without arguments erases everything in 2d and 3d. 

**clear** erases only 3d objects and **2dclear** only 2d objects. **erase** without arguments is similar to  **clear; 2dclear**.


**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
# erase eveerything with a name starting with c_ 
foreach var [directory c_*] {erase $var} 

# clear 2d views 
2d clear 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_1_15 repaint, dflush


Syntax:

~~~~~
repaint 
dflush 
~~~~~

* **repaint** forces repainting of views. 
* **dflush** flushes the graphic buffers. 

These commands are useful within loops or in scripts. 

When an object is modified or erased, the whole view must be repainted. To avoid doing this too many times, Draw sets up a flag and delays the repaint to the end of the command in which the new prompt is issued. In a script, you may want to display the result of a change immediately. If the flag is raised, **repaint** will repaint the views and clear the flag. 

Graphic operations are buffered by Draw (and also by the X system). Usually the buffer is flushed at the end of a command and before graphic selection. If you want to flush the buffer from inside a script, use the **dflush** command. 

See also: <a href="#occt_draw_4_1_11">pick</a> command.  

@subsection occt_draw_4_2 AIS viewer – view commands

@subsubsection occt_draw_4_2_1 vinit

Syntax:                  
~~~~~
vinit 
~~~~~
Creates the 3D viewer window 

@subsubsection occt_draw_4_2_2 vhelp

Syntax:
~~~~~
vhelp 
~~~~~
Displays help in the 3D viewer window. The help consists in a list of hotkeys and their functionalities. 

@subsubsection occt_draw_4_2_3 vtop

Syntax:
~~~~~
vtop 
~~~~~

Displays top view in the 3D viewer window. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
vinit 
box b 10 10 10 
vdisplay b 
vfit 
vtop 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_2_4 vaxo

Syntax:                  
~~~~~
vaxo 
~~~~~

Displays axonometric view in the 3D viewer window. 

**Example:** 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.cpp}
vinit 
box b 10 10 10 
vdisplay b 
vfit 
vaxo 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

@subsubsection occt_draw_4_2_5 vsetbg

Syntax:                  
~~~~~
vsetbg imagefile [filltype] 
~~~~~

Loads image file as background. *filltype* must be NONE, CENTERED, TILED or STRETCH. 

**Example:** 
~~~~~
vinit 
vsetbg myimage.brep CENTERED 
~~~~~

@subsubsection occt_draw_4_2_6 vclear

Syntax:                  
~~~~~
vclear 
~~~~~
Removes all objects from the viewer. 

@subsubsection occt_draw_4_2_7 vrepaint

Syntax:                  
~~~~~
vrepaint 
~~~~~
Forcedly redisplays the shape in the 3D viewer window. 

@subsubsection occt_draw_4_2_8 vfit

Syntax:                  
~~~~~
vfit 
~~~~~
Automatic zoom/panning. Objects in the view are visualized to occupy the maximum surface. 

@subsubsection occt_draw_4_2_9 vzfit

Syntax:                  
~~~~~
vzfit 
~~~~~

Automatic depth panning. Objects in the view are visualized to occupy the maximum 3d space. 

@subsubsection occt_draw_4_2_10  vreadpixel

Syntax:     
~~~~~
vreadpixel xPixel yPixel [{rgb|rgba|depth|hls|rgbf|rgbaf}=rgba] [name] 
~~~~~
Read pixel value for active view.


@subsubsection occt_draw_4_2_11  vselect

Syntax:     
~~~~~
vselect x1 y1 [x2 y2 [x3 y3 ... xn yn]] [shift_selection = 0|1]
~~~~~

Emulates different types of selection:

  * single mouse click selection
  * selection with a rectangle having the upper left and bottom right corners in <i>(x1,y1)</i> and <i>(x2,y2)</i> respectively
  * selection with a polygon having the corners in pixel positions <i>(x1,y1), (x2,y2),…, (xn,yn)</i>
  * any of these selections if shift_selection is set to 1.

@subsubsection occt_draw_4_2_12  vmoveto

Syntax:     

~~~~~
vmoveto x y
~~~~~
Emulates cursor movement to pixel position (x,y).

@subsubsection occt_draw_4_2_13  vviewparams

Syntax:     
~~~~~
vviewparams [scale center_X center_Y proj_X proj_Y proj_Z up_X up_Y up_Z at_X at_Y at_Z]
~~~~~
Gets or sets the current view characteristics.

@subsubsection occt_draw_4_2_14  vchangeselected

Syntax:     
~~~~~
vchangeselected shape
~~~~~
Adds a shape to selection or removes one from it.

@subsubsection occt_draw_4_2_15  vzclipping

Syntax:     
~~~~~
vzclipping [mode] [depth width]
~~~~~
Gets or sets ZClipping mode, width and depth, where
 - *mode = OFF|BACK|FRONT|SLICE*
 - *depth* is a real value from segment [0,1]
 - *width* is a real value from segment [0,1]

@subsubsection occt_draw_4_2_16  vnbselected

Syntax:     
~~~~~
vnbselected
~~~~~
Returns the number of selected objects in the interactive context.

@subsubsection occt_draw_4_2_17  vantialiasing

Syntax:     
~~~~~
valntialiasing 1|0
~~~~~
Sets antialiasing if the command is called with 1 or unsets otherwise.

@subsubsection occt_draw_4_2_18  vpurgedisplay

Syntax:     
~~~~~
vpurgedisplay [CollectorToo = 0|1]
~~~~~
Removes structures which do not belong to objects displayed in neutral point.

@subsubsection occt_draw_4_2_19  vhlr

Syntax:     
~~~~~
vhlr is_enabled={on|off}
~~~~~
Switches hidden line removal (computed) mode on/off.

@subsubsection occt_draw_4_2_20  vhlrtype

Syntax:     
~~~~~
vhlrtype  algo_type={algo|polyalgo} [shape_1 ... shape_n]
~~~~~

Changes the type of HLR algorithm used for shapes.
If the algo_type is algo, the exact HLR algorithm is used, otherwise the polygonal algorithm is used for defined shapes. 

If no shape is specified through the command arguments, the given HLR algorithm_type is applied to all *AIS_Shape* isntances in the current context, and the command also changes the default HLR algorithm type.

**Note** that this command works with instances of *AIS_Shape* or derived classes only, other interactive object types are ignored.


@subsection occt_draw_4_3 AIS viewer – display commands

@subsubsection occt_draw_4_3_1 vdisplay

Syntax: 
~~~~~                 
vdisplay name1 [name2] … [name n] 
~~~~~

Displays named objects. 

**Example:** 
~~~~~ 
vinit 
box b 40 40 40 10 10 10 
psphere s 20 
vdisplay s b 
vfit 
~~~~~ 

@subsubsection occt_draw_4_3_2 vdonly

Syntax:                  
~~~~~
vdonly [name1] … [name n]
~~~~~ 

Displays only selected or named objects. If there are no selected or named objects, nothing is done. 

**Example:** 
~~~~~ 
vinit 
box b 40 40 40 10 10 10 
psphere s 20 
vdonly b 
vfit
~~~~~ 
 
@subsubsection occt_draw_4_3_3 vdisplayall

Syntax:                  
~~~~~ 
vdisplayall 
~~~~~ 

Displays all created objects. 

**Example:** 
~~~~~ 
vinit 
box b 40 40 40 10 10 10 
psphere s 20 
vdisplayall 
vfit 
~~~~~ 

@subsubsection occt_draw_4_3_4 verase

Syntax:                  
~~~~~
verase [name1] [name2] … [name n]
~~~~~ 

Erases some selected or named objects. If there are no selected or named objects, the whole viewer is erased. 

**Example:** 
~~~~~
vinit 
box b1 40 40 40 10 10 10 
box b2 -40 -40 -40 10 10 10 
psphere s 20 
vdisplayall 
vfit 
# erase only first box 
verase b1 
# erase second box and sphere 
verase
~~~~~ 

@subsubsection occt_draw_4_3_5 veraseall

Syntax:                  
~~~~~
veraseall
~~~~~ 

Erases all objects displayed in the viewer. 

**Example:**
~~~~~ 
vinit 
box b1 40 40 40 10 10 10 
box b2 -40 -40 -40 10 10 10 
psphere s 20 
vdisplayall 
vfit 
# erase only first box 
verase b1 
# erase second box and sphere 
verseall
~~~~~ 

@subsubsection occt_draw_4_3_6 vsetdispmode

Syntax:                  
~~~~~
vsetdispmode [name] mode(0,1,2,3)
~~~~~ 

Sets display mode for all, selected or named objects. 
* *0* (*WireFrame*), 
* *1* (*Shading*), 
* *2* (*Quick HideLineremoval*), 
* *3* (*Exact HideLineremoval*). 

**Example:** 
~~~~~
vinit 
box b 10 10 10 
vdisplay b 
vsetdispmode 1 
vfit
~~~~~
 
@subsubsection occt_draw_4_3_7 vdisplaytype

Syntax:                  
~~~~~
vdisplaytype type
~~~~~ 

Displays all objects of a given type. 
The following types are possible: *Point*, *Axis*, *Trihedron*, *PlaneTrihedron*, *Line*, *Circle*, *Plane*, *Shape*, *ConnectedShape*, *MultiConn.Shape*, *ConnectedInter.*, *MultiConn.*, *Constraint* and *Dimension*. 

@subsubsection occt_draw_4_3_8 verasetype

Syntax:                  
~~~~~
verasetype type
~~~~~ 

Erases all objects of a given type. 
Possible type is *Point*, *Axis*, *Trihedron*, *PlaneTrihedron*, *Line*, *Circle*, *Plane*, *Shape*, *ConnectedShape*, *MultiConn.Shape*, *ConnectedInter.*, *MultiConn.*, *Constraint* and *Dimension*. 

@subsubsection occt_draw_4_3_9 vtypes

Syntax:                  
~~~~~
vtypes
~~~~~ 

Makes a list of known types and signatures in AIS. 

@subsubsection occt_draw_4_3_10 vsetcolor

Syntax:                  
~~~~~
vsetcolor [shapename] colorname
~~~~~ 

Sets color for all, selected or named shapes. 
Possible *colorname* is: *BLACK*, *MATRAGRAY*, *MATRABLUE*, *ALICEBLUE*, *ANTIQUEWHITE*, *ANTIQUEWHITE1*, *ANTIQUEWHITE2*, *ANTIQUEWHITE3*, *ANTIQUEWHITE4*, *AQUAMARINE1*, *AQUAMARINE2*, *AQUAMARINE4*, *AZURE*, *AZURE2*, *AZURE3*, *AZURE4*, *BEIGE*, *BISQUE*, *BISQUE2*, *BISQUE3*, *BISQUE4*, *BLANCHEDALMOND*, *BLUE1*, *BLUE2*, *BLUE3*, *BLUE4*, *BLUEVIOLET*, *BROWN*, *BROWN1*, *BROWN2*, *BROWN3*, *BROWN4*, *BURLYWOOD*, *BURLYWOOD1*, *BURLYWOOD2*, *BURLYWOOD3*, *BURLYWOOD4*, *CADETBLUE*, *CADETBLUE1*, *CADETBLUE2*, *CADETBLUE3*, *CADETBLUE4*, *CHARTREUSE*, *CHARTREUSE1*, *CHARTREUSE2*, *CHARTREUSE3*, *CHARTREUSE4*, *CHOCOLATE*, *CHOCOLATE1*, *CHOCOLATE2*, *CHOCOLATE3*, *CHOCOLATE4*, *CORAL*, *CORAL1*, *CORAL2*, *CORAL3*, *CORAL4*, *CORNFLOWERBLUE*, *CORNSILK1*, *CORNSILK2*, *CORNSILK3*, *CORNSILK4*, *CYAN1*, *CYAN2*, *CYAN3*, *CYAN4*, *DARKGOLDENROD*, *DARKGOLDENROD1*, *DARKGOLDENROD2*, *DARKGOLDENROD3*, *DARKGOLDENROD4*, *DARKGREEN*, *DARKKHAKI*, *DARKOLIVEGREEN*, *DARKOLIVEGREEN1*, *DARKOLIVEGREEN2*, *DARKOLIVEGREEN3*, *DARKOLIVEGREEN4*, *DARKORANGE*, *DARKORANGE1*, *DARKORANGE2*, *DARKORANGE3*, *DARKORANGE4*, *DARKORCHID*, *DARKORCHID1*, *DARKORCHID2*, *DARKORCHID3*, *DARKORCHID4*, *DARKSALMON*, *DARKSEAGREEN*, *DARKSEAGREEN1*, *DARKSEAGREEN2*, *DARKSEAGREEN3*, *DARKSEAGREEN4*, *DARKSLATEBLUE*, *DARKSLATEGRAY1*, *DARKSLATEGRAY2*, *DARKSLATEGRAY3*, *DARKSLATEGRAY4*, *DARKSLATEGRAY*, *DARKTURQUOISE*, *DARKVIOLET*, *DEEPPINK*, *DEEPPINK2*, *DEEPPINK3*, *DEEPPINK4*, *DEEPSKYBLUE1*, *DEEPSKYBLUE2*, *DEEPSKYBLUE3*, *DEEPSKYBLUE4*, *DODGERBLUE1*, *DODGERBLUE2*, *DODGERBLUE3*, *DODGERBLUE4*, *FIREBRICK*, *FIREBRICK1*, *FIREBRICK2*, *FIREBRICK3*, *FIREBRICK4*, *FLORALWHITE*, *FORESTGREEN*, *GAINSBORO*, *GHOSTWHITE*, *GOLD*, *GOLD1*, *GOLD2*, *GOLD3*, *GOLD4*, *GOLDENROD*, *GOLDENROD1*, *GOLDENROD2*, *GOLDENROD3*, *GOLDENROD4*, *GRAY*, *GRAY0*, *GRAY1*, *GRAY10*, *GRAY11*, *GRAY12*, *GRAY13*, *GRAY14*, *GRAY15*, *GRAY16*, *GRAY17*, *GRAY18*, *GRAY19*, *GRAY2*, *GRAY20*, *GRAY21*, *GRAY22*, *GRAY23*, *GRAY24*, *GRAY25*, *GRAY26*, *GRAY27*, *GRAY28*, *GRAY29*, *GRAY3*, *GRAY30*, *GRAY31*, *GRAY32*, *GRAY33*, *GRAY34*, *GRAY35*, *GRAY36*, *GRAY37*, *GRAY38*, *GRAY39*, *GRAY4*, *GRAY40*, *GRAY41*, *GRAY42*, *GRAY43*, *GRAY44*, *GRAY45*, *GRAY46*, *GRAY47*, *GRAY48*, *GRAY49*, *GRAY5*, *GRAY50*, *GRAY51*, *GRAY52*, *GRAY53*, *GRAY54*, *GRAY55*, *GRAY56*, *GRAY57*, *GRAY58*, *GRAY59*, *GRAY6*, *GRAY60*, *GRAY61*, *GRAY62*, *GRAY63*, *GRAY64*, *GRAY65*, *GRAY66*, *GRAY67*, *GRAY68*, *GRAY69*, *GRAY7*, *GRAY70*, *GRAY71*, *GRAY72*, *GRAY73*, *GRAY74*, *GRAY75*, *GRAY76*, *GRAY77*, *GRAY78*, *GRAY79*, *GRAY8*, *GRAY80*, *GRAY81*, *GRAY82*, *GRAY83*, *GRAY85*, *GRAY86*, *GRAY87*, *GRAY88*, *GRAY89*, *GRAY9*, *GRAY90*, *GRAY91*, *GRAY92*, *GRAY93*, *GRAY94*, *GRAY95*, *GREEN*, *GREEN1*, *GREEN2*, *GREEN3*, *GREEN4*, *GREENYELLOW*, *GRAY97*, *GRAY98*, *GRAY99*, *HONEYDEW*, *HONEYDEW2*, *HONEYDEW3*, *HONEYDEW4*, *HOTPINK*, *HOTPINK1*, *HOTPINK2*, *HOTPINK3*, *HOTPINK4*, *INDIANRED*, *INDIANRED1*, *INDIANRED2*, *INDIANRED3*, *INDIANRED4*, *IVORY*, *IVORY2*, *IVORY3*, *IVORY4*, *KHAKI*, *KHAKI1*, *KHAKI2*, *KHAKI3*, *KHAKI4*, *LAVENDER*, *LAVENDERBLUSH1*, *LAVENDERBLUSH2*, *LAVENDERBLUSH3*, *LAVENDERBLUSH4*, *LAWNGREEN*, *LEMONCHIFFON1*, *LEMONCHIFFON2*, *LEMONCHIFFON3*, *LEMONCHIFFON4*, *LIGHTBLUE*, *LIGHTBLUE1*, *LIGHTBLUE2*, *LIGHTBLUE3*, *LIGHTBLUE4*, *LIGHTCORAL*, *LIGHTCYAN1*, *LIGHTCYAN2*, *LIGHTCYAN3*, *LIGHTCYAN4*, *LIGHTGOLDENROD*, *LIGHTGOLDENROD1*, *LIGHTGOLDENROD2*, *LIGHTGOLDENROD3*, *LIGHTGOLDENROD4*, *LIGHTGOLDENRODYELLOW*, *LIGHTGRAY*, *LIGHTPINK*, *LIGHTPINK1*, *LIGHTPINK2*, *LIGHTPINK3*, *LIGHTPINK4*, *LIGHTSALMON1*, *LIGHTSALMON2*, *LIGHTSALMON3*, *LIGHTSALMON4*, *LIGHTSEAGREEN*, *LIGHTSKYBLUE*, *LIGHTSKYBLUE1*, *LIGHTSKYBLUE2*, *LIGHTSKYBLUE3*, *LIGHTSKYBLUE4*, *LIGHTSLATEBLUE*, *LIGHTSLATEGRAY*, *LIGHTSTEELBLUE*, *LIGHTSTEELBLUE1*, *LIGHTSTEELBLUE2*, *LIGHTSTEELBLUE3*, *LIGHTSTEELBLUE4*, *LIGHTYELLOW*, *LIGHTYELLOW2*, *LIGHTYELLOW3*, *LIGHTYELLOW4*, *LIMEGREEN*, *LINEN*, *MAGENTA1*, *MAGENTA2*, *MAGENTA3*, *MAGENTA4*, *MAROON*, *MAROON1*, *MAROON2*, *MAROON3*, *MAROON4*, *MEDIUMAQUAMARINE*, *MEDIUMORCHID*, *MEDIUMORCHID1*, *MEDIUMORCHID2*, *MEDIUMORCHID3*, *MEDIUMORCHID4*, *MEDIUMPURPLE*, *MEDIUMPURPLE1*, *MEDIUMPURPLE2*, *MEDIUMPURPLE3*, *MEDIUMPURPLE4*, *MEDIUMSEAGREEN*, *MEDIUMSLATEBLUE*, *MEDIUMSPRINGGREEN*, *MEDIUMTURQUOISE*, *MEDIUMVIOLETRED*, *MIDNIGHTBLUE*, *MINTCREAM*, *MISTYROSE*, *MISTYROSE2*, *MISTYROSE3*, *MISTYROSE4*, *MOCCASIN*, *NAVAJOWHITE1*, *NAVAJOWHITE2*, *NAVAJOWHITE3*, *NAVAJOWHITE4*, *NAVYBLUE*, *OLDLACE*, *OLIVEDRAB*, *OLIVEDRAB1*, *OLIVEDRAB2*, *OLIVEDRAB3*, *OLIVEDRAB4*, *ORANGE*, *ORANGE1*, *ORANGE2*, *ORANGE3*, *ORANGE4*, *ORANGERED*, *ORANGERED1*, *ORANGERED2*, *ORANGERED3*, *ORANGERED4*, *ORCHID*, *ORCHID1*, *ORCHID2*, *ORCHID3*, *ORCHID4*, *PALEGOLDENROD*, *PALEGREEN*, *PALEGREEN1*, *PALEGREEN2*, *PALEGREEN3*, *PALEGREEN4*, *PALETURQUOISE*, *PALETURQUOISE1*, *PALETURQUOISE2*, *PALETURQUOISE3*, *PALETURQUOISE4*, *PALEVIOLETRED*, *PALEVIOLETRED1*, *PALEVIOLETRED2*, *PALEVIOLETRED3*, *PALEVIOLETRED4*, *PAPAYAWHIP*, *PEACHPUFF*, *PEACHPUFF2*, *PEACHPUFF3*, *PEACHPUFF4*, *PERU*, *PINK*, *PINK1*, *PINK2*, *PINK3*, *PINK4*, *PLUM*, *PLUM1*, *PLUM2*, *PLUM3*, *PLUM4*, *POWDERBLUE*, *PURPLE*, *PURPLE1*, *PURPLE2*, *PURPLE3*, *PURPLE4*, *RED*, *RED1*, *RED2*, *RED3*, *RED4*, *ROSYBROWN*, *ROSYBROWN1*, *ROSYBROWN2*, *ROSYBROWN3*, *ROSYBROWN4*, *ROYALBLUE*, *ROYALBLUE1*, *ROYALBLUE2*, *ROYALBLUE3*, *ROYALBLUE4*, *SADDLEBROWN*, *SALMON*, *SALMON1*, *SALMON2*, *SALMON3*, *SALMON4*, *SANDYBROWN*, *SEAGREEN*, *SEAGREEN1*, *SEAGREEN2*, *SEAGREEN3*, *SEAGREEN4*, *SEASHELL*, *SEASHELL2*, *SEASHELL3*, *SEASHELL4*, *BEET*, *TEAL*, *SIENNA*, *SIENNA1*, *SIENNA2*, *SIENNA3*, *SIENNA4*, *SKYBLUE*, *SKYBLUE1*, *SKYBLUE2*, *SKYBLUE3*, *SKYBLUE4*, *SLATEBLUE*, *SLATEBLUE1*, *SLATEBLUE2*, *SLATEBLUE3*, *SLATEBLUE4*, *SLATEGRAY1*, *SLATEGRAY2*, *SLATEGRAY3*, *SLATEGRAY4*, *SLATEGRAY*, *SNOW*, *SNOW2*, *SNOW3*, *SNOW4*, *SPRINGGREEN*, *SPRINGGREEN2*, *SPRINGGREEN3*, *SPRINGGREEN4*, *STEELBLUE*, *STEELBLUE1*, *STEELBLUE2*, *STEELBLUE3*, *STEELBLUE4*, *TAN*, *TAN1*, *TAN2*, *TAN3*, *TAN4*, *THISTLE*, *THISTLE1*, *THISTLE2*, *THISTLE3*, *THISTLE4*, *TOMATO*, *TOMATO1*, *TOMATO2*, *TOMATO3*, *TOMATO4*, *TURQUOISE*, *TURQUOISE1*, *TURQUOISE2*, *TURQUOISE3*, *TURQUOISE4*, *VIOLET*, *VIOLETRED*, *VIOLETRED1*, *VIOLETRED2*, *VIOLETRED3*, *VIOLETRED4*, *WHEAT*, *WHEAT1*, *WHEAT2*, *WHEAT3*, *WHEAT4*, *WHITE*, *WHITESMOKE*, *YELLOW*, *YELLOW1*, *YELLOW2*, *YELLOW3*, *YELLOW4* and *YELLOWGREEN*.

@subsubsection occt_draw_4_3_11 vunsetcolor

Syntax:                  
~~~~~
vunsetcolor [shapename]
~~~~~ 

Sets default color for all, selected or named shapes. 

@subsubsection occt_draw_4_3_12 vsettransparency

Syntax:                  
~~~~~
vsettransparency [shapename] coeficient
~~~~~ 

Sets transparency for all selected or named shapes. The *coefficient* may be between 0.0 (opaque) and 1.0 (fully transparent). 

**Warning**: at 1.0 the shape becomes invisible.
 
**Example:** 
~~~~~
vinit 
box b 10 10 10 
psphere s 20 
vdisplay b s 
vfit 
vsetdispmode 1 
vsettransparency b 0.5
~~~~~ 

@subsubsection occt_draw_4_3_13 vunsettransparency

Syntax:                  
~~~~~
vunsettransparency [shapename]
~~~~~ 

Sets default transparency (0.0) for all selected or named shapes. 

@subsubsection occt_draw_4_3_14 vsetmaterial

Syntax:                  
~~~~~
vsetmaterial [shapename] materialname
~~~~~ 

Sets material for all selected or named shapes. 

**materialname** can be *BRASS*, *BRONZE*, *COPPER*, *GOLD*, *PEWTER*, *PLASTER*, *PLASTIC*, *SILVER*, *STEEL*, *STONE*, *SHINY_PLASTIC*, *SATIN*, *METALIZED*, *NEON_GNC*, *CHROME*, *ALUMINIUM*, *OBSIDIAN*, *NEON_PHC* or *JADE*.
 
**Example:** 
~~~~~
vinit 
psphere s 20 
vdisplay s 
vfit 
vsetdispmode 1 
vsetmaterial s JADE 
~~~~~

@subsubsection occt_draw_4_3_15 vunsetmaterial

Syntax:                  
~~~~~
vunsetmaterial [shapename]
~~~~~ 

Sets default material for all selected or named shapes. 

@subsubsection occt_draw_4_3_16 vsetwidth

Syntax:                  
~~~~~
vsetwidth [shapename] coeficient
~~~~~ 

Sets width of the edges for all selected or named shapes. 
The *coefficient* may be between 0.0 and 10.0.
 
**Example:** 
~~~~~
vinit 
box b 10 10 10 
vdisplay b 
vfit 
vsetwidth b 5
~~~~~ 

@subsubsection occt_draw_4_3_17 vunsetwidth

Syntax:                  
~~~~~
vunsetwidth [shapename]
~~~~~ 

Sets default width of edges (0.0) for all selected or named shapes. 

@subsubsection occt_draw_4_3_18 vsetshading

Syntax:                  
~~~~~
vsetshading shapename [coefficient]
~~~~~ 

Sets deflection coefficient that defines the quality of the shape’s representation in the shading mode. Default coefficient is 0.0008. 

**Example:** 
~~~~~
vinit 
psphere s 20 
vdisplay s 
vfit 
vsetdispmode 1 
vsetshading s 0.005
~~~~~
 
@subsubsection occt_draw_4_3_19 vunsetshading

Syntax:                  
~~~~~
vunsetshading [shapename]
~~~~~ 

Sets default deflection coefficient (0.0008) that defines the quality of the shape’s representation in the shading mode. Default coefficient is 0.0008. 

@subsubsection occt_draw_4_3_20 vsetam

Syntax:                  
~~~~~
vsetam [shapename] mode
~~~~~ 

Activates selection mode for all selected or named shapes: 
* *0* for *shape* itself, 
* *1* (*vertices*), 
* *2* (*edges*), 
* *3* (*wires*), 
* *4* (*faces*), 
* *5* (*shells*),
* *6* (*solids*),
* *7* (*compounds*).
 
**Example:** 
~~~~~
vinit 
box b 10 10 10 
vdisplay b 
vfit 
vsetam b 2
~~~~~
 
@subsubsection occt_draw_4_3_21 vunsetam

Syntax:                  
~~~~~
vunsetam
~~~~~ 

Deactivates all selection modes for all shapes. 

@subsubsection occt_draw_4_3_22 vdump

Syntax:                  
~~~~~
vdump <filename>.{png|xwd|bmp}
~~~~~ 

Extracts the contents of the viewer window to a png, XWD or BMP file. 

@subsubsection occt_draw_4_3_23 vdir

Syntax:                  
~~~~~
vdir
~~~~~ 

Displays the list of displayed objects. 

@subsubsection occt_draw_4_3_24 vsub

Syntax:                  
~~~~~
vsub 0/1(on/off)[shapename]
~~~~~ 

Hilights/unhilights named or selected objects which are displayed at neutral state with subintensity color.
 
**Example:** 
~~~~~
vinit 
box b 10 10 10 
psphere s 20 
vdisplay b s 
vfit 
vsetdispmode 1 
vsub b 1
~~~~~ 

@subsubsection occt_draw_4_3_25 vardis

Syntax:                  
~~~~~
vardis
~~~~~ 

Displays active areas (for each activated sensitive entity, one or several 2D bounding boxes are displayed, depending on the implementation of a particular entity). 

@subsubsection occt_draw_4_3_26 varera

Syntax:                  
~~~~~
varera
~~~~~ 

Erases active areas. 

@subsubsection occt_draw_4_3_27 vsensdis

Syntax:                  
~~~~~
vsensdis
~~~~~ 

Displays active entities (sensitive entities of one of the standard types corresponding to active selection modes). 

Standard entity types are those defined in Select3D package: 
  * sensitive box
  * sensitive face
  * sensitive curve
  * sensitive segment
  * sensitive circle
  * sensitive point
  * sensitive triangulation
  * sensitive triangle
Custom (application-defined) sensitive entity types are not processed by this command. 

@subsubsection occt_draw_4_3_28 vsensera

Syntax:                  
~~~~~
vsensera
~~~~~ 

Erases active entities. 

@subsubsection occt_draw_4_3_29 vperf

Syntax:                  
~~~~~
vperf shapename 1/0 (Transformation/Loacation) 1/0 (Primitives sensibles ON/OFF)
~~~~~ 

Tests the animation of an object along a predefined trajectory. 

**Example:** 
~~~~~
vinit 
box b 10 10 10 
psphere s 20 
vdisplay b s 
vfit 
vsetdispmode 0 
vperf b 1 1
~~~~~
 
@subsubsection occt_draw_4_3_30 vr

Syntax:                  
~~~~~
vr filename
~~~~~ 

Reads shape from BREP-format file and displays it in the viewer. 

**Example:** 
~~~~~
vinit 
vr myshape.brep
~~~~~
 
@subsubsection occt_draw_4_3_31 vstate

Syntax:                  
~~~~~
vstate [name1] … [name n]
~~~~~ 

Makes a list of the status (**Displayed** or **Not Displayed**) of some selected or named objects. 


@subsection occt_draw_4_4 AIS viewer – object commands

@subsubsection occt_draw_4_4_1 vtrihedron

Syntax:                  
~~~~~
vtrihedron name [X0] [Y0] [Z0] [Zu] [Zv] [Zw] [Xu] [Xv] [Xw]
~~~~~ 

Creates a new *AIS_Trihedron* object. If no argument is set, the default trihedron (0XYZ) is created.
 
**Example:** 
~~~~~
vinit 
vtrihedron tr
~~~~~ 

@subsubsection occt_draw_4_4_2 vplanetri

Syntax:                  
~~~~~
vplanetri name
~~~~~ 

Creates a plane from a trihedron selection. 


@subsubsection occt_draw_4_4_3 vsize

Syntax:                  
~~~~~
vsize [name] [size]
~~~~~ 

Changes the size of a named or selected trihedron. If the name is not defined: it affects the selected trihedrons otherwise nothing is done. If the value is not defined, it is set to 100 by default.
 
**Example:** 
~~~~~
vinit 
vtrihedron tr1 
vtrihedron tr2 0 0 0 1 0 0 1 0 0 
vsize tr2 400
~~~~~ 

@subsubsection occt_draw_4_4_4 vaxis

Syntax:                  
~~~~~
vaxis name [Xa Ya Za Xb Yb Zb]
~~~~~ 

Creates an axis. If  the values are not defined, an axis is created by interactive selection of two vertices or one edge
 
**Example:** 
~~~~~
vinit 
vtrihedron tr 
vaxis axe1 0 0 0 1 0 0 
~~~~~

@subsubsection occt_draw_4_4_5 vaxispara

Syntax:                  
~~~~~
vaxispara nom
~~~~~ 

Creates an axis by interactive selection of an edge and a vertex. 

@subsubsection occt_draw_4_4_6 vaxisortho

Syntax:                  
~~~~~
vaxisotrho name
~~~~~ 

Creates an axis by interactive selection of an edge and a vertex. The axis will be orthogonal to the selected edge. 

@subsubsection occt_draw_4_4_7 vpoint

Syntax:                  
~~~~~
vpoint name [Xa Ya Za]
~~~~~ 

Creates a point from coordinates. If the values are not defined, a point is created by interactive selection of a vertice or an edge (in the center of the edge). 

**Example:** 
~~~~~
vinit 
vpoint p 0 0 0 
~~~~~

@subsubsection occt_draw_4_4_8 vplane

Syntax:                  
~~~~~
vplane name [AxisName] [PointName] 
vplane name [PointName] [PointName] [PointName] 
vplane name [PlaneName] [PointName]
~~~~~ 

Creates a plane from named or interactively selected entities.
 
**Example:** 
~~~~~
vinit 
vpoint p1 0 50 0 
vaxis axe1 0 0 0 0 0 1 
vtrihedron tr 
vplane plane1 axe1 p1 
~~~~~

@subsubsection occt_draw_4_4_9 vplanepara

Syntax:                  
~~~~~
vplanepara name
~~~~~ 

Creates a plane from interactively selected vertex and face. 

@subsubsection occt_draw_4_4_10 vplaneortho

Syntax:                  
~~~~~
vplaneortho name
~~~~~ 

Creates a plane from interactive selected face and coplanar edge. 

@subsubsection occt_draw_4_4_11 vline

Syntax:                  
~~~~~
vline name [PointName] [PointName] 
vline name [Xa Ya Za Xb Yb Zb]
~~~~~ 

Creates a line from coordinates, named or interactively selected vertices. 

**Example:** 
~~~~~
vinit 
vtrihedron tr 
vpoint p1 0 50 0 
vpoint p2 50 0 0 
vline line1 p1 p2 
vline line2 0 0 0 50 0 1 
~~~~~

@subsubsection occt_draw_4_4_12 vcircle

Syntax:      
~~~~~
vcircle name [PointName PointName PointName IsFilled] 
vcircle name [PlaneName PointName Radius IsFilled] 
~~~~~

Creates a circle from named or interactively selected entities.  Parameter IsFilled is defined as 0 or 1.
 
**Example:** 
~~~~~
vinit 
vtrihedron tr 
vpoint p1 0 50 0 
vpoint p2 50 0 0 
vpoint p3 0 0 0 
vcircle circle1 p1 p2 p3 1
~~~~~ 

@subsubsection occt_draw_4_4_13 vtri2d

Syntax:                  
~~~~~
vtri2d name
~~~~~ 

Creates a plane with a 2D trihedron from an interactively selected face. 

@subsubsection occt_draw_4_4_14 vselmode

Syntax:                  
~~~~~
vselmode [object] mode On/Off
~~~~~ 

Sets the selection mode for an object. If the object value is not defined, the selection mode is set for all displayed objects. 
Value *On* is defined as 1 and *Off* – as 0. 

**Example:** 
~~~~~
vinit 
vpoint p1 0 0 0 
vpoint p2 50 0 0 
vpoint p3 25 40 0 
vtriangle triangle1 p1 p2 p3 
~~~~~

@subsubsection occt_draw_4_4_15 vconnect, vconnectsh

Syntax:                  
~~~~~
vconnect name object Xo Yo Zo Xu Xv Xw Zu Zv Zw 
vconnectsh name shape Xo Yo Zo Xu Xv Xw Zu Zv Zw
~~~~~ 

Creates and displays an object with input location connected to a named entity. 
The difference between these two commands is that the object created by *vconnect* does not support the selection modes different from 0. 

**Example:** 
~~~~~
Vinitvinit 
vpoint p1 0 0 0 
vpoint p2 50 0 0 
vsegment segment p1 p2 
restore CrankArm.brep obj 
vdisplay obj 
vconnectsh new obj 100100100 1 0 0 0 0 1
~~~~~ 

@subsubsection occt_draw_4_4_16 vtriangle

Syntax:                  
~~~~~
vtriangle name PointName PointName PointName
~~~~~ 

Creates and displays a filled triangle from named points. 

**Example:** 
~~~~~
vinit 
vpoint p1 0 0 0 
vpoint p2 50 0 0 
vpoint p3 25 40 0 
vtriangle triangle1 p1 p2 p3
~~~~~ 

@subsubsection occt_draw_4_4_17 vsegment

Syntax:                  
~~~~~
vsegment name PointName PointName 
~~~~~

Creates and displays a segment from named points. 

**Example:** 
~~~~~
Vinit 
vpoint p1 0 0 0 
vpoint p2 50 0 0 
vsegment segment p1 p2 
~~~~~

@subsection occt_draw_4_5 AIS viewer – Mesh Visualization Service

**MeshVS** (Mesh Visualization Service) component provides flexible means of displaying meshes with associated pre- and post- processor data.

@subsubsection occt_draw_4_5_1 meshfromstl

Syntax:                  
~~~~~
meshfromstl meshname file
~~~~~ 

Creates a *MeshVS_Mesh* object based on STL file data. The object will be displayed immediately.
 
**Example:**
~~~~~ 
meshfromstl mesh myfile.stl
~~~~~ 

@subsubsection occt_draw_4_5_2 meshdispmode

Syntax:                  
~~~~~
meshdispmode meshname displaymode
~~~~~ 

Changes the display mode of object **meshname**. The **displaymode** is integer, which can be:
* *1* for *wireframe*, 
* *2* for *shading* mode, or
* *3* for *shrink* mode. 

**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshdispmode mesh 2
~~~~~ 

@subsubsection occt_draw_4_5_3 meshselmode

Syntax:                  
~~~~~
meshselmode meshname selectionmode
~~~~~ 

Changes the selection mode of object **meshname**. The *selectionmode* is integer OR-combination of mode flags. The basic flags are the following: 
* *1* – node selection;
* *2* – 0D elements (not supported in STL); 
* *4* – links (not supported in STL); 
* *8* – faces.
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshselmode mesh 1
~~~~~ 

@subsubsection occt_draw_4_5_4 meshshadcolor

Syntax:                  
~~~~~
meshshadcolor meshname red green blue
~~~~~ 

Changes the face interior color of object **meshname**. The *red*, *green** and *blue* are real values between *0* and *1*.
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshshadcolormode mesh 0.5 0.5 0.5
~~~~~ 

@subsubsection occt_draw_4_5_5 meshlinkcolor

Syntax:                  
~~~~~
meshlinkcolor meshname red green blue
~~~~~ 

Changes the color of face borders for object **meshname**. The *red*, *green* and *blue* are real values between *0* and *1*.
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshlinkcolormode mesh 0.5 0.5 0.5
~~~~~ 

@subsubsection occt_draw_4_5_6 meshmat

Syntax:                  
~~~~~
meshmat meshname material
~~~~~ 

Changes the material of object **meshname**.

*material* is represented with an integer value as follows (equivalent to enumeration *Graphic3d_NameOfMaterial*): 
* *0 – BRASS,* 
* *1 – BRONZE,* 
* *2 - COPPER,* 
* *3 - GOLD,* 
* *4 - PEWTER,* 
* *5 - PLASTER,* 
* *6 - PLASTIC,* 
* *7 - SILVER,* 
* *8 - STEEL,* 
* *9 - STONE,* 
* *10 - SHINY_PLASTIC,* 
* *11 - SATIN,*
* *12 - METALIZED,* 
* *13 - NEON_GNC,* 
* *14 - CHROME,*
* *15 - ALUMINIUM,*
* *16 - OBSIDIAN,* 
* *17 - NEON_PHC,* 
* *18 - JADE,*
* *19 - DEFAULT,* 
* *20 - UserDefined*
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshmat mesh JADE 
~~~~~

@subsubsection occt_draw_4_5_7 meshshrcoef

Syntax:                  
~~~~~
meshshrcoef meshname shrinkcoefficient
~~~~~ 

Changes the value of shrink coefficient used in the shrink mode. In the shrink mode the face is shown as a congruent part of a usual face, so that *shrinkcoefficient* controls the value of this part. The *shrinkcoefficient* is a positive real number.
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshshrcoef mesh 0.05
~~~~~ 

@subsubsection occt_draw_4_5_8 meshshow

Syntax:                  
~~~~~
meshshow meshname
~~~~~ 

Displays **meshname** in the viewer (if it is erased).
 
**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshshow mesh
~~~~~ 

@subsubsection occt_draw_4_5_9 meshhide

Syntax:                  
~~~~~
meshhide meshname
~~~~~ 

Hides **meshname** in the viewer. 

**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshhide mesh
~~~~~ 

@subsubsection occt_draw_4_5_10 meshhidesel

Syntax:                  
~~~~~
meshhidesel meshname
~~~~~ 

Hides only selected entities. The other part of **meshname** remains visible. 

@subsubsection occt_draw_4_5_11 meshshowsel

Syntax:                  
~~~~~
meshshowsel meshname
~~~~~ 

Shows only selected entities. The other part of **meshname** becomes invisible. 

@subsubsection occt_draw_4_5_12 meshshowall

Syntax:                  
~~~~~
meshshowall meshname
~~~~~ 

Changes the state of all entities to visible for **meshname**. 

@subsubsection occt_draw_4_5_13 meshdelete

Syntax:                  
~~~~~
meshdelete meshname
~~~~~ 

Deletes MeshVS_Mesh object **meshname**. 

**Example:** 
~~~~~
vinit 
meshfromstl mesh myfile.stl 
meshdelete mesh 
~~~~~

@section occt_draw_5 OCAF commands


This chapter contains a set of commands for Open CASCADE Technology Application Framework (OCAF). 


@subsection occt_draw_5_1 Application commands


@subsubsection occt_draw_5_1_1 NewDocument

Syntax:       
~~~~~
NewDocument docname [format]
~~~~~ 

Creates a new **docname** document with MDTV-Standard or described format. 

**Example:** 
~~~~~
# Create new document with default (MDTV-Standard) format 
NewDocument D 

# Create new document with BinOcaf format 
NewDocument D2 BinOcaf 
~~~~~

@subsubsection occt_draw_5_1_2 IsInSession

Syntax:       
~~~~~
IsInSession path
~~~~~ 

Returns *0*, if **path** document is managed by the application session, *1* – otherwise. 

**Example:** 
~~~~~
IsInSession /myPath/myFile.std 
~~~~~

@subsubsection occt_draw_5_1_3 ListDocuments

Syntax:       
~~~~~
ListDocuments
~~~~~ 

Makes a list of documents handled during the session of the application. 


@subsubsection occt_draw_5_1_4 Open

Syntax:       
~~~~~
Open path docname
~~~~~ 

Retrieves the document of file **docname** in the path **path**. Overwrites the document, if it is already in session. 

**Example:** 
~~~~~
Open /myPath/myFile.std D
~~~~~ 

@subsubsection occt_draw_5_1_5 Close

Syntax:       
~~~~~
Close docname
~~~~~ 

Closes **docname** document. The document is no longer handled by the applicative session. 

**Example:** 
~~~~~
Close D 
~~~~~

@subsubsection occt_draw_5_1_6 Save

Syntax:       
~~~~~
Save docname
~~~~~ 

Saves **docname** active document. 

**Example:** 
~~~~~
Save D 
~~~~~

@subsubsection occt_draw_5_1_7 SaveAs

Syntax:       
~~~~~
SaveAs docname path
~~~~~ 

Saves the active document in the file **docname** in the path **path**. Overwrites the file if it already exists. 

**Example:** 
~~~~~
SaveAs D /myPath/myFile.std
~~~~~ 

@subsection occt_draw_5_2       Basic commands

@subsubsection occt_draw_5_2_1  Label

Syntax:                 

~~~~~
Label docname entry
~~~~~

Creates the label expressed by <i><entry></i> if it does not exist.

Example
~~~~~
Label D 0:2
~~~~~

@subsubsection occt_draw_5_2_2  NewChild

Syntax:                 

~~~~~
NewChild docname [taggerlabel = Root label]
~~~~~
Finds (or creates) a *TagSource* attribute located at father label of <i><taggerlabel></i> and makes a new child label.

Example
~~~~~
# Create new child of root label
NewChild D

# Create new child of existing label
Label D 0:2
NewChild D 0:2
~~~~~

@subsubsection occt_draw_5_2_3  Children

Syntax:         
~~~~~
Children docname label
~~~~~
Returns the list of attributes of label.

Example
~~~~~
Children D 0:2
~~~~~

@subsubsection occt_draw_5_2_4  ForgetAll

Syntax:                 
~~~~~
ForgetAll docname label
~~~~~
Forgets all attributes of the label.

Example
~~~~~
ForgetAll D 0:2
~~~~~


@subsubsection occt_draw_5_3 Application commands

@subsubsection occt_draw_5_3_1  Main

Syntax:       
~~~~~
Main docname
~~~~~ 

Returns the main label of the framework. 

**Example:** 
~~~~~
Main D 
~~~~~

@subsubsection occt_draw_5_3_2  UndoLimit

Syntax:       
~~~~~
UndoLimit docname [value=0]
~~~~~ 


Sets the limit on the number of Undo Delta stored. **0** will disable Undo on the document. A negative *value* means that there is no limit. Note that by default Undo is disabled. Enabling it will take effect with the next call to *NewCommand*. Of course, this limit is the same for Redo 

**Example:** 
~~~~~
UndoLimit D 100 
~~~~~

@subsubsection occt_draw_5_3_3  Undo

Syntax:       
~~~~~
Undo docname [value=1]
~~~~~ 

Undoes **value** steps. 

**Example:** 
~~~~~
Undo D 
~~~~~

@subsubsection occt_draw_5_3_4  Redo

Syntax:       
~~~~~
Redo docname [value=1]
~~~~~ 

Redoes **value** steps.
 
**Example:** 
~~~~~
Redo D 
~~~~~

@subsubsection occt_draw_5_3_5  OpenCommand

Syntax:       
~~~~~
OpenCommand docname
~~~~~ 

Opens a new command transaction. 

**Example:**
~~~~~ 
OpenCommand D
~~~~~ 

@subsubsection occt_draw_5_3_6  CommitCommand

Syntax:       
~~~~~
CommitCommand docname
~~~~~ 

Commits the Command transaction. 

**Example:** 
~~~~~
CommitCommand D
~~~~~ 

@subsubsection occt_draw_5_3_7  NewCommand

Syntax:       
~~~~~
NewCommand docname
~~~~~ 

This is a short-cut for Commit and Open transaction. 

**Example:** 
~~~~~
NewCommand D 
~~~~~

@subsubsection occt_draw_5_3_8  AbortCommand

Syntax:       
~~~~~
AbortCommand docname
~~~~~ 

Aborts the Command transaction. 

**Example:** 
~~~~~
AbortCommand D 
~~~~~

@subsubsection occt_draw_5_3_9  Copy

Syntax:       
~~~~~
Copy docname entry Xdocname Xentry
~~~~~ 

Copies the contents of *entry* to *Xentry*. No links are registered. 

**Example:** 
~~~~~
Copy D1 0:2 D2 0:4 
~~~~~

@subsubsection occt_draw_5_3_10  UpdateLink

Syntax:       
~~~~~
UpdateLink docname [entry] 
~~~~~

Updates external reference set at *entry*. 

**Example:** 
~~~~~
UpdateLink D 
~~~~~

@subsubsection occt_draw_5_3_11  CopyWithLink

Syntax:       
~~~~~
CopyWithLink docname entry Xdocname Xentry
~~~~~ 

Aborts the Command transaction. 
Copies the content of *entry* to *Xentry*. The link is registered with an *Xlink* attribute at *Xentry*  label. 

**Example:** 
~~~~~
CopyWithLink D1 0:2 D2 0:4
~~~~~ 

@subsubsection occt_draw_5_3_12  UpdateXLinks

Syntax:       
~~~~~
UpdateXLinks docname entry
~~~~~ 

Sets modifications on labels impacted by external references to the *entry*. The *document* becomes invalid and must be recomputed 

**Example:** 
~~~~~
UpdateXLinks D 0:2 
~~~~~

@subsubsection occt_draw_5_3_13  DumpDocument

Syntax:       
~~~~~
DumpDocument docname
~~~~~ 

Displays parameters of *docname* document. 

**Example:** 
~~~~~
DumpDocument D 
~~~~~


@subsection occt_draw_5_4  Data Framework commands


@subsubsection occt_draw_5_4_1  MakeDF

Syntax:       
~~~~~
MakeDF dfname
~~~~~ 

Creates a new data framework. 

**Example:** 
~~~~~
MakeDF D 
~~~~~

@subsubsection occt_draw_5_4_2  ClearDF

Syntax:       
~~~~~
ClearDF dfname
~~~~~ 

Clears a data framework. 

**Example:** 
~~~~~
ClearDF D 
~~~~~

@subsubsection occt_draw_5_4_3  CopyDF

Syntax:       
~~~~~
CopyDF dfname1 entry1 [dfname2] entry2
~~~~~ 

Copies a data framework. 

**Example:** 
~~~~~
CopyDF D 0:2 0:4 
~~~~~

@subsubsection occt_draw_5_4_4  CopyLabel

Syntax:       
~~~~~
CopyLabel dfname fromlabel tolablel
~~~~~ 

Copies a label. 

**Example:** 
~~~~~
CopyLabel D1 0:2 0:4 
~~~~~

@subsubsection occt_draw_5_4_5  MiniDumpDF

Syntax:       
~~~~~
MiniDumpDF dfname
~~~~~ 

Makes a mini-dump of a data framework. 

**Example:** 
~~~~~
MiniDumpDF D 
~~~~~

@subsubsection occt_draw_5_4_6  XDumpDF

Syntax:       
~~~~~
XDumpDF dfname
~~~~~ 

Makes an extended dump of a data framework. 

**Example:** 
~~~~~
XDumpDF D
~~~~~ 

@subsection occt_draw_5_5  General attributes commands


@subsubsection occt_draw_5_5_1  SetInteger

Syntax:       
~~~~~
SetInteger dfname entry value
~~~~~ 

Finds or creates an Integer attribute at *entry* label and sets *value*. 

**Example:** 
~~~~~
SetInteger D 0:2 100 
~~~~~

@subsubsection occt_draw_5_5_2  GetInteger

Syntax:       
~~~~~
GetInteger dfname entry [drawname]
~~~~~ 

Gets a value of an Integer attribute at *entry* label and sets it to *drawname* variable, if it is defined. 

**Example:** 
~~~~~
GetInteger D 0:2 Int1 
~~~~~

@subsubsection occt_draw_5_5_3  SetReal

Syntax:       
~~~~~
SetReal dfname entry value
~~~~~ 

Finds or creates a Real attribute at *entry* label and sets *value*. 

**Example:** 
~~~~~
SetReal D 0:2 100. 
~~~~~

@subsubsection occt_draw_5_5_4  GetReal

Syntax:       
~~~~~
GetReal dfname entry [drawname]
~~~~~ 

Gets a value of a Real attribute at *entry* label and sets it to *drawname* variable, if it is defined. 

**Example:** 
~~~~~
GetReal D 0:2 Real1 
~~~~~

@subsubsection occt_draw_5_5_5  SetIntArray

Syntax:       
~~~~~
SetIntArray dfname entry lower upper value1 value2 … 
~~~~~

Finds or creates an IntegerArray attribute at *entry* label with lower and upper bounds and sets **value1*, *value2*... 

**Example:** 
~~~~~
SetIntArray D 0:2 1 4 100 200 300 400
~~~~~ 

@subsubsection occt_draw_5_5_6  GetIntArray

Syntax:       
~~~~~
GetIntArray dfname entry
~~~~~ 

Gets a value of an *IntegerArray* attribute at *entry* label. 

**Example:** 
~~~~~
GetIntArray D 0:2
~~~~~ 

@subsubsection occt_draw_5_5_7  SetRealArray

Syntax:       
~~~~~
SetRealArray dfname entry lower upper value1 value2 …
~~~~~ 

Finds or creates a RealArray attribute at *entry* label with lower and upper bounds and sets *value1*, *value2*… 

**Example:** 
~~~~~
GetRealArray D 0:2 1 4 100. 200. 300. 400. 
~~~~~

@subsubsection occt_draw_5_5_8  GetRealArray

Syntax:       
~~~~~
GetRealArray dfname entry
~~~~~ 

Gets a value of a RealArray attribute at *entry* label. 

**Example:** 
~~~~~
GetRealArray D 0:2 
~~~~~

@subsubsection occt_draw_5_5_9  SetComment

Syntax:       
~~~~~
SetComment dfname entry value
~~~~~ 

Finds or creates a Comment attribute at *entry* label and sets *value*. 

**Example:** 
~~~~~
SetComment D 0:2 "My comment"
~~~~~ 

@subsubsection occt_draw_5_5_10  GetComment

Syntax:       
~~~~~
GetComment dfname entry
~~~~~ 

Gets a value of a Comment attribute at *entry* label. 

**Example:** 
~~~~~
GetComment D 0:2
~~~~~ 

@subsubsection occt_draw_5_5_11  SetExtStringArray

Syntax:       
~~~~~
SetExtStringArray dfname entry lower upper value1 value2 …
~~~~~ 

Finds or creates an *ExtStringArray* attribute at *entry* label with lower and upper bounds and sets *value1*, *value2*… 

**Example:** 
~~~~~
SetExtStringArray D 0:2 1 3 *string1* *string2* *string3*
~~~~~ 

@subsubsection occt_draw_5_5_12  GetExtStringArray

Syntax:       
~~~~~
GetExtStringArray dfname entry
~~~~~ 

Gets a value of an ExtStringArray attribute at *entry* label. 

**Example:** 
~~~~~
GetExtStringArray D 0:2 
~~~~~

@subsubsection occt_draw_5_5_13  SetName

Syntax:       
~~~~~
SetName dfname entry value 
~~~~~

Finds or creates a Name attribute at *entry* label and sets *value*. 

**Example:** 
~~~~~
SetName D 0:2 *My name* 
~~~~~

@subsubsection occt_draw_5_5_14  GetName

Syntax:       
~~~~~
GetName dfname entry 
~~~~~

Gets a value of a Name attribute at *entry* label. 

**Example:** 
~~~~~
GetName D 0:2 
~~~~~

@subsubsection occt_draw_5_5_15  SetReference

Syntax:       
~~~~~
SetReference dfname entry reference 
~~~~~

Creates a Reference attribute at *entry* label and sets *reference*. 

**Example:** 
~~~~~
SetReference D 0:2 0:4 
~~~~~

@subsubsection occt_draw_5_5_16  GetReference

Syntax:       
~~~~~
GetReference dfname entry 
~~~~~

Gets a value of a Reference attribute at *entry* label. 

**Example:** 
~~~~~
GetReference D 0:2 
~~~~~

@subsubsection occt_draw_5_5_17  SetUAttribute

Syntax:       
~~~~~
SetUAttribute dfname entry localGUID 
~~~~~

Creates a UAttribute attribute at *entry* label with *localGUID*. 

**Example:** 
~~~~~
set localGUID "c73bd076-22ee-11d2-acde-080009dc4422" 
SetUAttribute D 0:2 ${localGUID} 
~~~~~

@subsubsection occt_draw_5_5_18  GetUAttribute

Syntax:       
~~~~~
GetUAttribute dfname entry loacalGUID 
~~~~~

Finds a *UAttribute* at *entry* label with *localGUID*. 

**Example:** 
~~~~~
set localGUID "c73bd076-22ee-11d2-acde-080009dc4422" 
GetUAttribute D 0:2 ${localGUID} 
~~~~~

@subsubsection occt_draw_5_5_19  SetFunction

Syntax:       
~~~~~
SetFunction dfname entry ID failure 
~~~~~

Finds or creates a *Function* attribute at *entry* label with driver ID and *failure* index. 

**Example:** 
~~~~~
set ID "c73bd076-22ee-11d2-acde-080009dc4422" 
SetFunction D 0:2 ${ID} 1 
~~~~~

@subsubsection occt_draw_5_5_20  GetFunction

Syntax:       
~~~~~
GetFunction dfname entry ID failure 
~~~~~

Finds a Function attribute at *entry* label and sets driver ID to *ID* variable and failure index to *failure* variable. 

**Example:** 
~~~~~
GetFunction D 0:2 ID failure 
~~~~~

@subsubsection occt_draw_5_5_21  NewShape

Syntax:       
~~~~~
NewShape dfname entry [shape] 
~~~~~

Finds or creates a Shape attribute at *entry* label. Creates or updates the associated *NamedShape* attribute by *shape* if *shape* is defined. 

**Example:** 
~~~~~
box b 10 10 10 
NewShape D 0:2 b 
~~~~~

@subsubsection occt_draw_5_5_22  SetShape

Syntax:       
~~~~~
SetShape dfname entry shape 
~~~~~

Creates or updates a *NamedShape* attribute at *entry* label by *shape*. 

**Example:** 
~~~~~
box b 10 10 10 
SetShape D 0:2 b 
~~~~~

@subsubsection occt_draw_5_5_23  GetShape

Syntax:       
~~~~~
GetShape2 dfname entry shape 
~~~~~

Sets a shape from NamedShape attribute associated with *entry* label to *shape* draw variable. 

**Example:** 
~~~~~
GetShape2 D 0:2 b 
~~~~~

@subsection occt_draw_5_6  Geometric attributes commands


@subsubsection occt_draw_5_6_1  SetPoint

Syntax:       
~~~~~
SetPoint dfname entry point
~~~~~ 

Finds or creates a Point attribute at *entry* label and sets *point* as generated in the associated *NamedShape* attribute. 

**Example:** 
~~~~~
point p 10 10 10 
SetPoint D 0:2 p 
~~~~~

@subsubsection occt_draw_5_6_2  GetPoint

Syntax:       
~~~~~
GetPoint dfname entry [drawname] 
~~~~~

Gets a vertex from *NamedShape* attribute at *entry* label and sets it to *drawname* variable, if it is defined. 

**Example:** 
~~~~~
GetPoint D 0:2 p 
~~~~~

@subsubsection occt_draw_5_6_3  SetAxis

Syntax:       
~~~~~
SetAxis dfname entry axis 
~~~~~

Finds or creates an Axis attribute at *entry* label and sets *axis* as generated in the associated *NamedShape* attribute. 

**Example:** 
~~~~~
line l 10 20 30 100 200 300 
SetAxis D 0:2 l 
~~~~~

@subsubsection occt_draw_5_6_4  GetAxis

Syntax:       
~~~~~
GetAxis dfname entry [drawname] 
~~~~~

Gets a line from *NamedShape* attribute at *entry* label and sets it to *drawname* variable, if it is defined. 

**Example:** 
~~~~~
GetAxis D 0:2 l 
~~~~~

@subsubsection occt_draw_5_6_5  SetPlane

Syntax:       
~~~~~
SetPlane dfname entry plane 
~~~~~

Finds or creates a Plane attribute at *entry* label and sets *plane* as generated in the associated *NamedShape* attribute. 

**Example:** 
~~~~~
plane pl 10 20 30 –1 0 0 
SetPlane D 0:2 pl 
~~~~~

@subsubsection occt_draw_5_6_6  GetPlane

Syntax:       
~~~~~
GetPlane dfname entry [drawname] 
~~~~~

Gets a plane from *NamedShape* attribute at *entry* label and sets it to *drawname* variable, if it is defined. 

**Example:** 
~~~~~
GetPlane D 0:2 pl 
~~~~~

@subsubsection occt_draw_5_6_7  SetGeometry

Syntax:       
~~~~~
SetGeometry dfname entry [type] [shape] 
~~~~~

Creates a Geometry attribute at *entry* label and sets *type* and *shape* as generated in the associated *NamedShape* attribute if they are defined. *type* must be one of the following: *any, pnt, lin, cir, ell, spl, pln, cyl*. 

**Example:** 
~~~~~
point p 10 10 10 
SetGeometry D 0:2 pnt p 
~~~~~

@subsubsection occt_draw_5_6_8  GetGeometryType

Syntax:       
~~~~~
GetGeometryType dfname entry
~~~~~ 

Gets a geometry type from Geometry attribute at *entry* label. 

**Example:** 
~~~~~
GetGeometryType D 0:2 
~~~~~

@subsubsection occt_draw_5_6_9  SetConstraint

Syntax:       
~~~~~
SetConstraint dfname entry keyword geometrie [geometrie …] 
SetConstraint dfname entry "plane" geometrie 
SetConstraint dfname entry "value" value
~~~~~  

1. Creates a Constraint attribute at *entry* label and sets *keyword* constraint between geometry(ies). 
*keyword* must be one of the following: 
*rad, dia, minr, majr, tan, par, perp, concentric, equal, dist, angle, eqrad, symm, midp, eqdist, fix, rigid,* or *from, axis, mate, alignf, aligna, axesa, facesa, round, offset* 
2. Sets plane for the existing constraint. 
3. Sets value for the existing constraint. 

**Example:** 
~~~~~
SetConstraint D 0:2 "value" 5 
~~~~~

@subsubsection occt_draw_5_6_10  GetConstraint

Syntax:       
~~~~~
GetConstraint dfname entry
~~~~~ 

Dumps a Constraint attribute at *entry* label 

**Example:** 
~~~~~
GetConstraint D 0:2 
~~~~~

@subsubsection occt_draw_5_6_11  SetVariable

Syntax:       
~~~~~
SetVariable dfname entry isconstant(0/1) units 
~~~~~

Creates a Variable attribute at *entry* label and sets *isconstant* flag and *units* as a string. 

**Example:** 
~~~~~
SetVariable D 0:2 1 "mm" 
~~~~~

@subsubsection occt_draw_5_6_12  GetVariable

Syntax:       
~~~~~
GetVariable dfname entry isconstant units 
~~~~~

Gets an *isconstant* flag and units of a Variable attribute at *entry* label. 

**Example:** 
~~~~~
GetVariable D 0:2 isconstant units 
puts "IsConstant=${isconstant}" 
puts "Units=${units}" 
~~~~~

@subsection occt_draw_5_7  Tree attributes commands


@subsubsection occt_draw_5_7_1  RootNode

Syntax:       
~~~~~
RootNode dfname treenodeentry [ID]
~~~~~ 

Returns the ultimate father of *TreeNode* attribute identified by its *treenodeentry* and its *ID* (or default ID, if *ID* is not defined). 


@subsubsection occt_draw_5_7_2  SetNode

Syntax:       
~~~~~
SetNode dfname treenodeentry [ID]
~~~~~ 

Creates a *TreeNode* attribute on the *treenodeentry* label with its tree *ID* (or assigns a default ID, if the *ID* is not defined). 


@subsubsection occt_draw_5_7_3  AppendNode

Syntax:       
~~~~~
AppendNode dfname fatherentry childentry [fatherID]
~~~~~ 


Inserts a *TreeNode* attribute with its tree *fatherID* (or default ID, if *fatherID* is not defined) on *childentry* as last child of *fatherentry*. 




@subsubsection occt_draw_5_7_4  PrependNode

Syntax:       
~~~~~
PrependNode dfname fatherentry childentry [fatherID]
~~~~~ 


Inserts a *TreeNode* attribute with its tree *fatherID* (or default ID, if *fatherID* is not defined) on *childentry* as first child of *fatherentry*. 


@subsubsection occt_draw_5_7_5  InsertNodeBefore

Syntax:       
~~~~~
InsertNodeBefore dfname treenodeentry beforetreenode [ID]
~~~~~ 

Inserts a *TreeNode* attribute with tree *ID* (or default ID, if *ID* is not defined) *beforetreenode* before *treenodeentry*. 


@subsubsection occt_draw_5_7_6  InsertNodeAfter

Syntax:       
~~~~~
InsertNodeAfter dfname treenodeentry aftertreenode [ID]
~~~~~ 

Inserts a *TreeNode* attribute with tree *ID* (or default ID, if *ID* is not defined) *aftertreenode* after *treenodeentry*. 


@subsubsection occt_draw_5_7_7  DetachNode

Syntax:       
~~~~~
DetachNode dfname treenodeentry [ID]
~~~~~ 

Removes a *TreeNode* attribute with tree *ID* (or default ID, if *ID* is not defined) from *treenodeentry*. 


@subsubsection occt_draw_5_7_8  ChildNodeIterate

Syntax:       
~~~~~
ChildNodeIterate dfname treenodeentry alllevels(0/1) [ID]
~~~~~ 


Iterates on the tree of *TreeNode* attributes with tree *ID* (or default ID, if *ID* is not defined). If *alllevels* is set to *1* it explores not only the first, but all the sub Step levels.
 
**Example:** 
~~~~~
Label D 0:2 
Label D 0:3 
Label D 0:4 
Label D 0:5 
Label D 0:6 
Label D 0:7 
Label D 0:8 
Label D 0:9 

# Set root node 
SetNode D 0:2 

AppendNode D 0:2 0:4 
AppendNode D 0:2 0:5 
PrependNode D 0:4 0:3 
PrependNode D 0:4 0:8 
PrependNode D 0:4 0:9 

InsertNodeBefore D 0:5 0:6 
InsertNodeAfter D 0:4 0:7 

DetachNode D 0:8 


# List all levels 
ChildNodeIterate D 0:2 1 

==0:4 
==0:9 
==0:3 
==0:7 
==0:6 
==0:5 


# List only first levels 
ChildNodeIterate D 0:2 1 

==0:4 
==0:7 
==0:6 
==0:5 
~~~~~

@subsubsection occt_draw_5_7_9  InitChildNodeIterator

Syntax:       
~~~~~
InitChildNodeIterator dfname treenodeentry alllevels(0/1) [ID]
~~~~~ 


Initializes the iteration on the tree of *TreeNode* attributes with tree *ID* (or default ID, if *ID* is not defined). If *alllevels* is set to *1* it explores not only the first, but also all sub Step levels. 

**Example:** 
~~~~~
InitChildNodeIterate D 0:5 1 
set aChildNumber 0 
for {set i 1} {$i  100} {incr i} { 
    if {[ChildNodeMore] == *TRUE*} { 
        puts *Tree node = [ChildNodeValue]* 
        incr aChildNumber 
        ChildNodeNext 
    } 
} 
puts "aChildNumber=$aChildNumber"
~~~~~ 

@subsubsection occt_draw_5_7_10  ChildNodeMore

Syntax:       
~~~~~
ChildNodeMore
~~~~~ 

Returns TRUE if there is a current item in the iteration. 


@subsubsection occt_draw_5_7_11  ChildNodeNext

Syntax:       
~~~~~
ChildNodeNext
~~~~~ 

Moves to the next Item. 


@subsubsection occt_draw_5_7_12  ChildNodeValue

Syntax:       
~~~~~
ChildNodeValue
~~~~~ 

Returns the current treenode of *ChildNodeIterator*. 


@subsubsection occt_draw_5_7_13  ChildNodeNextBrother

Syntax:       
~~~~~
ChildNodeNextBrother
~~~~~ 

Moves to the next *Brother*. If there is none, goes up. This method is interesting only with *allLevels* behavior. 


@subsection occt_draw_5_8   Standard presentation commands


@subsubsection occt_draw_5_8_1  AISInitViewer

Syntax:       
~~~~~
AISInitViewer docname
~~~~~ 

Creates and sets *AISViewer* attribute at root label, creates AIS viewer window. 

**Example:** 
~~~~~
AISInitViewer D 
~~~~~

@subsubsection occt_draw_5_8_2  AISRepaint

Syntax:       
~~~~~
AISRepaint docname 
~~~~~

Updates the AIS viewer window. 

**Example:** 
~~~~~
AISRepaint D 
~~~~~

@subsubsection occt_draw_5_8_3  AISDisplay

Syntax:       
~~~~~
AISDisplay docname entry [not_update] 
~~~~~

Displays a presantation of *AISobject* from *entry* label in AIS viewer. If *not_update* is not defined then *AISobject* is recomputed and all visualization settings are applied. 

**Example:** 
~~~~~
AISDisplay D 0:5 
~~~~~

@subsubsection occt_draw_5_8_4  AISUpdate

Syntax:       
~~~~~
AISUpdate docname entry 
~~~~~

Recomputes a presentation of *AISobject* from *entry* label and applies the visualization setting in AIS viewer. 

**Example:** 
~~~~~
AISUpdate D 0:5 
~~~~~

@subsubsection occt_draw_5_8_5  AISErase

Syntax:       
~~~~~
AISErase docname entry 
~~~~~

Erases *AISobject* of *entry* label in AIS viewer. 

**Example:** 
~~~~~
AISErase D 0:5 
~~~~~

@subsubsection occt_draw_5_8_6  AISRemove

Syntax:       
~~~~~
AISRemove docname entry 
~~~~~

Erases *AISobject* of *entry* label in AIS viewer, then *AISobject* is removed from *AIS_InteractiveContext*. 

**Example:** 
~~~~~
AISRemove D 0:5 
~~~~~

@subsubsection occt_draw_5_8_7  AISSet

Syntax:       
~~~~~
AISSet docname entry ID 
~~~~~

Creates *AISPresentation* attribute at *entry* label and sets as driver ID. ID must be one of the following: *A* (*axis*), *C* (*constraint*), *NS* (*namedshape*), *G* (*geometry*), *PL* (*plane*), *PT* (*point*). 

**Example:** 
~~~~~
AISSet D 0:5 NS 
~~~~~

@subsubsection occt_draw_5_8_8  AISDriver

Syntax:       
~~~~~
AISDriver docname entry [ID] 
~~~~~

Returns DriverGUID stored in *AISPresentation* attribute of an *entry* label or sets a new one. ID must be one of the following: *A* (*axis*), *C* (*constraint*), *NS* (*namedshape*), *G* (*geometry*), *PL* (*plane*), *PT* (*point*). 

**Example:** 
~~~~~
# Get Driver GUID 
AISDriver D 0:5 
~~~~~

@subsubsection occt_draw_5_8_9  AISUnset

Syntax:       
~~~~~
AISUnset docname entry 
~~~~~

Deletes *AISPresentation* attribute (if it exists) of an *entry* label. 

**Example:** 
~~~~~
AISUnset D 0:5 
~~~~~

@subsubsection occt_draw_5_8_10  AISTransparency

Syntax:       
~~~~~
AISTransparency docname entry [transparency] 
~~~~~

Sets (if *transparency* is defined) or gets the value of transparency for *AISPresentation* attribute of an *entry* label. 

**Example:** 
~~~~~
AISTransparency D 0:5 0.5 
~~~~~

@subsubsection occt_draw_5_8_11  AISHasOwnTransparency

Syntax:       
~~~~~
AISHasOwnTransparency docname entry 
~~~~~

Tests *AISPresentation* attribute of an *entry* label by own transparency. 

**Example:** 
~~~~~
AISHasOwnTransparency D 0:5 
~~~~~

@subsubsection occt_draw_5_8_12  AISMaterial

Syntax:       
~~~~~
AISMaterial docname entry [material] 
~~~~~

Sets (if *material* is defined) or gets the value of transparency for *AISPresentation* attribute of an *entry* label. *material* is integer from 0 to 20 (see <a href="#occt_draw_4_5_6">meshmat</a> command). 

**Example:** 
~~~~~
AISMaterial D 0:5 5 
~~~~~

@subsubsection occt_draw_5_8_13  AISHasOwnMaterial

Syntax:       
~~~~~
AISHasOwnMaterial docname entry 
~~~~~

Tests *AISPresentation* attribute of an *entry* label by own material. 

**Example:** 
~~~~~
AISHasOwnMaterial D 0:5 
~~~~~

@subsubsection occt_draw_5_8_14  AISColor

Syntax:       
~~~~~
AISColor docname entry [color] 
~~~~~

Sets (if *color* is defined) or gets value of color for *AISPresentation* attribute of an *entry* label. *color* is integer from 0 to 516 (see color names in *vsetcolor*). 

**Example:** 
~~~~~
AISColor D 0:5 25 
~~~~~

@subsubsection occt_draw_5_8_15  AISHasOwnColor

Syntax:       
~~~~~
AISHasOwnColor docname entry 
~~~~~

Tests *AISPresentation* attribute of an *entry* label by own color. 

**Example:** 
~~~~~
AISHasOwnColor D 0:5 
~~~~~

@section occt_draw_6 Geometry commands

@subsection occt_draw_6_1 Overview

Draw provides a set of commands to test geometry libraries. These commands are found in the TGEOMETRY executable, or in any Draw executable which includes *GeometryTest* commands. 

In the context of Geometry, Draw includes the following types of variable: 

  * 2d and 3d points
  * The 2d curve, which corresponds to *Curve* in *Geom2d*.
  * The 3d curve and surface, which correspond to *Curve* and *Surface* in <a href="user_guides__modeling_data.html#occt_modat_1">Geom package</a>.
  
Draw geometric variables never share data; the *copy* command will always make a complete copy of the content of the variable. 

The following topics are covered in the nine sections of this chapter: 

  * **Curve creation** deals with the various types of curves and how to create them.
  * **Surface creation** deals with the different types of surfaces and how to create them.
  * **Curve and surface modification** deals with the commands used to modify the definition of curves and surfaces, most of which concern modifications to bezier and bspline curves.
  * **Geometric transformations** covers translation, rotation, mirror image and point scaling transformations.
  * **Curve and Surface Analysis** deals with the commands used to compute points, derivatives and curvatures.
  * **Intersections** presents intersections of surfaces and curves.
  * **Approximations** deals with creating curves and surfaces from a set of points.
  * **Constraints** concerns construction of 2d circles and lines by constraints such as tangency.
  * **Display** describes commands to control the display of curves and surfaces.

Where possible, the commands have been made broad in application, i.e. they apply to 2d curves, 3d curves and surfaces. For instance, the *circle* command may create a 2d or a 3d circle depending on the number of arguments given. 

Likewise, the *translate* command will process points, curves or surfaces, depending on argument type. You may not always find the specific command you are looking for in the section where you expect it to be. In that case, look in another section. The *trim* command, for example, is described in the surface section. It can, nonetheless, be used with curves as well. 

@subsection occt_draw_6_2  Curve creation

This section deals with both points and curves. Types of curves are: 

  * Analytical curves such as lines, circles, ellipses, parabolas, and hyperbolas.
  * Polar curves such as bezier curves and bspline curves.
  * Trimmed curves and offset curves made from other curves with the *trim* and *offset* commands. Because they are used on both curves and surfaces, the *trim* and *offset* commands are described in the *surface creation* section.
  * NURBS can be created from other curves using *convert* in the *Surface Creation* section.
  * Curves can be created from the isoparametric lines of surfaces by the *uiso* and *viso* commands.
  * 3d curves can be created from 2d curves and vice versa using the *to3d* and *to2d* commands. The *project* command computes a 2d curve on a 3d surface.

Curves are displayed with an arrow showing the last parameter. 


@subsubsection occt_draw_6_2_1 point

Syntax:      
~~~~~
point name x y [z] 
~~~~~
  
Creates a 2d or 3d point, depending on the number of arguments. 

**Example:**
~~~~~
# 2d point 
point p1 1 2 

# 3d point 
point p2 10 20 -5 
~~~~~
  
@subsubsection occt_draw_6_2_2  line

Syntax:      
~~~~~
line name x y [z] dx dy [dz]
~~~~~ 

  
Creates a 2d or 3d line. *x y z* are the coordinates of the line’s point of origin; *dx, dy, dz* give the direction vector. 

A 2d line will be represented as *x y dx dy*, and a 3d line as *x y z dx dy dz* . A line is parameterized along its length starting from the point of origin along the direction vector. The direction vector is normalized and must not be null. Lines are infinite, even though their representation is not. 

**Example:** 
~~~~~
# a 2d line at 45 degrees of the X axis 
line l 2 0 1 1 

# a 3d line through the point 10 0 0 and parallel to Z 
line l 10 0 0 0 0 1 
~~~~~

@subsubsection occt_draw_6_2_3  circle

Syntax:      
~~~~~
circle name x y [z [dx dy dz]] [ux uy [uz]] radius
~~~~~ 

Creates a 2d or a 3d circle. 

In 2d, *x, y* are the coordinates of the center and *ux, uy* define the vector towards the point of origin of the parameters. By default, this direction is (1,0). The X Axis of the local coordinate system defines the origin of the parameters of the circle. Use another vector than the x axis to change the origin of parameters. 

In 3d, *x, y, z* are the coordinates of the center; *dx, dy, dz* give the vector normal to the plane of the circle. By default, this vector is (0,0,1) i.e. the Z axis (it must not be null). *ux, uy, uz* is the direction of the origin; if not given, a default direction will be computed. This vector must neither be null nor parallel to *dx, dy, dz*. 

The circle is parameterized by the angle in [0,2*pi] starting from the origin and. Note that the specification of origin direction and plane is the same for all analytical curves and surfaces. 

**Example:** 
~~~~~
# A 2d circle of radius 5 centered at 10,-2 
circle c1 10 -2 5 

# another 2d circle with a user defined origin 
# the point of parameter 0 on this circle will be 
# 1+sqrt(2),1+sqrt(2) 
circle c2 1 1 1 1 2 

# a 3d circle, center 10 20 -5, axis Z, radius 17 
circle c3 10 20 -5 17 

# same 3d circle with axis Y 
circle c4 10 20 -5 0 1 0 17 

# full 3d circle, axis X, origin on Z 
circle c5 10 20 -5 1 0 0 0 0 1 17 
~~~~~

@subsubsection occt_draw_6_2_4  ellipse

Syntax: 
~~~~~
ellipse name x y [z [dx dy dz]] [ux uy [uz]] firstradius secondradius 
~~~~~

Creates a 2d or 3d ellipse. In a 2d ellipse, the first two arguments define the center; in a 3d ellipse, the first three. The axis system is given by *firstradius*, the major radius, and *secondradius*, the minor radius. The parameter range of the ellipse is [0,2.*pi] starting from the X axis and going towards the Y axis. The Draw ellipse is parameterized by an angle: 

~~~~~
P(u) = O + firstradius*cos(u)*Xdir + secondradius*sin(u)*Ydir 
~~~~~
where: 

  * P is the point of parameter *u*,
  * *O, Xdir* and *Ydir* are respectively the origin, *X Direction* and *Y Direction* of its local coordinate system.
 
**Example:**
~~~~~
# default 2d ellipse 
ellipse e1 10 5 20 10 

# 2d ellipse at angle 60 degree 
ellipse e2 0 0 1 2 30 5 

# 3d ellipse, in the XY plane 
ellipse e3 0 0 0 25 5 

# 3d ellipse in the X,Z plane with axis 1, 0 ,1 
ellipse e4 0 0 0 0 1 0 1 0 1 25 5 
~~~~~

@subsubsection occt_draw_6_2_5  hyperbola

Syntax:      
~~~~~
hyperbola name x y [z [dx dy dz]] [ux uy [uz]] firstradius secondradius
~~~~~ 

Creates a 2d or 3d conic. The first arguments define the center. The axis system is given by *firstradius*, the major radius, and *secondradius*, the minor radius. Note that the hyperbola has only one branch, that in the X direction. 

The Draw hyperbola is parameterized as follows: 
~~~~~
P(U) = O + firstradius*Cosh(U)*XDir + secondradius*Sinh(U)*YDir 
~~~~~
where: 

  * *P* is the point of parameter *U*,
  * *O, XDir* and *YDir* are respectively the origin, *X Direction* and *YDirection* of its local coordinate system. 

**Example:** 
~~~~~
# default 2d hyperbola, with asymptotes 1,1 -1,1 
hyperbola h1 0 0 30 30 

# 2d hyperbola at angle 60 degrees 
hyperbola h2 0 0 1 2 20 20 

# 3d hyperbola, in the XY plane 
hyperbola h3 0 0 0 50 50 
~~~~~

@subsubsection occt_draw_6_2_6  parabola

Syntax:      
~~~~~
parabola name x y [z [dx dy dz]] [ux uy [uz]] FocalLength 
~~~~~

Creates a 2d or 3d parabola. in the axis system defined by the first arguments. The origin is the apex of the parabola. 

The *Geom_Parabola* is parameterized as follows: 

~~~~~
P(u) = O + u*u/(4.*F)*XDir + u*YDir 
~~~~~

where: 
  * *P* is the point of parameter *u*,
  * *O, XDir* and *YDir* are respectively the origin, *X Direction* and *Y Direction* of its local coordinate system,
  * *F* is the focal length of the parabola.

**Example:** 
~~~~~
# 2d parabola 
parabola p1 0 0 50 

# 2d parabola with convexity +Y 
parabola p2 0 0 0 1 50 

# 3d parabola in the Y-Z plane, convexity +Z 
parabola p3 0 0 0 1 0 0 0 0 1 50 
~~~~~

@subsubsection occt_draw_6_2_7  beziercurve, dbeziercurve

Syntax:      
~~~~~
beziercurve name nbpole pole, [weight] 
2dbeziercurve name nbpole pole, [weight]
~~~~~ 

Creates a 3d rational or non-rational Bezier curve. Give the number of poles (control points,) and the coordinates of the poles *(x1 y1 z1 [w1] x2 y2 z2 [w2])*. The degree will be *nbpoles-1*. To create a rational curve, give weights with the poles. You must give weights for all poles or for none. If the weights of all the poles are equal, the curve is polynomial, and therefore non-rational. 

**Example:** 
~~~~~
# a rational 2d bezier curve (arc of circle) 
2dbeziercurve ci 3 0 0 1 10 0 sqrt(2.)/2. 10 10 1 

# a 3d bezier curve, not rational 
beziercurve cc 4 0 0 0 10 0 0 10 0 10 10 10 10 
~~~~~

@subsubsection occt_draw_6_2_8  bsplinecurve, dbsplinecurve, pbsplinecurve, dpbsplinecurve

Syntax:      
~~~~~
bsplinecurve name degree nbknots knot, umult pole, weight 2dbsplinecurve name degree nbknots knot, umult pole, weight pbsplinecurve name degree nbknots knot, umult pole, weight(periodic) 

2dpbsplinecurve name degree nbknots knot, umult pole, weight (periodic) 
~~~~~

Creates 2d or 3d bspline curves; the **pbsplinecurve** and **2dpbsplinecurve** commands create periodic bspline curves. 

A bspline curve is defined by its degree, its periodic or non-periodic nature, a table of knots and a table of poles (i.e. control points). Consequently, specify the degree, the number of knots, and for each knot, the multiplicity, for each pole, the weight. In the syntax above, the commas link the adjacent arguments which they fall between: knot and multiplicities, pole and weight. 

The table of knots is an increasing sequence of reals without repetition. 
Multiplicities must be lower or equal to the degree of the curve. For non-periodic curves, the first and last multiplicities can be equal to degree+1. For a periodic curve, the first and last multiplicities must be equal. 

The poles must be given with their weights, use weights of 1 for a non rational curve, the number of poles must be: 

  * For a non periodic curve: Sum of multiplicities - degree + 1
  * For a periodic curve: Sum of multiplicities - last multiplicity

**Example:** 
~~~~~
# a bspline curve with 4 poles and 3 knots 
bsplinecurve bc 2 3 0 3 1 1 2 3 \ 
10 0 7 1 7 0 7 1 3 0 8 1 0 0 7 1 
# a 2d periodic circle (parameter from 0 to 2*pi !!) 
dset h sqrt(3)/2 
2dpbsplinecurve c 2 \ 
4 0 2 pi/1.5 2 pi/0.75 2 2*pi 2 \ 
0 -h/3 1 \ 
0.5 -h/3 0.5 \ 
0.25 h/6 1 \ 
0 2*h/3 0.5 \ 
-0.25 h/6 1 \ 
-0.5 -h/3 0.5 \ 
0 -h/3 1 
~~~~~

**Note** that you can create the **NURBS** subset of bspline curves and surfaces by trimming analytical curves and surfaces and executing the command *convert*. 


@subsubsection occt_draw_6_2_9  uiso, viso

Syntax:      
~~~~~
uiso name surface u 
viso name surface u 
~~~~~

Creates a U or V isoparametric curve from a surface. 

**Example:** 
~~~~~
# create a cylinder and extract iso curves 

cylinder c 10 
uiso c1 c pi/6 
viso c2 c 
~~~~~

**Note** that this cannot be done from offset surfaces.


@subsubsection occt_draw_6_2_10  tod, tod

Syntax:      
~~~~~
to3d name curve2d [plane] 
to2d name curve3d [plane] 
~~~~~

Create respectively a 3d curve from a 2d curve and a 2d curve from a 3d curve. The transformation uses a planar surface to define the XY plane in 3d (by default this plane is the default OXYplane). **to3d** always gives a correct result, but as **to2d** is not a projection, it may surprise you. It is always correct if the curve is planar and parallel to the plane of projection. The points defining the curve are projected on the plane. A circle, however, will remain a circle and will not be changed to an ellipse. 

**Example:** 
~~~~~
# the following commands 
circle c 0 0 5 
plane p -2 1 0 1 2 3 
to3d c c p 

# will create the same circle as 
circle c -2 1 0 1 2 3 5 
~~~~~

See also: **project** 


@subsubsection occt_draw_6_2_11  project

Syntax:      
~~~~~
project name curve3d surface 
~~~~~

Computes a 2d curve in the parametric space of a surface corresponding to a 3d curve. This can only be used on analytical surfaces. 

If we, for example, intersect a cylinder and a plane and project the resulting ellipse on the cylinder, this will create a 2d sinusoid-like bspline. 

~~~~~
cylinder c 5 
plane p 0 0 0 0 1 1 
intersect i c p 
project i2d i c 
~~~~~

@subsection occt_draw_6_3  Surface creation

The following types of surfaces exist: 
  * Analytical surfaces: plane, cylinder, cone, sphere, torus;
  * Polar surfaces: bezier surfaces, bspline surfaces;
  * Trimmed and Offset surfaces;
  * Surfaces produced by Revolution and Extrusion, created from curves with the *revsurf* and *extsurf*;
  * NURBS surfaces.

Surfaces are displayed with isoparametric lines. To show the parameterization, a small parametric line with a length 1/10 of V is displayed at 1/10 of U. 

@subsubsection occt_draw_6_3_1  plane

Syntax:      
~~~~~
plane name [x y z [dx dy dz [ux uy uz]]]
~~~~~ 

Creates an infinite plane. 

A plane is the same as a 3d coordinate system, *x,y,z* is the origin, *dx, dy, dz* is the Z direction and *ux, uy, uz* is the X direction. 

The plane is perpendicular to Z and X is the U parameter. *dx,dy,dz* and *ux,uy,uz* must not be null or collinear. *ux,uy,uz* will be modified to be orthogonal to *dx,dy,dz*. 

There are default values for the coordinate system. If no arguments are given, the global system (0,0,0), (0,0,1), (1,0,0). If only the origin is given, the axes are those given by default(0,0,1), (1,0,0). If the origin and the Z axis are given, the X axis is generated perpendicular to the Z axis. 

Note that this definition will be used for all analytical surfaces. 

**Example:** 
~~~~~
# a plane through the point 10,0,0 perpendicular to X 
# with U direction on Y 
plane p1 10 0 0 1 0 0 0 1 0 

# an horixontal plane with origin 10, -20, -5 
plane p2 10 -20 -5 
~~~~~

@subsubsection occt_draw_6_3_2  cylinder

Syntax:      
~~~~~
cylinder name [x y z [dx dy dz [ux uy uz]]] radius 
~~~~~

A cylinder is defined by a coordinate system, and a radius. The surface generated is an infinite cylinder with the Z axis as the axis. The U parameter is the angle starting from X going in the Y direction. 

**Example:** 
~~~~~
# a cylinder on the default Z axis, radius 10 
cylinder c1 10 

# a cylinder, also along the Z axis but with origin 5, 
10, -3 
cylinder c2 5 10 -3 10 

# a cylinder through the origin and on a diagonal 
# with longitude pi/3 and latitude pi/4 (euler angles) 
dset lo pi/3. la pi/4. 
cylinder c3 0 0 0 cos(la)*cos(lo) cos(la)*sin(lo) 
sin(la) 10 
~~~~~

@subsubsection occt_draw_6_3_3  cone

Syntax:      
~~~~~
cone name [x y z [dx dy dz [ux uy uz]]] semi-angle radius 
~~~~~
Creates a cone in the infinite coordinate system along the Z-axis. The radius is that of the circle at the intersection of the cone and the XY plane. The semi-angle is the angle formed by the cone relative to the axis; it should be between –90 and 90. If the radius is 0, the vertex is the origin. 

**Example:** 
~~~~~
# a cone at 45 degrees at the origin on Z 
cone c1 45 0 

# a cone on axis Z with radius r1 at z1 and r2 at z2 
cone c2 0 0 z1 180.*atan2(r2-r1,z2-z1)/pi r1 
~~~~~

@subsubsection occt_draw_6_3_4  sphere

Syntax:      
~~~~~
sphere name [x y z [dx dy dz [ux uy uz]]] radius 
~~~~~

Creates a sphere in the local coordinate system defined in the **plane** command. The sphere is centered at the origin. 

To parameterize the sphere, *u* is the angle from X to Y, between 0 and 2*pi. *v* is the angle in the half-circle at angle *u* in the plane containing the Z axis. *v* is between -pi/2 and pi/2. The poles are the points Z = +/- radius; their parameters are u,+/-pi/2 for any u in 0,2*pi. 

**Example:**
~~~~~ 
# a sphere at the origin 
sphere s1 10 
# a sphere at 10 10 10, with poles on the axis 1,1,1 
sphere s2 10 10 10 1 1 1 10 
~~~~~

@subsubsection occt_draw_6_3_5  torus

Syntax:      
~~~~~
torus name [x y z [dx dy dz [ux uy uz]]] major minor
~~~~~ 

Creates a torus in the local coordinate system with the given major and minor radii. *Z* is the axis for the major radius. The major radius may be lower in value than the minor radius. 

To parameterize a torus, *u* is the angle from X to Y; *v* is the angle in the plane at angle *u* from the XY plane to Z. *u* and *v* are in 0,2*pi. 

**Example:** 
~~~~~
# a torus at the origin 
torus t1 20 5 

# a torus in another coordinate system 
torus t2 10 5 -2 2 1 0 20 5 
~~~~~


@subsubsection occt_draw_6_3_6  beziersurf

Syntax:      
~~~~~
beziersurf name nbupoles nbvolpes pole, [weight] 
~~~~~

Use this command to create a bezier surface, rational or non-rational. First give the numbers of poles in the u and v directions. 

Then give the poles in the following order: *pole(1, 1), pole(nbupoles, 1), pole(1, nbvpoles)* and *pole(nbupoles, nbvpoles)*. 

Weights may be omitted, but if you give one weight you must give all of them. 

**Example:** 
~~~~~
# a non-rational degree 2,3 surface 
beziersurf s 3 4 \ 
0 0 0 10 0 5 20 0 0 \ 
0 10 2 10 10 3 20 10 2 \ 
0 20 10 10 20 20 20 20 10 \ 
0 30 0 10 30 0 20 30 0 
~~~~~

@subsubsection occt_draw_6_3_7   bsplinesurf, upbsplinesurf, vpbsplinesurf, uvpbsplinesurf

Syntax:     
~~~~~
bsplinesurf name udegree nbuknots uknot umult ... nbvknot vknot 
vmult ... x y z w ... 
upbsplinesurf ... 
vpbsplinesurf ... 
uvpbsplinesurf ... 
~~~~~

* **bsplinesurf** generates bspline surfaces;
* **upbsplinesurf** creates a bspline surface periodic in u; 
* **vpbsplinesurf** creates one periodic in v; 
* **uvpbsplinesurf** creates one periodic in uv. 

The syntax is similar to the *bsplinecurve* command. First give the degree in u and the knots in u with their multiplicities, then do the same in v. The poles follow. The number of poles is the product of the number in u and the number in v. 

See *bsplinecurve* to compute the number of poles, the poles are first given in U as in the *beziersurf* command. You must give weights if the surface is rational. 

**Example:** 
~~~~~
# create a bspline surface of degree 1 2 
# with two knots in U and three in V 
bsplinesurf s \ 
1 2 0 2 1 2 \ 
2 3 0 3 1 1 2 3 \ 
0 0 0 1 10 0 5 1 \ 
0 10 2 1 10 10 3 1 \ 
0 20 10 1 10 20 20 1 \ 
0 30 0 1 10 30 0 1 
~~~~~


@subsubsection occt_draw_6_3_8  trim, trimu, trimv

Syntax:      
~~~~~
trim newname name [u1 u2 [v1 v2]] 
trimu newname name 
trimv newname name 
~~~~~

The **trim** commands create trimmed curves or trimmed surfaces. Note that trimmed curves and surfaces are classes of the *Geom* package. 
* *trim* creates either a new trimmed curve from a curve or a new trimmed surface in u and v from a surface.
* *trimu* creates a u-trimmed surface, 
* *trimv* creates a v-trimmed surface. 

After an initial trim, a second execution with no parameters given recreates the basis curve. The curves can be either 2d or 3d. If the trimming parameters decrease and if the curve or surface is not periodic, the direction is reversed. 

**Note** that a trimmed curve or surface contains a copy of the basis geometry: modifying that will not modify the trimmed geometry. Trimming trimmed geometry will not create multiple levels of trimming. The basis geometry will be used. 

**Example:** 
~~~~~
# create a 3d circle 
circle c 0 0 0 10 

# trim it, use the same variable, the original is 
deleted 
trim c c 0 pi/2 

# the original can be recovered! 
trim orc c 

# trim again 
trim c c pi/4 pi/2 

# the original is not the trimmed curve but the basis 
trim orc c 

# as the circle is periodic, the two following commands 
are identical 
trim cc c pi/2 0 
trim cc c pi/2 2*pi 

# trim an infinite cylinder 
cylinder cy 10 
trimv cy cy 0 50 
~~~~~

@subsubsection occt_draw_6_3_9  offset

Syntax:      
~~~~~
offset name basename distance [dx dy dz]
~~~~~ 

Creates offset curves or surfaces at a given distance from a basis curve or surface. Offset curves and surfaces are classes from the *Geom *package. 

The curve can be a 2d or a 3d curve. To compute the offsets for a 3d curve, you must also give a vector *dx,dy,dz*. For a planar curve, this vector is usually the normal to the plane containing the curve. 

The offset curve or surface copies the basic geometry, which can be modified later. 

**Example:** 
~~~~~
# graphic demonstration that the outline of a torus 
# is the offset of an ellipse 
smallview +X+Y 
dset angle pi/6 
torus t 0 0 0 0 cos(angle) sin(angle) 50 20 
fit 
ellipse e 0 0 0 50 50*sin(angle) 
# note that the distance can be negative 
offset l1 e 20 0 0 1 
~~~~~

@subsubsection occt_draw_6_3_10  revsurf

Syntax:      
~~~~~
revsurf name curvename x y z dx dy dz
~~~~~ 

Creates a surface of revolution from a 3d curve. 

A surface of revolution or revolved surface is obtained by rotating a curve (called the *meridian*) through a complete revolution about an axis (referred to as the *axis of revolution*). The curve and the axis must be in the same plane (the *reference plane* of the surface). Give the point of origin x,y,z and the vector dx,dy,dz to define the axis of revolution. 

To parameterize a surface of revolution: u is the angle of rotation around the axis. Its origin is given by the position of the meridian on the surface. v is the parameter of the meridian. 

**Example:** 
~~~~~
# another way of creating a torus like surface 
circle c 50 0 0 20 
revsurf s c 0 0 0 0 1 0 
~~~~~

@subsubsection occt_draw_6_3*11  extsurf

Syntax:      
~~~~~
extsurf newname curvename dx dy dz 
~~~~~

Creates a surface of linear extrusion from a 3d curve. The basis curve is swept in a given direction,the *direction of extrusion* defined by a vector. 

In the syntax, *dx,dy,dz* gives the direction of extrusion. 

To parameterize a surface of extrusion: *u* is the parameter along the extruded curve; the *v* parameter is along the direction of extrusion. 

**Example:** 
~~~~~
# an elliptic cylinder 
ellipse e 0 0 0 10 5 
extsurf s e 0 0 1 
# to make it finite 
trimv s s 0 10 
~~~~~

@subsubsection occt_draw_6_3_12  convert

Syntax:      
~~~~~
convert newname name 
~~~~~

Creates a 2d or 3d NURBS curve or a NURBS surface from any 2d curve, 3d curve or surface. In other words, conics, beziers and bsplines are turned into NURBS. Offsets are not processed.
 
**Example:** 
~~~~~
# turn a 2d arc of a circle into a 2d NURBS 
circle c 0 0 5 
trim c c 0 pi/3 
convert c1 c 

# an easy way to make a planar bspline surface 
plane p 
trim p p -1 1 -1 1 
convert p1 p 
~~~~~

**Note** that offset curves and surfaces are not processed by this command.

@subsection occt_draw_6_4  Curve and surface modifications

Draw provides commands to modify curves and surfaces, some of them are general, others restricted to bezier curves or bsplines. 

General modifications: 

  * Reversing the parametrization: **reverse**, **ureverse**, **vreverse**

Modifications for both bezier curves and bsplines: 

  * Exchanging U and V on a surface: **exchuv**
  * Segmentation: **segment**, **segsur**
  * Increasing the degree: **incdeg**, **incudeg**, **incvdeg**
  * Moving poles: **cmovep**, **movep**, **movecolp**, **moverowp**

Modifications for bezier curves: 

  * Adding and removing poles: **insertpole**, **rempole**, **remcolpole**, **remrowpole**

Modifications for bspline: 

  * Inserting and removing knots: **insertknot**, **remknot**, **insertuknot**, **remuknot**, **insetvknot**, **remvknot**
  * Modifying periodic curves and surfaces: **setperiodic**, **setnotperiodic**, **setorigin**, **setuperiodic**, **setunotperiodic**, **setuorigin**, **setvperiodic**, **setvnotperiodic**, **setvorigin**



@subsubsection occt_draw_6_4_1  reverse, ureverse, vreverse


Syntax:            
~~~~~
reverse curvename 
ureverse surfacename 
vreverse surfacename 
~~~~~

The **reverse** command reverses the parameterization and inverses the orientation of a 2d or 3d curve. Note that the geometry is modified. To keep the curve or the surface, you must copy it before modification. 

**ureverse** or **vreverse** reverse the u or v parameter of a surface. Note that the new parameters of the curve may change according to the type of curve. For instance, they will change sign on a line or stay 0,1 on a bezier. 

Reversing a parameter on an analytical surface may create an indirect coordinate system. 

**Example:** 
~~~~~
# reverse a trimmed 2d circle 
circle c 0 0 5 
trim c c pi/4 pi/2 
reverse c 

# dumping c will show that it is now trimmed between 
# 3*pi/2 and 7*pi/4 i.e. 2*pi-pi/2 and 2*pi-pi/4 
~~~~~

@subsubsection occt_draw_6_4_2  exchuv

Syntax:                 
~~~~~
exchuv surfacename 
~~~~~