//Graphic3d_TextureUnit_MetallicRoughness = Graphic3d_TextureUnit_2, //!< metalness+roughness of the material
//Graphic3d_TextureUnit_Emissive = Graphic3d_TextureUnit_3, //!< emissive map controls the color and intensity of the light being emitted by the material
//Graphic3d_TextureUnit_Occlusion = Graphic3d_TextureUnit_4, //!< occlusion map indicating areas of indirect lighting
+
+ Graphic3d_TextureUnit_EnvMap = Graphic3d_TextureUnit_0 //!< environment cubemap for background
};
enum
{