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Scripting > Runtime Classes > GL
GL Class

Low-level graphics library.

Use this class to manipulate active transformation matrices, issue rendering commands similar to OpenGL's immediate mode and do other low-level graphics tasks. Note that in almost all cases using Graphics.DrawMesh is more efficient than using immediate mode drawing.

GL immediate drawing functions use whatever is the "current material" set up right now. The material controls how the rendering is done (blending, textures, etc.), so unless you explicitly set it to something before using GL draw functions, the material can happen to be anything. Also, if you call any other drawing commands from inside GL drawing code, they can set material to something else, so make sure it's under control as well.

GL drawing commands execute immediately. That means if you call them in Update(), they will be executed before the camera is rendered (and the camera will most likely clear the screen, making the GL drawing not visible). The usual place to call GL drawing is most often in OnPostRender() from a script attached to a camera:

static var lineMaterial : Material;

static function CreateLineMaterial()
{
if( !lineMaterial ) {
lineMaterial = new Material( "Shader \"Lines/Colored Blended\" {" +
"SubShader { Pass { " +
" Blend SrcAlpha OneMinusSrcAlpha " +
" ZWrite Off Cull Off Fog { Mode Off } " +
" BindChannels {" +
" Bind \"vertex\", vertex Bind \"color\", color }" +
"} } }" );
lineMaterial.hideFlags = HideFlags.HideAndDontSave;
lineMaterial.shader.hideFlags = HideFlags.HideAndDontSave;
}
}

function OnPostRender()
{
CreateLineMaterial();
// set the current material
lineMaterial.SetPass( 0 );
GL.Begin( GL.LINES );
GL.Color( Color(1,1,1,0.5) );
GL.Vertex3( 0, 0, 0 );
GL.Vertex3( 1, 0, 0 );
GL.Vertex3( 0, 1, 0 );
GL.Vertex3( 1, 1, 0 );
GL.Color( Color(0,0,0,0.5) );
GL.Vertex3( 0, 0, 0 );
GL.Vertex3( 0, 1, 0 );
GL.Vertex3( 1, 0, 0 );
GL.Vertex3( 1, 1, 0 );
GL.End();
}

This class is only available in Unity Pro.

Class Variables
TRIANGLES

Mode for Begin: draw triangles.

TRIANGLE_STRIP

Mode for Begin: draw triangle strip.

QUADS

Mode for Begin: draw quads.

LINES

Mode for Begin: draw lines.

modelview

The current modelview matrix.

Class Functions
Vertex3

Submit a vertex.

Vertex

Submit a vertex.

Color

Sets current vertex color.

TexCoord

Sets current texture coordinate (v.x,v.y,v.z) for all texture units.

TexCoord2

Sets current texture coordinate (x,y) for all texture units.

TexCoord3

Sets current texture coordinate (x,y,z) for all texture units.

MultiTexCoord2

Sets current texture coordinate (x,y) for the actual texture unit.

MultiTexCoord3

Sets current texture coordinate (x,y,z) to the actual texture unit.

MultiTexCoord

Sets current texture coordinate (v.x,v.y,v.z) to the actual texture unit.

Begin

Begin drawing 3D primitives.

End

End drawing 3D primitives.

LoadOrtho

Helper function to set up an ortho perspective transform.

LoadPixelMatrix

Setup a matrix for pixel-correct rendering.

Viewport

Set the rendering viewport.

LoadProjectionMatrix

Load an arbitrary matrix to the current projection matrix.

LoadIdentity

Load the identity matrix to the current modelview matrix.

MultMatrix

Multiplies the current modelview matrix with the one specified.

PushMatrix

Saves both projection and modelview matrices to the matrix stack.

PopMatrix

Restores both projection and modelview matrices off the top of the matrix stack.

SetRevertBackfacing

Select whether to invert the backface culling (true) or not (false).

Clear

Clear the current render buffer.