Legacy Documentation: Version 2018.1 (Go to current version)
  • C#
  • JS

Script language

Select your preferred scripting language. All code snippets will be displayed in this language.


Suggest a change


Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.


Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.



public static method Begin(mode: int): void;
public static void Begin(int mode);


modePrimitives to draw: can be TRIANGLES, TRIANGLE_STRIP, QUADS or LINES.


Begin drawing 3D primitives.

In OpenGL this matches glBegin; on other graphics APIs the same functionality is emulated. Between GL.Begin and GL.End it is valid to call GL.Vertex, GL.Color, GL.TexCoord and other immediate mode drawing functions.

You should be careful about culling when drawing primitives yourself. The culling rules may be different depending on which graphics API the game is running. In most cases the safest way is to use Cull Off command in the shader.

See Also: GL.End.

    // Draws a Triangle, a Quad and a line
    // with different colors

var mat : Material; function OnPostRender() { if (!mat) { Debug.LogError("Please Assign a material on the inspector"); return; } GL.PushMatrix(); mat.SetPass(0); GL.LoadOrtho(); GL.Begin(GL.TRIANGLES); // Triangle GL.Color(Color(1,1,1,1)); GL.Vertex3(0.50,0.25,0); GL.Vertex3(0.25,0.25,0); GL.Vertex3(0.375,0.5,0); GL.End(); GL.Begin(GL.QUADS); // Quad GL.Color(Color(0.5,0.5,0.5,1)); GL.Vertex3(0.5,0.5,0); GL.Vertex3(0.5,0.75,0); GL.Vertex3(0.75,0.75,0); GL.Vertex3(0.75,0.5,0); GL.End(); GL.Begin(GL.LINES); // Line GL.Color(Color(0,0,0,1)); GL.Vertex3(0,0,0); GL.Vertex3(0.75,0.75,0); GL.End(); GL.PopMatrix(); }
no example available in C#

Did you find this page useful? Please give it a rating: