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

In OpenGL this matches glMultiTexCoord for all texture units or glTexCoord when no multi-texturing is available. On other graphics APIs the same functionality is emulated.

The Z component is used only when:
1. You access a cubemap (which you access with a vector coordinate, hence x,y & z).
2. You do "projective texturing", where the X & Y coordinates are divided by Z to get the final coordinate. This would be mostly useful for water reflections and similar things.

This function can only be called between GL.Begin and GL.End functions.

	// Draws a Quad in the middle of the screen and
	// Adds the material's Texture to it.
	var mat : Material;
	function OnPostRender() {
		if (!mat) {
			Debug.LogError("Please Assign a material on the inspector");
			return;
		}
		GL.PushMatrix();
		mat.SetPass(1);
		GL.Color(Color(1,1,1,1));
		GL.LoadOrtho();
		GL.Begin(GL.QUADS);
		GL.TexCoord(Vector3(0,0,0));
		GL.Vertex3(0.25,0.25,0);
		GL.TexCoord(Vector3(0,1,0));
		GL.Vertex3(0.25,0.75,0);
		GL.TexCoord(Vector3(1,1,0));
		GL.Vertex3(0.75,0.75,0);
		GL.TexCoord(Vector3(1,0,0));
		GL.Vertex3(0.75,0.25,0);
		GL.End();
		GL.PopMatrix();
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Material mat;
    void OnPostRender() {
        if (!mat) {
            Debug.LogError("Please Assign a material on the inspector");
            return;
        }
        GL.PushMatrix();
        mat.SetPass(1);
        GL.Color(new Color(1, 1, 1, 1));
        GL.LoadOrtho();
        GL.Begin(GL.QUADS);
        GL.TexCoord(new Vector3(0, 0, 0));
        GL.Vertex3(0.25F, 0.25F, 0);
        GL.TexCoord(new Vector3(0, 1, 0));
        GL.Vertex3(0.25F, 0.75F, 0);
        GL.TexCoord(new Vector3(1, 1, 0));
        GL.Vertex3(0.75F, 0.75F, 0);
        GL.TexCoord(new Vector3(1, 0, 0));
        GL.Vertex3(0.75F, 0.25F, 0);
        GL.End();
        GL.PopMatrix();
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public mat as Material

	def OnPostRender() as void:
		if not mat:
			Debug.LogError('Please Assign a material on the inspector')
			return
		GL.PushMatrix()
		mat.SetPass(1)
		GL.Color(Color(1, 1, 1, 1))
		GL.LoadOrtho()
		GL.Begin(GL.QUADS)
		GL.TexCoord(Vector3(0, 0, 0))
		GL.Vertex3(0.25F, 0.25F, 0)
		GL.TexCoord(Vector3(0, 1, 0))
		GL.Vertex3(0.25F, 0.75F, 0)
		GL.TexCoord(Vector3(1, 1, 0))
		GL.Vertex3(0.75F, 0.75F, 0)
		GL.TexCoord(Vector3(1, 0, 0))
		GL.Vertex3(0.75F, 0.25F, 0)
		GL.End()
		GL.PopMatrix()