Material.SetPass

Parameters

Returns

bool If false is returned, no rendering should be done.

Description

Activate the given pass for rendering.

Pass indices start from zero and go up to (but not including) passCount.

This is mostly used in direct drawing code using GL class. For example, Image Effects use materials for implementing screen post-processing. For each pass in the material they activate the pass and draw a fullscreen quad.

If SetPass returns false, you should not render anything. This is typically the case for special pass types that aren't meant for rendering, like GrabPass.

#pragma strict
// A script that when attached to the camera, makes the resulting
// colors inverted. See its effect in play mode.
private var mat: Material;
// Will be called from camera after regular rendering is done.
public function OnPostRender() {
	if (!mat) {
		// a blend mode that inverts destination colors.			
		var shader: var = Shader.Find("Hidden/Internal-Colored");
		mat = new Material(shader);
		mat.hideFlags = HideFlags.HideAndDontSave;
		// Set blend mode to invert destination colors.
		mat.SetInt("_SrcBlend", intUnityEngine.Rendering.BlendMode.OneMinusDstColor);
		mat.SetInt("_DstBlend", intUnityEngine.Rendering.BlendMode.Zero);
		// Turn off backface culling, depth writes, depth test.
		mat.SetInt("_Cull", intUnityEngine.Rendering.CullMode.Off);
		mat.SetInt("_ZWrite", 0);
		mat.SetInt("_ZTest", intUnityEngine.Rendering.CompareFunction.Always);
	}
	GL.PushMatrix();
	GL.LoadOrtho();
	// activate the first shader pass (in this case we know it is the only pass)
	mat.SetPass(0);
	// draw a quad over whole screen
	GL.Begin(GL.QUADS);
	GL.Vertex3(0, 0, 0);
	GL.Vertex3(1, 0, 0);
	GL.Vertex3(1, 1, 0);
	GL.Vertex3(0, 1, 0);
	GL.End();
	GL.PopMatrix();
}

using UnityEngine;

// A script that when attached to the camera, makes the resulting
// colors inverted. See its effect in play mode.
public class ExampleClass : MonoBehaviour
{
    private Material mat;

    // Will be called from camera after regular rendering is done.
    public void OnPostRender ()
    {
        if (!mat)
        {
            // Unity has a built-in shader that is useful for drawing
            // simple colored things. In this case, we just want to use
            // a blend mode that inverts destination colors.			
            var shader = Shader.Find ("Hidden/Internal-Colored");
            mat = new Material (shader);
            mat.hideFlags = HideFlags.HideAndDontSave;
            // Set blend mode to invert destination colors.
            mat.SetInt ("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusDstColor);
            mat.SetInt ("_DstBlend", (int)UnityEngine.Rendering.BlendMode.Zero);
            // Turn off backface culling, depth writes, depth test.
            mat.SetInt ("_Cull", (int)UnityEngine.Rendering.CullMode.Off);
            mat.SetInt ("_ZWrite", 0);
            mat.SetInt ("_ZTest", (int)UnityEngine.Rendering.CompareFunction.Always);
        }

        GL.PushMatrix ();
        GL.LoadOrtho ();

        // activate the first shader pass (in this case we know it is the only pass)
        mat.SetPass (0);
        // draw a quad over whole screen
        GL.Begin (GL.QUADS);
        GL.Vertex3 (0, 0, 0);
        GL.Vertex3 (1, 0, 0);
        GL.Vertex3 (1, 1, 0);
        GL.Vertex3 (0, 1, 0);
        GL.End ();

        GL.PopMatrix ();
    }
}

See Also: passCount property, GL class, ShaderLab documentation.