MonoBehaviour.OnPostRender()

Description

OnPostRender is called after a camera finished rendering the scene.

This function is called only if the script is attached to the camera and is enabled. OnPostRender can be a co-routine, simply use the yield statement in the function.

OnPostRender is called after the camera renders all its objects. If you want to do something after all cameras and GUI is rendered, use WaitForEndOfFrame coroutine.

See Also: OnPreRender, WaitForEndOfFrame.

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();
    }
}