Graphics.Blit

Parameters

Description

Copies source texture into destination render texture with a shader.

This is mostly used for implementing post-processing effects.

Blit sets dest as the render target, sets source _MainTex property on the material, and draws a full-screen quad.

If dest is null, the screen backbuffer is used as the blit destination, except if the main camera is currently set to render to a RenderTexture (that is Camera.main has a non-null targetTexture property). In that case the blit uses the render target of the main camera as destination. In order to ensure that the blit is actually done to the screen backbuffer, make sure to set /Camera.main.targetTexture/ to null before calling Blit.

Note that if you want to use depth or stencil buffer that is part of the source (Render)texture, you'll have to do equivalent of Blit functionality manually - i.e. Graphics.SetRenderTarget with destination color buffer and source depth buffer, setup orthographic projection (GL.LoadOrtho), setup material pass (Material.SetPass) and draw a quad (GL.Begin).

Note that in Linear color space, it is important to have the correct sRGB<->Linear color conversion state set. Depending on what was rendered previously, the current state might not be the one you expect. You should consider setting GL.sRGBWrite as you need it before doing Blit or any other manual rendering.

Note that a call to Blit with source and dest set to the same RenderTexture may result in undefined behaviour. A better approach is to either use Custom Render Textures with double buffering, or use two RenderTextures and alternate between them to implement double buffering manually.

See Also: Graphics.BlitMultiTap, Post-processing effects.

using UnityEngine;

public class Example : MonoBehaviour
{ // Copies aTexture to rTex and displays it in all cameras.

    Texture aTexture;
    RenderTexture rTex;

    void Start()
    {
        if (!aTexture || !rTex)
        {
            Debug.LogError("A texture or a render texture are missing, assign them.");
        }
    }

    void Update()
    {
        Graphics.Blit(aTexture, rTex);
    }
}