Version: 5.4
public void ReadPixels (Rect source, int destX, int destY, bool recalculateMipMaps= true);

Parameters

source Rectangular region of the view to read from. Pixels are read from current render target.
destX Horizontal pixel position in the texture to place the pixels that are read.
destY Vertical pixel position in the texture to place the pixels that are read.
recalculateMipMaps Should the texture's mipmaps be recalculated after reading?

Description

Read pixels from screen into the saved texture data.

This will copy a rectangular pixel area from the currently active RenderTexture or the view (specified by the source parameter) into the position defined by destX and destY. Both coordinates use pixel space - (0,0) is lower left.

If recalculateMipMaps is set to true, the mip maps of the texture will also be updated. If recalculateMipMaps is set to false, you must call Apply to recalculate them.

This function works on ARGB32 and RGB24 texture formats, when render target is of a similar format too (e.g. usual 32 or 16 bit render texture). Reading from a HDR render target (ARGBFloat or ARGBHalf render texture formats) into HDR texture formats (RGBAFloat or RGBAHalf) is supported too.

The texture also has to have Read/Write Enabled flag set in the import settings.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public bool grab; public Renderer display; void OnPostRender() { if (grab) { Texture2D tex = new Texture2D(128, 128); tex.ReadPixels(new Rect(0, 0, 128, 128), 0, 0); tex.Apply(); display.material.mainTexture = tex; grab = false; } } }

See Also: EncodeToPNG.