Unity RenderTexture

• RenderTexture 当作为 Camera.targetTexture 时，在某些安卓手机或模拟器无法显示
  Camera.clearFlags 必须为 CameraClearFlags.Depth ，CameraClearFlags.Nothing 时会不显示

• RenderTexture转Texture2D

/// <summary>  RenderTexture转Texture2D </summary>
private Texture2D RenderTexture2Texture2D(RenderTexture rt){
	RenderTexture preRT=RenderTexture.active;
	RenderTexture.active=rt;
	Texture2D tex=new Texture2D(rt.width,rt.height,TextureFormat.ARGB32,false);
	tex.ReadPixels(new Rect(0,0,rt.width,rt.height),0,0);
	tex.Apply();
	RenderTexture.active=preRT;
	return tex;
}