| colorFormat | Render Texture format. | 
Creates the sourceRenderTexture and destinationRenderTexture.
                  The render textures are created at a resolution matching the current PaintContext.pixelRect, using the specified RenderTextureFormat.
                  This function is called internally by TerrainPaintUtility.BeginPaintHeightmap, TerrainPaintUtility.BeginPaintTexture and TerrainPaintUtility.CollectNormals.
                  See Also: PaintContext.destinationRenderTexture, PaintContext.sourceRenderTexture