void RenderToBRDFMap()
{
if (File.Exists(mOutputPath + "brdfLUT.png"))
{
return;
}
RenderTexture mBRDFMap = new RenderTexture(512, 512, 0, RenderTextureFormat.ARGBFloat);
if (mRenderToBRDFMaterial == null)
{
Shader shader = Shader.Find("liangairan/pbr/brdf_lut");
mRenderToBRDFMaterial = new Material(shader);
}
if (mQuad == null)
{
mQuad = new FullScreenQuad();
GameObject quadObj = mQuad.GetGameObject();
quadObj.GetComponent <MeshRenderer>().sharedMaterial = mRenderToBRDFMaterial;
quadObj.layer = LayerMask.NameToLayer("RenderToCubemap");
quadObj.transform.position = mCamera.transform.position + mCamera.transform.forward * 5.0f;
}
mCamera.targetTexture = mBRDFMap;
mCamera.Render();
RenderTexture.active = mBRDFMap;
Texture2D brdfLUT = new Texture2D(mBRDFMap.width, mBRDFMap.height, TextureFormat.RGBAFloat, false);
brdfLUT.ReadPixels(new Rect(0, 0, mBRDFMap.width, mBRDFMap.height), 0, 0);
brdfLUT.Apply();
byte[] bytes = brdfLUT.EncodeToPNG();
File.WriteAllBytes(mOutputPath + "brdfLUT.png", bytes);
DestroyImmediate(brdfLUT);
brdfLUT = null;
mCamera.targetTexture = null;
DestroyImmediate(mBRDFMap);
AssetDatabase.Refresh();
TextureImporter textureImporter = AssetImporter.GetAtPath(mOutputPath + "brdfLUT.png") as TextureImporter;
textureImporter.textureType = TextureImporterType.Default;
textureImporter.mipmapEnabled = false;
textureImporter.sRGBTexture = true;
textureImporter.filterMode = FilterMode.Bilinear;
textureImporter.wrapMode = TextureWrapMode.Clamp;
textureImporter.maxTextureSize = Mathf.Max(512, 512);
AssetDatabase.ImportAsset(mOutputPath + "brdfLUT.png", ImportAssetOptions.ForceUpdate | ImportAssetOptions.ForceSynchronousImport);
}