I’m fairly new to Rendering in Unreal Engine & UE5 and so I’m struggling to understand a few things and wondering if anyone would be able to help me.
I’m currently running a number of full-screen passes in C++ and instead of rendering to the screen, I would like to be able to expose the resulting texture from these various passes into something that I can use inside of the Material Editor. Similar to how we can access the SceneTextures (SceneColor, DepthColor etc…)
Here is an example of one of the many passes I’m doing using the GraphBuilder and a custom shader:
FScreenPassRenderTarget ColorTexture;
ColorTexture.Texture = GraphBuilder.CreateTexture(SceneColor.Texture->Desc, TEXT("Scene Color Copy"), ERDGTextureFlags::None);
//Brightness Texture
if (BrightnessPass) {
// Shader setup
TShaderMapRef<FTestShaderPS> TestPixelShader(GlobalShaderMap);
FTestShaderPS::FParameters* TestShaderParameters = GraphBuilder.AllocParameters<FTestShaderPS::FParameters>();
TestShaderParameters->ViewParams = SceneTextureViewportParams;
TestShaderParameters->SceneColor = (*Inputs.SceneTextures)->SceneColorTexture;
TestShaderParameters->SceneColorSampler = TStaticSamplerState<SF_Point, AM_Clamp, AM_Clamp, AM_Clamp>::GetRHI();
//Render to the screen if we are in preview mode
if (PreviewPasses) {
TestShaderParameters->RenderTargets[0] = FRenderTargetBinding(SceneColor.Texture, ERenderTargetLoadAction::ELoad);
}
else {
TestShaderParameters->RenderTargets[0] = ColorTexture.GetRenderTargetBinding();
}
TestShaderParameters->Threshold = Threshold;
TestShaderParameters->Intensity = Intensity;
FPixelShaderUtils::AddFullscreenPass(
GraphBuilder,
GlobalShaderMap,
FRDGEventName(TEXT("Render Brightness")),
TestPixelShader,
TestShaderParameters,
Viewport);
}
My idea was to expose my ColorTexture property to a Material Expression so that it can be referenced in the Material Editor but it seems as though the Compiler can only take a UTexture/UObject as an input. I can’t seem to find a way to convert the FRDGTexture/Resource into a UTexture. that the material compiler can use.
Does anyone know of a way to achieve what I’m trying to accomplish? Or, perhaps of a better way to expose my resulting texture somehow?
I tried rendering the result directly to a Render Target and just using a standard Texture Input node, but it had a number of issues – so I figured that perhaps exposing this FRDGTexture to the compiler directly would be better.
Worst case scenario, I can do all of my post-processing using the above techniques – but I was really hoping to rely on that as a last resort and only use C++ for things the Material graph can’t do very easily.
Much of this stuff seems quite difficult to find any information on. So any help would be greatly appreciated, thanks!