Camera Capture in Full Detail

Hello.

I am having a bit of an issue with camera capture actors and render targets. I connected a camera to a render target, both in HDR, and in C++ accessed this render target texture and used “ReadPixels” method to get the resulting capture. Unfortunately in HDR the result does not return what I can see in the actual texture, even setting the read flags with SetLinearToGamma(true) / false produces no change to this. In LDR the result has a lot of pixelization and cannot be used for what I want.

What I need to do is capture fractions of a large mesh with a material that reproduces a texture 1:1 without AA nor lighting affecting it, but using emissive colour in unlit surface mode doesn’t seem to produce the exact result that I would like. I was able to do this in OpenGL exactly as I would like, but so far not in UE…

Can you explain to me the following:
.How to sample a pixel of a render target texture efficiently, as it seems that ReadPixels isn’t returning correctly.
.How to make sure that a mesh reproduces the texture correctly without any added effects (lighting, AA, nothing at all, just 1:1 sample)

The purpose is to check exactly which color of the pixel of the texture I am clicking, the texture/mesh and the viewport have absolutely no direct relationship with eachother, and the texture is loaded at runtime correctly (checked with the editor at runtime)

Thank you very much, I hope this community can help me with this issue, any solution both in C++ or blueprint is appreciated. I followed Rama’s tutorial for the heightmap but unfortunately like I said the result is not a correct reproduction of the texture. Solutions in any engine version is appreciated although I was using 4.5. I can post code if necessary

Hey Niktsuki -

Using a Scene Capture Actor and Render Target in the way you describe you are actually coming across the current firewall of our deferred rendering pipeline. I would suggest looking into these presentation to see where you will need to sample the Gbuffer to achieve your desired effect:

https://de45xmedrsdbp.cloudfront.net/Resources/files/TemporalAA_small-71938806.pptx

Thank You

Eric Ketchum