Loading a GLTF with a refractive material which additionally has some roughness looks like this: [image] The result is not very pretty — I’m wondering if it’s possible to increase the quality of the mipmaps on the opaqueSceneTexture which is used for displaying the refraction? I have tried to in…

Hello! Would you be able to share your model so we can take a look? In the meantime, I’ll tag @PatrickRyan who might have encountered this before.

I can’t share this specific model, but I quickly created a test in Blender: [image] Download with .glb, .gltf and .blend files: RefractionTest.zip (115.2 KB)

Also @sebavan do you think we could add the bicubic sampling? :thinking:

The main issue is prefiltering the render target in real time would cost a lot, so we would need a similar technique to our realtime filtering technique which unfortunately requires a cube texture (expensive to render) to work accurately. I guess we could try an hybrid approach filtering in a bicub…

Yeah I was thinking about the one lod above approach too it might already be enough

I do not think so as roughness 1 will still be blocky :slight_smile: we need a smooth filter to workaround it

@sebavan , since we outside the realm of physically accurate, rather than using refraction and needing to do real-time sampling, could we just use a render target texture at a low resolution - so we aren’t dealing with mips - and then apply a bicubic sample on that texture? I know we are doing most o…

not really as the roughness is not necessarily constant :slight_smile: so the best we can do is kind of blur

Is there no solution to this problem in the new version?

nope, cc @Evgeni_Popov who might have improved some of the samples a bit/

Blurry refraction quality

Questions

Evgeni_Popov May 26, 2024, 5:05pm 12

Here’s a material plugin that uses bicubic sampling to improve refraction:

Bilinear	Bicubic

image698×739 39.2 KB	image710×730 42.1 KB

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Blurry refraction quality

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