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I am wondering if there is a way to cast shadow from a height map rather than using a displacement map using Cycles X.
I believe it was mentioned that such high-speed and low-memory tricks (like parallax occlusion mapping) are better suited for Eevee than Cycles. The reason is that Cycles is geared towards being as high quality as possible while Eevee is the engine designed for insane speed.
The Eevee Next project is underway, this might be a good thing to show Clement.
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I feel this should be added to cycles as well. Eevee is great but Cycles gives more accurate results especially with reflections and caustics so I think it would benefit both renderers. Let the artists make their choice if they want to use it for Cycles or not. This will save the need to create very tiny displacements to catch shadows that eat a lot of memory and take longer to render.
I think there is already some sort of pixel depth offset which is used to blend materials between meshes when placing meshes on a landscape.
AFAIK, Pixel Depth Offset (PDO’s) is not really a suitable technique to be used with true raytracers like cycles (and it’s not compatible with raytraced shadows, according to nVidia RTX developer faq (located here). It’s a technique relevant to GPU physically based rendering, where shadows can’t be raytraced. And in case of RTX capable hardware, raytraced shadows and PDO’s are mutually exclusive, one or another, since PDO’s produces artifacts on that case, and needs to be baked or configured to be zero when using raytraced shadows.
And remember, classic brute force physically based raytracers are not the same as physically based GPU renderers. Both are quite different beasts, and should be treated as such. Maybe in the future when GPU’s tech evolve more, this can be a thing of the past, but for now, enjoy Cycles, EEVEE and Unreal for what they are.
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Really appreciate the info you shared. Thanks. 