MNEE does not fall back to alternative caustic technique when MNEE does not work. #96991

New Issue

Alaska · 2022-04-03T01:27:15+02:00

Alaska commented

2022-04-03 01:27:15 +02:00

System Information
Operating system: Linux-5.16.0-5-amd64-x86_64-with-glibc2.33 64 Bits
Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.54

Blender Version
Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-04-02 21:17, hash: 4537eb0c3b
Worked: Never as this feature was introduced recently.

Short description of error
There are some situations in which the rendering of MNEE caustics are skipped. During these situations, Cycles does not fall back to an alternative caustic technique resulting in a lack of caustics entirely.

Exact steps for others to reproduce the error

Change the render engine to Cycles.
Set up a caustic caster, caustic receiver, and shadow caustic light.
Set the material of the caustic caster up such that it's incompatible with MNEE caustics, but should still have caustics (This can be done by using the Multiscatter GGX microfacet distribution with a glass shader with a roughness set higher than 0)
Notice how the caustic caster is not casting caustics. This is because the MNEE caustics does not support this material, and Cycles does not fall back to an alternative caustic solution.
If you disable the Caustic Caster option on the object, you will see caustics return (using Cycles standard method)

Here is a file with steps 1-3 already complete:
#96991 - Missing Caustic fallback.blend

**System Information** Operating system: Linux-5.16.0-5-amd64-x86_64-with-glibc2.33 64 Bits Graphics card: NVIDIA GeForce RTX 3060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.54 **Blender Version** Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-04-02 21:17, hash: `4537eb0c3b` Worked: Never as this feature was introduced recently. **Short description of error** There are some situations in which the rendering of MNEE caustics are skipped. During these situations, Cycles does not fall back to an alternative caustic technique resulting in a lack of caustics entirely. **Exact steps for others to reproduce the error** 1. Change the render engine to Cycles. 2. Set up a caustic caster, caustic receiver, and shadow caustic light. 3. Set the material of the caustic caster up such that it's incompatible with MNEE caustics, but should still have caustics (This can be done by using the `Multiscatter GGX` microfacet distribution with a glass shader with a roughness set higher than 0) 4. Notice how the caustic caster is not casting caustics. This is because the MNEE caustics does not support this material, and Cycles does not fall back to an alternative caustic solution. 5. If you disable the `Caustic Caster` option on the object, you will see caustics return (using Cycles standard method) Here is a file with steps 1-3 already complete: [#96991 - Missing Caustic fallback.blend](https://archive.blender.org/developer/F12965129/T96991_-_Missing_Caustic_fallback.blend)

Alaska commented

2022-04-03 01:27:15 +02:00

Added subscriber: @Alaska