Set the interpolation to closest.
Found interesting ways to fix it.
In the simple reproduction file, set kink amplitude to 0.02 (down from 0.2). Or, set diameter scale to 0.001 (down from 0.01). The scene now builds within a…
Got a simple reproduction.
For the 4.1 splash screen. Setting interpolated hairs to 14 (down from 15) makes the build quick again. Or you can keep it at 15 and set the kink type to nothing,…
Can reproduce on Windows 10 and Ubuntu 23.10 with CPU BVH2 (I don't have enough VRAM for that scene). The main problems are the two carpets. The carpet in the camera view (Furniture → Small →…
I add a new here Blend file with unique scenes to produce each image in Case 4.
The straight curve seems to only have the issue on CPU and only when the ray that hits the outside also hits the…
I didn't think about testing other BSDFs, but yes, it happens even with a diffuse BSDF.
The two biggest changes you need to make are making the hair's radius 40um and setting glossy bounces to something like 16. You should also change Factor Min in Set Hair Curve Profile to 1 (only…
Commentary on the last real reference you posted. While the average pixel level is low, this is likely due to a low exposure either in camera or post-process. There are decent highlights and…
I don't think Huang has an energy problem. The specific setup that you shared happens to highlight a difference between the hair models. (all of the following images use 0.1melanin, ior 1.5, and…
Can not reproduce with an external touchpad on two different PCs in Windows 10 or Linux.
The Principled BSDF went through a lot of changes. You can see this by changing the walls and floor to diffuse, the lighting in the room is the same on 3.6.5 ![4m8s 365.png](/attachments/cf537454…
Still happens with the new updates. 2,000,000 samples.
![2000000.png](/attachments/6a7383b…
Made a simpler scene that renders faster. It also highlights the other fundamental issue: hair density. In this scene, setting hair density to 5000 does not produce the issue. ![20000sample…