Groom physics simulation issue

Hi everyone, I’m trying to get a groom to work for one of my characters and it seems to work well outside of the physics simulation. The first and major problem I have encountered is that enabling physics simulation eliminates my hair clumping (using the clumping feature in Blender to have all interpolated children of a hair strand converge at the tip). The physics simulation treats the hair as if the clumping doesn’t exist. Is there a way to prevent this from occurring?

Physics simulated hair on left, un-simulated on the right (matches what I see in Blender)

My second issue involves the hair at the nape of the neck. I added a simple wind only in the Y direction (left to right), that varied with time a bit. The hair moves as expected in all places except this area, where it seems to move up in the Z direction and I can’t figure out why. I found that turning off the Solve and Project collision settings in the groom asset (physics tab → collision constraint) stops the hair from misbehaving but causes a lot of other problems with the rest of the hair in doing so. A simple work around would be to separate the short hair from the long hair and have them as two different groom assets, but I was wondering if anyone had an idea what the issue is here.


Not sure if the video is working properly above, so a direct link to it on imgur can be found below.

Any help that you can provide would be greatly appreciated, especially on the clumping issue since the short hair doesn’t really need physics simulation.

Edit: Seems like the nape of the neck was caused by a physics body problem, just increase the size of the head physics body to include the lower neck area (you might also need to reduce the torso’s influence in that area but I’m not 100% sure). The de-clumping problem seems to be a Strands Density issue predominantly, but a lot of other settings influence it as well.