Hi. Finally, someone with the same problem. I can't believe this isn't affecting more people. I arrived at the same conclusion too, that the density map is conflicting with the clump modifiers. I was about to open a new post but then found this one. Having completed my groom for my character, as soon as I try to move the scalp mesh, part of the bangs/fringe just extends longer than the rest of the hair - and this is not acceptable. The problem disappears if I disable the clumps or disconnect the density mask. I have been in a lengthy support case arguing my point, and I think they have reported it now to the development team.
When I say 'move the hair' I mean either by parenting it to the character rig, or just by dragging it with the translate tool in the viewport - no dynamics or complicated alembic setups yet. I have also tried wrap deforming the scalp mesh to the character's head geo. I've also tried the "duplicate the scalp mesh and create a blendshape technique" which doesn't work either, and neither does changing from parallel to DG in prefs.
The only work around so far that is moderately acceptable is to increase the tesselation on the scalp mesh, add an edge loop where the density mask border is, and delete faces to shape the scalp mesh to the shape of the density mask. Then you can delete the density mask altogether, and have to start your groom again using the old guides as curves for the new groom. Save a preset from the old groom and apply it to the new groom to save some time. However, this will only be of use if your scalp mesh has a hard edged density mask. If you need parts of the hair to be thinner with shades of grey, eg. balding on top, or perhaps around eyes and nose for a creature with fur, then you're in trouble unless you want to convert all your hair to polys, but that drastically increases file size, at least for the scalp with a lot of hair. For my character's eyebrows I will have to convert to polys because they have density masks and clumping but obviously fewer hairs = fewer polys. So if you want clumping and density masks in your groom, which is pretty much always, then I would have to say XGEN IGS is unusable at the moment (please fix it Autoflow). Have a look at the attached file and video. Thanks.
