Hello, I have a rigged character in H 18 and my Groom is not following the characters animation. This only occurs once I have placed a guidegroom modifier in the Groom node. If I bypass the guidegroom the animation works and the hair deforms properly.

How can I fix this?

Hi,

you're not giving enough information. The initial groom usually only creates a single “state” (rest state), while a “deform node” is taking your animation (point positions) and applies offsets to the initial groom. So a standard setup for groom data is a two-node set: Groom + deform.
If you aren't doing anything to the groom-data (basically curves or groups of points), you are basically “moving everything”.

If you can create a simplified test HIP file of your scenario it might be easier to help.


Marc

Thank you Marc! I have attached the rig with a deforming cylinder.

Hi, Brad,

the groom needs to happen on the REST pose, i.e. the input to the groom node needs to come from the original tube geometry, while the input to the deform node (“animated skin”) needs to be the deformed one.



Note that “input skin SOP” on the groom node points to your undeformed original geometry.

Marc

P.S. Hint: You can speed up hair usage in Houdini dramatically if you cache out the groom result to a file (it's a single frame only), that will avoid cooking the groom node on every single frame. Sample applies to deform, obviously, but that's one cache file per frame, so much more disk usage.

Thank you Marc- that did it!