So I have made the most basic scene I can to illustrate the issue. It seems like a bug. But I also don't know houdini well, so it's hard to tell.

Attached there are 3 scenes.

ballCombinePost if you open and go to renderview and try to render with ipr. the hair doesn't render. And I have no idea why. both mantra and octane have this issues by the way.

here are the steps to reproduce what I have done. open ballCombine, and file merge in HairSphere. delete cam2 then plug the some Animation into the sphere object. great, the sphere is now parented to the null animation. so we need to go to skin and update from sop so the hair grooming is attached. I also set the method to transfer direct. since it's just transform data. Great that works, now the hair is attached to the sphere that is being animated by the null…. Except now the hair doesn't render.

any ideas? I am stumped. looks like a bug to me, as it is very straightforward what I am trying to do. If you don't do any grooming it works. and the hair auto sticks to the ball once it's parented to the null.

Thanks
Chris

it should also be noted that the hair disappears in render when you first plug the null into the sphere object. in the viewport it's floating around not attached to the ball, but nothing in render. and once you disconnect from the someAnimation null the hair starts showing up in the render again.

“If you dive into sphre_object1_fur->guides->groom_on_old_skin, please move the render flag to the curvegroom node. It should render then.”

Tech support got back to me with the answer, if anyone else runs into this. Here's a big thumbs up for great support!