Chris Klinkhamer


About Me

VFX Artist



Houdini Skills


Not Specified

Recent Forum Posts

USD - Making hairs inherit visibility of root prim (or mesh) Sept. 27, 2023, 7:51 a.m.

We have a character with multiple limbs, sometimes limb_a is visible and limb_b is invisible. Both of them have grooms. Now when using the hair procedurals in 'deform' mode, we can't get it to work.

As soon as we set a AddInherit via python the fur is invisible for the hidden parts en visible for the shown parts, so that works, but this is without deformation.

But when using the 'houdini preview procedurals' node to also deform the fur or even when rendering, the whole system breaks. Without the AddInherit(s) the deformations work. So it seems like the AddInherit also makes the fur rely on some sort of location/transformational things...

How can we get the fur/hairs only look for the actual state of visibility of its linked mesh?

Hair root deformation issue when importing maya usd anim? Aug. 24, 2023, 10:30 a.m.

As shown in the 2 image previews I made a simple setup from the rubbertoy with hairs.

I can layer animations from Houdini and the hairs get perfectly fine deformed/transformed. But when I import the rubbertoy in Maya (doesn't matter if I imported it as an USD or OBJ) and then export it as a .usda file I get really weird offsets on the roots of the hairs, when sublayered to the original asset.

In the attachments you can also see it has the right hierarchy, the USD settings and also a hip file.

What makes it even more interesting is that if I use a sopmodify and unpack the purpose:render geometry to polygons the issue suddenly disappears. But this beats the purpose a bit considering the speed of USD.

The reason I want to import the usd from maya is because of animation purposes ofcours. Also .usd, or .usda doesn't make any difference.

Kind regards,

Groom inherit visibility from skin? Aug. 23, 2023, 10:55 a.m.

We have characters animated, but some of them have multiple wings for example. One for flying, one for standing etc. Now we have grooms on both wings, but when the flying wing is visible we don't want to see the groom of the standing wing. For the geo this already works, but for the groom it's a different story. Is there something I am missing to make the groom inherit the visibility of the geo? Or does this involve a custom setup in SOP Modify?

Kind regards,