Hi,

I’m running into a frustrating issue. I spent about three hours grooming my hair guides. After adding a Hair Generate node, I went back to modify one of the guides, and now I’m getting this error:

Invalid skinprim attribute values found on guide curves.
You can create correct values using a Guide Skin Attrib Lookup SOP.


While the error suggests a solution, I’m not sure where or how to apply it in my setup. I am still a beginner.

Currently, my network is structured like this: Source Geometry → Guide Groom → Hair Generate at the object level. For some reason, Hair Generate keeps causing issues, even if I replace it with a new node.

Could someone please advise me on how to fix this without losing my existing grooming work? Or is generally a bad practice to modify the guides after the hairgen node has been added? I hope this is not the case afterall it is suppose to be procedural.

I really appreciate any guidance.

here are some images:

Thank you in advance.

Regards,
Chris

It's hard to know what's going on there w/o a hip file.

Hi Citizen,

Apologies for my late reply. Somehow I didn’t receive a notification for your response, even though I’m subscribed to this post. Sorry about that.

I think we can close this now, as it appears to be an error on Houdini’s side. Going forward, I’ll save incrementally to avoid this type of issue, as unfortunately that’s the only workaround. My mentor also mentioned he experienced the same problem and had to reopen the project.

My mistake was not saving a copy—or multiple copies—which I’ve learned to do from now on. Thank you again for your help.

Best regards,
Chris

Hi Chris,

If there is a bug, please report it to SideFX support along with a hip file. In general, if you get the error about missing skinprim attributes, then you go into your Guide Groom OBJ node and place a Guide Skin Attribute Lookup node before the GUIDES output. Make sure the guides are connected to the first input, and the skin to the second, like in the photo attached. The parameters can be left at default.

Hi Liesbeth,

Thanks for pointing that out. I’ll report the bug with the hip file once I’m back home next week. I also appreciate you sharing the screenshot of the connections. It’s really helpful. I’ll keep you updated once I return.


BR,
Chris