Xgen IGS imported descriptions re-seed clump maps

[Anonymous]

I need to export a description to from one mesh to another. The mesh shapes are identical but the vert order is different. When the groom is imported onto the new geometry the clumping changes, as if the "point randomness" value or a seed value somewhere on the clump modifier changed. This wrecks the groom. Is this a bug and is there a workaround? 

To recreate: create a new groom on a sphere. Add a clump modifier. Export the description. Duplicate the sphere and insert a few spans. Import the description onto the duplicated sphere. Compare grooms. The clumps on duplicated geometry should have shifted dramatically where the new spans were added.

thanks

[mspeer]

Hi!

Try Transfer Vertex Order.

[Anonymous]

Thanks for the reply. This is part of a bigger issue where the growth scalp causes hairs to glitch to origin for a single frame. Completely rebuilding with verts in the same position still causes the problem, but smoothing the mesh fixes it. Unfortunately the randomized clumping on groom transfer ruins the groom.

[sean.heasley]

Hi @Anonymous

Does smoothing the mesh fix this or does the groom still get ruined by the randomized clumping?

[sean.heasley]

Hi @Anonymous

Just wanted to check in to see how things were going. Are you still having this issue?

If your issue is resolved, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Anonymous]

Hi Sean, thanks again for following up. No luck I had to re-do the groom. Looks like any point order change causes the clumps to re-seed. This is part of a bigger problem where during animation hairs would glitch to origin randomly on single frames. Had something to do with the growth surface but I couldn't figure out what. Even rebuilding the mesh from scratch and transferring vert order/uvs would cause the problem. Importing the grooms onto a denser surface seemed to solve the problem, but caused the re-seeding issue.

[sean.heasley]

Hi @Anonymous

I know you had to re-do the groom, but is it possible you could create a video of this issue so I can see exactly what's going on?

If you need a video capturing program, Screencast is a great option that we use here at Autodesk

[Anonymous]

Hey Sean,

The re-seeding is very easy to re-create:

Create a sphere, duplicate and smooth.
Create interactive groom splines on the original sphere. Add a clump modifier.
Export the groom description. Import the groom description onto the smoothed sphere.
Compare and the smoothed version will have different clumping.

Guessing the clump modifier relies on vert order? Is there an eta on guide clumping? That would solve this.

Unfortunately I can't send a video of the glitching hair. It's studio work. I know that doesn't make your job any easier.

thanks

[sean.heasley]

Hi @Anonymous

I think this may be a known issue. I'm doing some further testing and checking with our dev team and I'll get back to you!

[sean.heasley]

Hi @Anonymous

I went ahead and logged this with our dev team so they can work on a potential fix!

[Anonymous]

Thanks Sean, you're always on top of this stuff! Is there an ETA on a proper release of clump to guides?

[sean.heasley · Accepted solution]

Hi @Anonymous

At the moment I can't say when we have our next updates planned but this type of change should be in the release notes with the patch that resolves it!