Posed Model has Artifacts on Higher Subdivision Levels


#1

Mudbox 2016, model sculpted and retopoligized several times using auto retopology in Mudbox. 4 subdivision levels.
UVs also done in Maya. Not great, but found zero change after substantial editing of UVs.
I’ve taken the lowest Subdivision level, rigged it in Maya and imported the
posed geo as .obj - the artifacts are there no matter what I’ve tried.

I tried using the 2cond and 3rd subdivision levels.

I tried improving the UVs.

I used FBX export to export geo of the pose and imported that as a layer. Same.

I imported the FBX geo with a simple rig and posed it in Mudbox 2016 and exported that geo and used it as a layer. Same issue.

I unchecked “Delta to Base Layer”. I tried matching geo with Vertex ID
and UV - both imported the pose just fine but the ‘skin disease’ that
afflicts the model is the same.

I also tried reducing the pose by 50percent and that had some effect.

A strange kind of workaround was to reroot the skeleton to the head and
build the entire pose from the head down. This worked but it’s
ridiculous and impractical.

Because I tested every variable I could think of in both Maya and Mudbox and neither made a difference I
can’t tell if the issue is in the geometry or in the software - is the
geometry just too far from the base model in Mudbox to make an artifact
free model on the highest subdivision level?

Why was the issue the same when using the pose tools in Mudbox? Or was is the problem a
Maya problem which gets imported with the rig in the FBX format?

And why is the issue a consistent acne-like artifact which appears over the whole surface?

I’m currently teaching a class of students digital sculpting and I thought
the workflow would be pretty dependable. I’ve used it before without
this particular issue.

Any thoughts, ideas, insights appreciated.


#2

have you tried that in mudbox 2018 there are several bug fixes in that direction in 2018.1


#3

I haven’t tried it in Maya 2018. We are an educational institution and I have an educational version of Mudbox 2016 which we aren’t in a position to update right now.

I’m looking for a solution that works with Mudbox 2016.

Thanks for the tip though.


#4

could you upload a scene with this issue.?


#5

Yes, absolutely!

https://www.dropbox.com/s/q27bwsd7l0i5gze/Tanya_Jaiswal%20superhero_v13.mud?dl=0

Any insight would be appreciated!


#6

Hello!

were you able to download the file? Any ideas as to why it has developed a horrible case of acne?

Cheers,

Ethan


#7

I found a solution to the acne/bubbles on the skin:

The following link, STEP 10, describes a solution:
https://www.3dartistonline.com/news/2015/07/how-do-i-pose-a-sculpt-in-maya/

In a nutshell:

  • Export Displacement Map
  • Delete all subdivision levels
  • Subdivide mesh to original level
  • Use ‘Sculpt Using Map’ to recreate your sculpture

This should get rid of whatever corruption was causing the bubbles. I had to try several settings before I got a workable displacement. The settings I used in the end were Raycasting > ‘Closest to lowres Mesh’ > 4K image > 32 - bit exr

Hope that helps anyone in the future.

Btw. I updated to 2018 and the issue was still there.