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Decimation Master and PolyGroups....

ZBrush Usage Questions
#1

Hi Everyone!
Hya ZBer!!!

Is there a way to use decimation master and keep polygroups?
The only way to break an object up for rendering diferent materials in KeyShot is to have polygroups and I cant make it work right with things I want to rig (or for that matter most of the stuff I want to do).

Heres what I want to do:


  • Make high res model in ZBrush (with Polygroups).
  • Decimate it in ZBrush and export it to Blender for rigging and posing.
  • Bring it back into ZBrush to apply materials.
  • Export to KeyShot for rendering using materials I make in KeyShot.

Am I doing this wrong, or is it possible to even do what I want to do?

I can rig the decimated version of the thing I made, but I loose all the polygroups and so I cant render it in KeyShot unless I want it one static material, and that defeats the whole point of even having keyshot in the first place.
I can polypaint it, but that is still one static material, and frankly looks stupid, like I colored it in with crayons or something.
As they say on the internet:
“Meh”

Anyhow, any help would be nice! Seriously nice, I have been dead ended with keyShot because of this problem since I got it.

Cheers!
Mealea

#2

Why not use ZRemesher instead as it keeps polygroups?

If you really prefer Decimation Master, try this:

  1. Split the group by going to “Tool > Subtool > Split> Groups Split”.

  2. Use "Decimate all Subtools

  3. Now go to “Tool > Subtool > Merge” with “Weld” On to play safe.

#3

I just remembered that you could also polypaint the groups before Decimating, then after Decimating you could “Groups by Polypaint”.

#4

Dillster,
Thank you, I tried those things.
ZRemesher destroys too much detail, actually it destroys all of it.
Splitting groups does not work because there are too many of them.
The idea of using PolyPaint ALMOST worked, but it makes some seriously messed up edges and they dont work at all in KeyShot.

Decimation master brings down the polycount like crazy, keeps all the detail, but sadly deletes polygroups.
Blender, which is what I’m using for rigging, cant cope with bending the stuff I’m trying to bend, the polycounts are too high. Decimation Master seems to be the way to go, but losing all the polygroups makes rendering diferent materials in diferent areas in KeyShot impossible.
Im curious now if there is a way to project polygroups from the original mesh to the decimated mesh, they (the two meshes) are the same size and shape, maybe that would be doable… somehow.
HMMMMMMMMMM…

Thanks for your ideas, and you surprised me, I dont think many people know the polygroup to polypaint feature!

Cheers!
Mealea

#5

@MealeaYing hey! Couple years later im looking for a solution for the exact same problem: decimate and keep polygroups.

Did you end up finding a workaround for this?

#6

Modify Topology->Unweld Group borders, then Freeze Border when decimating is the official recommendation. Unfortunately, it locks up for me when reordering for dense meshes ~10mil polys