FaceGroup Splitting

Bug Report
1

THE PLATFORM: iPad
NOMAD APP VERSION: 2.8

I’m using nomad to design jewelry. A very common use case for us is to place diamonds on a jewelry piece, where we set “cutters” which we use to boolean a seat for the stone to be set in, and the diamond it self, just for visual preview of how the stones would look on the piece.

Inside the cutter, I would have a diamond model with the matching size, e.g a 1.0mm sized stone inside a 1.0mm sized cutter. We also usually work with different size of stones on the same project.

To make the selection easier, what I would do is assign a different facegroup for the cutter and the stone, so I can later merge them all together, and then split by facegroup. This allows me to have 2 distinct objects for the cutters and the stones.

This works beautifully for a single cutter + stone, however, it when working with multiple sized cutters, they will be split into separate objects per size, even when the hex color code is the exact same between cutter 1.0mm and say cutter 1.2mm.

Is this a bug or a known feature limitation on how the split by facegroup works?

To visualize:

  1. Import 4 models:
  • cutter_1mm
  • diamond_1mm
  • cutter_1_2mm
  • diamond_1_2mm

Assign facegroup color #000000 to cutter_1mm and cutter_1_2mm, assign color #ff0000 to diamond_1mm and diamond_1_2mm.

Now join cutter 1 and stone 1, and the same with cutter 1.2 and diamond 1.2.
Use insert to place cutter+stone at different places.

Join all layers of 1 and 1.2mm Now split by facegroup.

The result is 4 layers:

  1. Contains all cutters of size 1.0mm
  2. Contains all cutters of size 1.2mm
  3. Contains all diamonds of size 1.0mm
  4. Contains all diamonds of size 1.2mm

I was expecting the result to only result with 2 objects:

  1. Cutters 1.0mm AND 1.2mm (since they’re both #000000)
  2. Stones 1.0mm AND 1.2mm (since they’re both #ff0000)

I’m also using ZBrush when I’m at the workshop, and using polypaint and group by polypaint works flawlessly there, splitting the result into 2 subtools only instead of 4 like in nomad. With the same logic I was expecting nomad to do the same.