To create face groups

Colorize triangles and let Netfabb derive the new face group

Use the Texture and color editor to set colors to triangles. Triangles with the same color will, after conversion, belong to the same face group.

1. Select the part.
2. From the main menu, choose Modify > Texture and color.
3. In the context view, choose a color different from the part's current one(s).
4. Use the brush tools ( Color triangles, Color with brush, or Color shells) to apply the color to those triangles that should end up belonging to the same face group.
   Tip: Repeat steps 3 and 4 as necessary.
5. In the context view, switch to the Face groups tab and click Conversions > Color to face group.

This uses the colors to set or add information to each of the triangles about what face group it belongs to. To clear all face groups (equivalent to setting all triangles to belong to the same group), perform the same steps, but coloring the entire part in one single color.