GIprobe artifacts when adding brush to a group

[fossegutten]

Edit: Using Qodot 1.6.2

Steps to reproduce:

1. Create a brush in trenchbroom.
2. Create another brush. Add it to a group with random name. ( only this one will not be baked properly)
3. Create another brush. Create a brush entity. Then add it to a group with random name afterwards. (Adding to a group if it is a brush entity works fine).
4. Import map with Qodot.
5. Create a GI probe, and bake it.

Artifact to the left. Normal to the right.

[Shfty]

This is due to the func_groups TrenchBroom piggybacks on for its internal grouping functionality aren't recognized by the 1.6.x FGD, and thus come through as non-static entities.

This behavior is more controllable in the latest commits to master, but for now the solutions are: A. Make any brushes inside TB groups entities, and set _shadow if their classnames aren't set to merge with worldspawn B. Add a func_group FGD entry and set it to merge worldspawn. This will break the nested group functionality for now (fixed in master) C. Avoid using TrenchBroom groups for static geometry