What does this button do?

[Radical Batz]

The last button of the level editor that says "Combination" I never wondered what that does, anybody knows here?
Is it useful, is it helpful, what does it do and what is it used for?

[Daemian]

https://wiki.frictionalgames.com/hpl2/to...e_editmode

---

It seems to create groups of static stuff, I never found it useful since it doesn't select the actual objects it just color them.

You don't need the add/remove options, just select toggle and click objects to add/remove from the current group. Simple as that.

[MrBehemoth]

The engine seems to lump static objects together into groups when you load a map. You can see them with inspection mode.

I believe those groups are PVSs (Potentially Visible Set) used to calculate occlusion culling. If that's the case, this button in the editor would be for making your own occlusion groups.

How would that be useful? Well you could use it to boost performance by restricting limiting groups by line of sight, but the engine seems to do a decent job of this all by itself.

Disclaimer: This is completely guesswork and I've not tested it in the slightest.