How do I make compounds in the level editor?

[Statyk]

When you have selected for example 1 room with B,
Then when you have placed the compound, RE-PRESS B and move your { Un-compounded} room a little bit farward and backwards.. -> you will see the walls change a little bit of their position. <- THAT is how it must be!
If you do not do that, there is a possiblility tat you next walls\ etc, won't be placed how you want.

This is because your compound contains translations of objects on the X, Y, Z that are not grid snapped. Let's say you compound two walls.

Grid Snap: On - 0.25
Wall A: 0 0 2
Wall B: 0 0 6
+ When compounded, they will remain in their proper positions when moved about the grid. No gaps between the two after moving them.

Grid Snap: On - 0.25
Wall A: 0 0 2
Wall B: 0 0 6.1
+ When compounded, Wall B will round down the Z axis and will snap back onto the grid, lining up the walls like above. No gaps between the two after moving them, even though there was one before moving them.

Grid Snap: Off
Wall A: 0 0 2
Wall B: 0 0 6.1
+ When compounded, Wall B and A will retain the most accurate number along the Z axis as possible, leaving the gap you had between the two. Fallback = no proper grid snap without lowering the grid snap to 0.1.
So when moved along the Z axis 4 units:
Wall A: 0 0 6
Wall B: 0 0 10.1

Understand? It's not "a bit weird sometimes", you just don't understand why you're doing something wrong =P

So basically, if you create a compound containing an object NOT following the grid snap, don't have gridsnap on when moving it, or don't add it to the compound.