Problem using Hollow with BSP objects

Hello,

When using ‘Hollow’ on an edited BSP, It reverts back to the original shape. For example, If i use a BSP box and then edit/extrude the faces of the box and then when i check “Hollow” it goes back to the original shape.

Before:

After:

I’m sure I’m missing something but i cant figure it out. Any help would be greatly appreciated.
Thanks!

Bumping this thread to help find a solution.

Hello. It’s been almost a year, but no question should go unanswered. I have the same problem and don’t know what to do about it other than to “Hollow” the BSP before editing. That still has problems on the inside (extruded sections not having interior faces, gaps between extruded and original section) but at least it’s hollow with roughly the right shape. Sorry this isn’t more helpful.

You dont select the hollow, you basicly create another pen geometry inside of what you have created.
The second one’s “Extrude Depth” must be smaller than the first one.

After you pressing enter, Change inner geometry brush type additive to subtractive and then this is how you create rooms, Hollow only works in box shapes, for box-shaped rooms.

Here in the first image you see 2 boxes i have created with pen tool.
The blue one extrude depth is 256
The red one extrude depth is 128

because red must be smaller than the blue since it will hollow inside and fit in it.

in the second image you see how it looks inside of the room perspective.