Subtractive Meshes

I want to make a gap in my second floor for stairs to go through, so I made a Subtractive Mesh.

I used this to make my bathtub grouped it and then was able to put a mesh in for the water, but it does not seem to work for my floor. Any Ideas?


You should use BSP only for blocking out your level. For higher detail always use static meshes.

If i had to deal with your problem, i would export the BSP with the hole as a static mesh and reimport it,
so there are no more subtractive bsp brushes.

That would work, except then I had this issue

Looks like a sorting problem. Create your ceiling first, subtract your box and create your stairs afterwards.

Download Blender, learn blender, make proper meshes, no excuses here.

There was dropdown menu when you right click CSG brush, it allows “bring to front” or back, and up down in order for brushes. But that was in UT3, and i think this must be somewhere in unreal 4.

Just to note, you can create a basic static mesh in UE4 by converting your BSP into a SM.
Its not entirely ethical, but it works.

Personally, I use BSPs for my environments and either replace them or leave them. Static Meshes are for from and other small things (i.e. and archway).
I think it really comes down to you, don’t feel like you can’t use BSP brushes for your environment because its “unethical.”
If you like it, use it. It comes down to whether or not what you create is worthwhile.

Just figured I’d throw that in there.

Good Luck,
~ Jason