Performance with Solid/Hollow geometry

I’m new to UE4 and in game making in general, and I have a question about the use of geometry. When you create a box for example, you can set it to solid or hollow. Will this make a difference in overall game performance? When I test it in the editor, everything seems to run fine, but I was just curious as to how this factors into the memory. I have some buildings that are just there for show, so it doesn’t seem necessary to make them solid since only the outside is visible. My guess is that it would be negligible, but if I had a big enough game and everything was set to solid would that eventually take its toll on rendering?

Well, I don’t think it’s the preferred choice to use geometry in the game, just convert it to FBX and the normal draw call ‘rules’ apply?

There is no such thing as a ‘solid’ object. All objects are just made out of faces. Some can have faces on the inside but there’s no solid object.

Well, I think there might be conflation of terminology here. The Geometry tool does give the option for Solid, Semi-Solid and Non-Solid; plus it gives additive and subtractive options. Then you got (which I *think *is where the conflation is) the option to make a box/cube and cylinder shape ‘hollow’ in the options.

So, the poster is (again, I think) asking whether if making “…some buildings that are just there for show…” hollow, thereby increasing the total amount of geometry by 6 faces per building, makes any difference to performance.

My answer is that, BSP is not to be used for final game, but if you have something which is just for show, like a row of buildings; then test with BSP, but convert to static mesh/FBX and use optimisation in-engine to figure out what the ‘hit’ is to your frames.