Level's BSP Model geometry is broken

  • Build Type: Fresh Binary from the Unreal Launcher
  • Build Version: 4.16.2
  • Description: Just start a new empty level, turn show flag “mesh edges” on, and start playing with BSP brushs. Add a couple of brushes, move them around, and eventually you will see the model geometry goes haywire (you might have to overlap some brushes to trigger). Creating a static mesh from one brush seems will result in an updating and fixing of all other brushes (sometimes), but it does yield a proper static mesh (most of the time). I would like this to be fixed because I am trying to define my own C++ brush builders (ie the TorusBuilder brush below).

Hey instantmelanie,

Could you be more specific in your description of what you mean by ‘haywire’?

The only thing that seems a bit odd is the flickering that occurs which is caused by Temporal AA and not easily fixable. A bug has been entered for this flickering behavior (UE-30764)

Thank you,

Yes, look more closely at the first image. There are edges on the brush that shouldn’t be there. The second image shows how the extra edges disappear once I convert the brush to a static mesh. My custom torus brush better illustrates the issue but I just want to know why the engines default brush has these extra edges, or at least appears to.