How can you see which meshes (occluded or not) are currently drawing?

When optimizing a map, one thing we always have to do is make sure that every mesh that’s drawing really should be drawing. Usually there are a number of reasons why a mesh might be drawing when it shouldn’t, such as there’s a tiny hole in a wall that you’d never have noticed. In idtech we’d turn on a cvar called “r_showtris 2” which draws a wireframe overlay on top of all the polys that are currently being rendered, whether they’re occluded or not (but vising is still on so if a mesh is told not to render because it’s occluded, it’s polys won’t draw). So you can walk around and see through your walls and see what’s drawing and then try to figure out how to address whatever problems there might be. I can’t seem to find an equivalent to this in unreal…? The closest I could find is r.visualizeoccludedprimives, but that’s NOT what i’m looking for. It doesn’t show you what’s drawing, it shows you what isn’t drawing. So you will have tons of cases where you see about 99 bounding boxes and because you see so much stuff that isn’t drawing, you assume there aren’t any problems… But what it doesn’t tell is that there (n) meshes drawing that shouldn’t be. So it’s basically useless.

There’s also the freezeworld command, but that’s also pretty useless because when there are T-junctions or tiny holes in the walls, those are very hard to find. if you look at the wall and strafe along it, it will very often only draw the mesh that shouldn’t be drawn for about 1 or 2 frames because that hole is very very small. So if you analyze how many frames were passed as you walked along that wall, it will be a ton. You’re rendering at 120 fps and walked for 3 seconds, so that was 360 frames that were rendered and the hole was only visible for 1 frame, so you have 1 in 360 odds, which means that you’d have to use freezeworld 360 times in order to spot that hole and as you can guess, that’s completely impossible. You’d have to start walking, freezeworld, fly away and inspect what was drawing, then go back to EXACTLY where you were last time you pressed freezeworld again and then move 1 pixel to the right, and repeat. Obviously that’s impossible.

There’s also SHOW MESH EDGES in the editor, but that doesn’t draw the wireframe on the occluded polys and plus i assume hardware occlusion doesn’t occur in the editor anyways. (I’ve been editing my level in vr and I’ve found that the framerate was unacceptable, despite there being a poly right in front of me that’s covering the entire screen so that proved it was drawing the entire level even though it was all 100% occluded. I then had to hide half the level to get the framerate back up to a usable amount. So that proves that occlusion either doesn’t work in the editor or it doesn’t work in the editor while you’re in vr…)

There’s also wireframe mode in the game you get with F2 i think, but that doesn’t work because it turns off hardware occlusion.

So those are the four things i know of and none of those come close to what I actually need so is there a cvar to draw a see through wireframe on top all the rendering polys that none of us know about? There’s got to be a way to see the meshes that are drawing behind the wall you’re looking at because how else can one find the vising problems they have to fix?