Engine plane:
- remove any and all simple collision from it, no more hull
- use complex collision as simple, we’ll use every triangle instead which is 2 tri only, yay!
- enable dual sided geometry, still 2 tri
Now you have a 2 triangle plane with double sided collision. Whether it’s faster than a box is arguable, but I wouldn’t argue as I have no clue. There might be optimisations here I’m not aware of. When you take it closer to the metal, though, colliding against a single poly is faster than against 6.
I feel the engine obfuscates things a bit. In UE physics sims (for example) does not allow for per triangle collision out of the box. You’d need to import your own collision and then use Complex as Simple - it works well enough. I guess the limitation is here to prevent people from having overly complex simulating meshes.
You can, of course, collide against complex geo with ease.
So yeah, I kind of want to say that double sided geometry trace with complex collision instead of box hull will be faster. Anyone wants to set up a test?