Per Poly Collision


I have tried everything , and still cant understand per-poly collisions.I have exported mesh from 3ds max - simple geosphere - around 800000 polys . When i check option in static mesh editor - Use Complex Collision as Simple - my original poly count for mesh is not used in collision. When i visualize Complex Collision - there is maybe like 400-1000 polys from my original 800.000 polys ?.

Is there some limitation with per poly collisions ? Max number of polys ? Or i am doing something wrong ?

I have following situation . I have high poly mesh terrain : around 8mln polys . How to setup collision for this mesh to use original rendered mesh for collision detection ? If i use "Use complex collision as simple " option , situation above repeats . When i check Use Customized Collision , and use my original visual mesh as complex mesh , situation repeats .

I have lost my mind on this . In unity when i check mesh collision , every single triangle is used in collision mesh , even if it has 8mln polys. I know its slow , but i need to use my visual mesh as collision mesh .

Hope anybody can help.

I made a similar post recently, I’m having the same exact issue. I’m adding a comment so hopefully this gets more traction. Did you ever find a solution?

I ended up finding the issue, my mesh had Nanite enabled and it generates a lower complexity version of the collision mesh. A quick workaround I did is made a duplicate of my mesh with Nanite turned off, and used that mesh as my custom collision mesh.