Imported collision is innacurate

[Kligan]

It bothers me to no end that whenever I import a simple convex primitive as a collision for mesh in ue4, it always manages to mess it up!

I even went as far as experiment to see if it’ll be better if I manually check and triangulate every single face to make sure everything is convex. Doesn’t matter.

Here’s an example, from a collision I imported just now. A 12-sided convex cylinder with 1 loop in the middle:

Import in ue4, a-a-and its all screwed up with extra edges for no reason:

Let’s try a different variant. Two simple 12-sided cylinders with a gap between them:

Let’s see it in ue4. Its screwed up again, but even worse:

That happens to every simple convex collision mesh I import.

Is there a way to fix this mess? Maybe I’ve been doing something wrong this whole time?

[ClockworkOcean]

The problem is, Blender uses quad, UE uses tris. That’s the root of the problem…

[Kligan]

I’m using Maya. And I tried to triangulate. It changes some things but ue4 still manages to screw it up in different places.

[Kligan]

Here’s imported triangulated collision mesh:

Still messed up, but in different places.

[ClockworkOcean]

Yeah, it’s an automated process, unfortunately. This will work fine, and nobody every sees it… :-\

[Kligan]

I know, but additional edges on collision makes performance worse, does it not?

Even if its just a tiny amount; take into consideration that it f*cks it up for every single mesh, some more than others, and it potentially could add up for the entire scene.

At least that’s what worries me.

[ClockworkOcean]

Basically, no. Not unless you’ve got a lot of very hight poly meshes, which are 20k+ polys with ‘use complex as simple’ set.

[Tuerer]

I recreated it in Blender and it’s exactly what I expected it to be:

Maybe your UCX shape has double vertices or something?

[Kligan]

The vertex count is fine. I didn’t even do anything extraordinary with the collision mesh. I just created a cylinder, set sides to 12, added a loop in the middle, and tweaked the XY scale of each loop to match the geometry of the pot.
It must be something else…

[Kligan]

Ok, I figured out what was the issue.

I had this option turned off in the import settings. And without it, UE4 does some random garbage when collision is imported.

Thanks to everyone who tried to help!