Force UE to use my custom UCX Mesh for collision

Is there any way to force UE to use my custom collision mesh?

Its a simplified screwthread that im using for a worm gear.

I made it for a physics simulation so it has to be a “simple mesh” otherwise I would use it in the complex channel.

It imports fine with my model, but UE tries to decompose it into its own shapes and makes a total ■■■■ of it!

I have had to decompose it myself into simple blocks before import and this does work to a degree, but its very sensitive to jamming up the simulation because its in lots of disconnected cube like blocks, It would be better if it was a single continuous surface as i drew it, but UE wont take it as it is.

Can I override UE decomposition of my UCXmesh and just use it as it is?

UCX doesn’t meant you can import Anything.
here is the doc reference:…hes/index.html
here is the image that goes with it.
you have to construct many separate UCX meshes to create a threading of a screw.
each loop should be it’s own separate convex hull. They should appear to be something like this


For them to be valid UCX.

Is it necessary to have the < parts in the collision?
if it isn’t, then obviously a cylinder would perform better.
if it is, unfortunatelyz the circular portions are the only way I can think of to get it to import correctly.

Ps: why are they affecting the simulation though? The collision parts of a single object do not move unless you somehow created a PHAT asset or something the like for it.

thanks for the info. its a steep learning process…i was just trying to make this work, the worm gear at 20 seconds. it worked eventually once i worked out what ue was doing and how it decomposed my ucx mesh. its a shame it cannot be told to just use the ucx mesh though. i basically chopped the ucx mesh into 15 degree sections throughout the thread and it imported ok after it did its stuff.