Enable collision per Axis

Hi !

Still working on our car, we have a little problem concerning collisions for the wheels. The thing is we need to use sphere collisions on our wheels, otherwise the car is not stable (Convex collisions for example). Therefor, the body of the car never enter in collisions with walls, because the wheels touch it before the body.

I have two questions :

  • Is it possible to enable per Axis colisions, because I need them only on Z

OR

  • Is there a way to get a cylindrical collision with Skeletal Mesh or Static Mesh (I can change my wheel type to static of needed).

I have already tried the Copy Collisions from static mesh, but it gives a convex results, therefore making the car unstable.

Thanks for anyone willing and able to help me out !

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You can mess around with the collision filtering of the various objects of your vehicle. For examble, change the ObjectType of the walls to WorldStatic (or other not used by the ground) and set the response on your wheels to Ignore WorldStatic. For more detailed information have a look at this doc.

Yup… I think I will go with this solution then. It’s sad to not have proper cylinder based collision, even tho I read that it is performance heavy, and not as easy as it seems with PhysX, but still, would be much more simple for vehicle !

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Yeah, already tried the custom UCX, but even with a highly divided cylinder, it does not work well (car get bumpy at 70KM/H & more).
Capsule aren’t the answer either, because scaled to 0, they give a sphere, and scaled negativly, they give a sort of cylinder, but this is glitched as hell…
Filtering it will be then ! Created a custom channel, so the wheels only collide with this one.

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You can have cylindrical collision by importing your own UCX with your wheel meshes but yes, it won’t be perfect unless you give it a lot of sides, in which case it won’t be as performant… You can also try a Capsule collision but the overall problem you will have with non-spherical colliders is that you will need way more torque to compensate for the increased surface area that’s making contact with the ground.
Please mark the response as answer if it helped ya :wink:

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I am having the same issue, did you ever get this figured out?