UCX collision convex hull broken
Hello, I'm trying to set up some UCX collisions and worked somewhat good so far but when I tick the "One convex hull per UCX" checkbox, the collision breaks and spreads vertices all over the place. Without this box checked the collision gets avaraged and I lose some information there but fits the object reasonable well. Am I modeling the collisions wrong? Thanks in advance
Yep, your collision normals are inverted. I just spent hours banging my head against the wall trying to figure out the same exact issues. Now that backface culling is disabled by default in Maya, you need to ensure that you have your normals facing the correct way or else it'll do the same spiking.
Also another trick you need to look out for is that your collision mesh has to be watertight/one solid piece. If you have holes in the mesh that expose normals without sealing them it will cause this issue. You can have multiple pieces overlap, but they all have to be 100% sealed.
I've been trying to reproduce this and I've managed to get it in a much smaller scale and with the one convex hull per ucx unchecked, which can be expected depending on how the collision is setup.
For an object like this you could always use the in editor generated collision by using the auto-convex solution and adjusting the max hulls and max hull verts to get something similar.
There will be a change coming in a future release to make collision generation better for more complex objects. Unfortunately, no eta for that other than "Soon."
I am really interested in getting the spiking results you get with yours. Would you be able to share an asset that gets this kind of spiking so I can take a better look and see if I can get a repro? If you're willing you can post a link here or send one privately to me via a forums message.
answered Feb 12 '15 at 09:41 PM
Tim Hobson ♦♦ STAFF
There's a very good chance your Collision Normals are inverted.
answered Nov 23 '15 at 08:58 PM
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