Hello. I just want to understand, what’s for this parameter in skeletal mesh settings:
I’ve tried to google it and the only thing I’ve got is this (and I didn’t understand it):
By default, Unreal will use the collision volumes in your SkeletalMesh’s physics asset to calculate collision.
When you Enable Per Poly Collision, you are telling Unreal you want to use the traiangles of the mesh to calculate collision.
This is a more accurate method of calculating collision, since Unreal will be using the actual mesh vs an approximated collision volume, but it is also more expensive.
Most times, you do not need to enable it, but it may be necessary or desirable in certain situations, depending on your specific project’s needs.
If I’m using it for cloth simulation, can I just disable physics asset and use this option instead?
Is this for real-time cloth simulation inside Unreal or will the simulation be interacting with anything in real-time?
If it’s prebaked and brought in, then you don’t even need collision. Both collision solutions (Phys Assets and Per Poly) are only necessary for real-time collisions.
If it will be interacting with objects in real-time, then use the Per Poly Collision if you want accurate collisions on the surface of your cloth.
It’s real-time cloth simulation for my character. And for now I’m trying to set it and there is always a problem with collisions. My dress going through character’s body everywhere, and the only way I found is to use level set for accurate collision, but it requires too much performance.
Unfortunately, that’s the trade-off. It has to calculate for each polygon of your mesh, leading to slower performance.
So, your options are to reduce the number of polygons so that there aren’t as many calculations, or create a more accurate Physics Asset.
If you want to give the polygon reduction a quick test, you could try using Unreal’s SkeletalMesh LOD settings to quickly get a lower polycount mesh and see how much it improves performance. Depending on your results, you may want to use the lower polycount mesh or rework your mesh in an external DCC and target whatever polycount you got good performance with.
The other option is to add collision volumes to your Physics Asset so that the collision is as close an approximation to your mesh as possible. Start in the areas where you see very obvious clipping with the clothing and do tests. Then add more collision as needed.
Well, I suppose this is related to my another question, but my collisions from physics asset doesn’t collide with clothes at all. So I looked for a more easy way…
I haven’t done a whole lot with Cloth Simulations specifically, but looking around, there seem to be Cloth specific flags to enable collision.
This short video mentions some, maybe these can help? How To Add Collision To Cloth Simulation In Unreal Engine 5 (Tutorial)
Yes, I’ve seen this one and much more anothers videos. But thank you anyway.
