Hi,

I'm trying to use some proxy pieces to collide with a FLIP simulation but can't get them to work properly, they create artifacts when using them as a group. The pieces already have a vdb collision, have velocity computed and work well when using them individually but there is some problem when trying to use them at once.

The collision guide in the FLIP object node doesn't show any collision but they work so don't know if that's the problem, also just in case I have the bullet setup as convex hull with the create per set or primitives activated and nothing.

I'm attaching a video with 3 different setups, with all the pieces, with 3 and with 1 and 2 screenshots of the pieces setup. If anyone has any idea or has encountered this error would be great to get some help.

Thank you!

I have tested it again using 3 different static objects and works, it's a solution if I reduce the pieces numbers, but would like to know how to make a group of pieces work with a single static object node.

Attaching the video with the 3 pieces with each one as a static object working. If anyone has any idea how to make it work would be great, using Houdini 17.

Finally fixed it, in case anyone has this problem. In my case, the problem wasn't about collision geometry, the velocity on the colliders was incorrect, if you compute the velocity of a collision geometry after deleting any point it creates velocity spikes, just compute the velocity before modifying the geometry. Using a single mesh was fixing it because there were just one geometry so the velocities were correct.