Need help from any RBD experts.
I have the correct setup now for using Convex Decomposition for proxy geometry but my animation after collision seems wildly erratic.
It's as though my geometry has no mass-inertia.
Can anyone suggest what might be happening? Pretty sure it must be a RBDBulletSolver setting but so far haven't been able to fix.

The RBD Material Fracture SOP has a built-in convex decomp option (run on the hi-res geo and output as proxy).

You're doing the convex decomp on the hi-res geometry (first geo stream). The RBD Bullet Solver will use the proxy geo (third input) if it has any geometry, so everything you're doing to the hi-res geo is being ignored. Plug the assemble1 node's output into the RBD Bullet Solver's third input or disconnect the third input to the RBD Bullet Solver.

You have a warning on the RBD Bullet Solver - what does it say?

Have you checked the simulation geo? RBD Bullet Solver > Visualization > Geometry > Show Collision Shape

Bullet struggles with really tiny pieces. If the collision geo is too small, you can play with the RBD Bullet Solver > Properties > Pieces > Collision Padding and reduce it there. If you only want to reduce the collision padding on some pieces, you can do that using a RBD Configure SOP.

check the advanced tab, constraints values and type can be causing it.
check the collision padding inside the properties tab and make it to default, if it is high. it can be the problem
edit 2 uploaded the sample file replicating the sim. yeah as npetit said the poly reduce and the convex decomposition goes into the proxy input


I dont think u miss some attribute or miss match of attribute and causing issue from transform pieces.
I hope u will find out the solution after going through the simple file replicated setup.