For some reason I am having a difficult time constraining RBD objects to animated geo. I have done this in the past inside dops, but am trying to do it in the new RBD workflow.
I am fracturing a box and then successfully creating constraints to static ground geometry. I am then replacing the static ground geometry after creating the constraints with the animated one, and using the rbdconfigure to make the animated ground non-active, animated, and deforming while keeping the fractured box with the default settings. My animated ground is moving as expected in the sim, but it doesn't look like the constraints are moving the box with the ground's animation. Is there something I am missing?

I have attached a simple scene explaining what I am referring to.
Thanks in advance for the help.

Hi Tyler,

Unfortunately, the way you have wired this up, the ground ends up being deforming geometry and thus does not have any implicit transform updates to drive the constraints.
It's also not the most efficient way of setting this up - deforming RBDs can be quite expensive.

If you apply the transform to the ground proxy geo after the RBD Configure SOP, and only set the ground to “animated”, not “deforming”, the box will move with the ground.

hmm…thanks for the tip @npetit…

npetit
Hi Tyler,

Unfortunately, the way you have wired this up, the ground ends up being deforming geometry and thus does not have any implicit transform updates to drive the constraints.
It's also not the most efficient way of setting this up - deforming RBDs can be quite expensive.

If you apply the transform to the ground proxy geo after the RBD Configure SOP, and only set the ground to “animated”, not “deforming”, the box will move with the ground.

Thanks, yeah I figured out I had to do the transformations after, and then the animation/constraints work. I am actually trying to glue rbd objects to another rbd sim that I already have cached out. However, this doesn't seem to work because the transformations are not simple and require deforming geo, and then the constraints don't seem to stick with the deforming geo.
Is there a better way to do all this? I basically want some geometry to constrain to arbitrary geometry animation.