I've tried and failed for a while now. That's why I'm looking for help here.

I have a super simple setup. A fractured cube - fractured using rbd material fracture.
I use the rbd Bullet Solver SOP to let the fractured cube fall onto a ground plane and shatter.

Now I simply want to access all the pieces that had their constraint broken and remove said piece. Is there a simple way I can achieve that using a geo- or pop wrangle or similar?

My problem seems to be accessing the constraint information for each piece/point, and checking the state of the constraint.

A nod in the right direction would be much appreciated.
Cheers!

it's relatively simple, but to avoid too much code, you have to do 2 things (it's possible to do all in 1 wrangle with more code if needed)

1. delete broken constraints (as they are not removed by default during sim)
- Bullet Solver SOP/Contraints/1/
Constraint Names: Glue
Use VEX Snippet: On


2. check if the current piece has any constraints left and if not delete:
- add POP Wrangle inside of Bullet Solver SOP
- set Inputs/Input2/DOP Data: ConstraintGeometry

Thank you tamte! That was very helpful.

I managed to do it in Houdini 19 and achieved the effect I'm after.

Using a Geowrangler running over the ConstraintGeometry, I removed the detached Constraints.

Then using a Popwrangle I deleted the points/pieces without a corresponding Constraint.

Changing the Houdini version from 18 to 19 did the trick. Somehow in 18, I cannot access the ContraintGeometry using the DOP Data Input.


In 19, as soon as I check "Use this Object's Data", I can access the Attributes on the ConstraintGeometry.


In 18, that does not seem to work and there is no checkmark available. What am I missing?

I still work primarily in Houdini 18 so getting this setup to work there, would be quite helpful.

Cheers

in H18 try using
since it doesn't have checkbox to Use This Object

that's it! thank you