Fixed: Bullet Physics - Update Collision Shape crash with letter instance

Hi,
I’m using the Bullet Solver to animate letters who change in size overtime.
My project is crashing whenever I decide to update or add text.
I figured that the source of the crash is the Update Collision Shape who is set to On so I can scale the collision shape with my instances. When I change my text the project will crash after few seconds.

I’m using TouchDesigner.2021.14360 on Windows 10 Pro

I have a dump file but I’m currently not authorized to share file in the forum :confused:
[TouchDesignerCrash.2021.14360.22.dmp|attachment]

Thanks for the report. Send an email to support@derivative.ca with your toe and dmp file and we’ll take a look into the crash.

Email sent !

The crash was due to having infinitesimally small collision shapes in the simulation (when the letters were shrinking / phasing out), which the Bullet Physics API doesn’t handle very well.

I got around this problem by automatically deactivating bodies once their collision shapes get smaller than a certain threshold. They will no longer be counted in num_active_bodies and in the Bullet Solver CHOP active channel their sample will be 0. The bodies will automatically be reactivated if their collision shape size increases beyond the threshold.

A fix for this is now posted in Official 2021.15020