Buggy behavior RBD Glue Object and Glue Adjacent

   6860   4   0
User Avatar
Member
4 posts
Joined: Oct. 2012
Offline
Hi,

I've ran into this problem in several of my setups. I'm starting to think this is a bug rather than me just being ignorant. Can anyone confirm?

Quite often I get these odd bits left hanging in the air glued to the “parent” static rbd object when they clearly should fall down freely. I've tried with the RBD Glue Object and the Glue Adjacent methods with similar results. Have a look at the attachments.

Any ideas or workarounds?

Cheers,
Kari

Attachments:
buggy_RBD_glueConstraint.hipnc (303.0 KB)
buggy_RBD_glueObject.hipnc (292.9 KB)

– Kari
User Avatar
Member
109 posts
Joined: June 2008
Offline
Hi,

in the first file, i was able to get it working by reducing the Glue Strength (box_active-node) to 10
User Avatar
Member
4 posts
Joined: Oct. 2012
Offline
Thanks for having a look! That indeed gets around the problem but it does change the look and feel of the sim. In my actual setup I'd like to keep things relatively hard to break. Was hoping to find a way to “release” the orphaned shards. No idea how to do this though…
– Kari
User Avatar
Member
19 posts
Joined: April 2009
Offline
are the constraints broken ? You could bring your glue polygons into a sop solver and delete the ones that wont break on the frame you'd like .. hacky but should work .
User Avatar
Staff
329 posts
Joined: July 2005
Offline
kbrown
Quite often I get these odd bits left hanging in the air glued to the “parent” static rbd object when they clearly should fall down freely. I've tried with the RBD Glue Object and the Glue Adjacent methods with similar results.

There are two different types of glue system understood by the Bullet solver: RBD-style glue and the Glue Network Constraint-style glue. The two glue systems have different behaviour. With the RBD-style glue, a piece needs to be directly involved in a collision to be released from the glue parent (this is why some pieces remain glued to “box_passive”). With the Glue Network Constraint-style glue, glue bonds further away from the location of the collision can be weaked and release (see the “Impact Propagations” and “Propagation Rate” parameters).

kbrown
Any ideas or workarounds?

Consider replacing the RBD-style glue in your simulation with Glue Network Constraint-style glue by clearing the “Glue to Object” parameter on the /obj/AutoDopNetwork/box_active node and adding “box_passive” to the “Object Mask” parameter on the /obj/glue_piece1_to_piece9/fetch_objects_to_glue node.
  • Quick Links