Hi,
I've got an "animation" that has two objects colliding. Pretend this is from the animation department.
I wanted to take this "animation" and then run an RBD sim on it (for practice). I pretty much got what I wanted, but then the constraints would not follow the RBD objects.
This could be a problem if I was asked to break the constraints below a certain height. How would one go about making sure the constraints update properly?
I have included the file for reference and an image showing the issue. FYI: I have the rbdpackedobjects set to "deforming static objects" and the constraintnetwork has the "Overwrite With SOP" disabled (otherwise it does not work).
Thanks!
Constraints Not Following Deforming RBD Objects
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- TheDude123
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- mrCatfish
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Is this what you are looking for?
I had this issue a long time ago when teaching a similar effect... trying to get a plane to disintegrate when it hit the ground while maintaining the anim for the part of the plane that did not disintegrate.
Key here is to use the extract transform setup to make the geo animated instead of deforming (this is a good trick to greatly speed up any "deforming" geo sim anyway). Also, lock the constraints at the rest frame.
Note the attrib transfer for active/deforming. You could add another for when the cubes hit the ground. Also you can make a more sophisticated attrib transfer where the two objects collide, this is obviously just proof of concept.
Note the bullet solver SOP is unlocked so I could change it to "animated static" geo. This option is not promoted to the top.
Full disclosure, I didn't figure this out myself, Sidefx helped me with the solution.
Sean
I had this issue a long time ago when teaching a similar effect... trying to get a plane to disintegrate when it hit the ground while maintaining the anim for the part of the plane that did not disintegrate.
Key here is to use the extract transform setup to make the geo animated instead of deforming (this is a good trick to greatly speed up any "deforming" geo sim anyway). Also, lock the constraints at the rest frame.
Note the attrib transfer for active/deforming. You could add another for when the cubes hit the ground. Also you can make a more sophisticated attrib transfer where the two objects collide, this is obviously just proof of concept.
Note the bullet solver SOP is unlocked so I could change it to "animated static" geo. This option is not promoted to the top.
Full disclosure, I didn't figure this out myself, Sidefx helped me with the solution.
Sean
Edited by mrCatfish - June 12, 2023 14:23:58
Sean Lewkiw
CG Supervisor
Machine FX - Cinesite MTL
CG Supervisor
Machine FX - Cinesite MTL
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- TheDude123
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Hi Sean,
This is GOLD! I've noticed that "Deforming" objects are MUCH SLOWER in sim. Thanks so much for this tip!
As for the general set-up, I think this is what I was going for. Still need to adapt it to my scene, but it looks like it should work.
Again, thanks so much for taking the time and sharing the knowledge (also to SideFX for the initial help). *respect*
mrCatfish
Key here is to use the extract transform setup to make the geo animated instead of deforming (this is a good trick to greatly speed up any "deforming" geo sim anyway). Also, lock the constraints at the rest frame.
Sean
This is GOLD! I've noticed that "Deforming" objects are MUCH SLOWER in sim. Thanks so much for this tip!
As for the general set-up, I think this is what I was going for. Still need to adapt it to my scene, but it looks like it should work.
Again, thanks so much for taking the time and sharing the knowledge (also to SideFX for the initial help). *respect*
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