Modify Constraints during Bullet-Simulation

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…in detail, i, for now, simply wanted to remove some glue-constraints near the ground, using a static bounding box, with a SOP-Solver.

Tried a vast number of settings and methods (both in the Bullet-Dop and the Glue-SOP), but can't access the sim-driven “live”-movement of the constraints, attached to the packed geometry.

In the hipnc-file, there is a very basic setup, without any changes, i made during rnd.


Furthermore, is there a way to get some usefull attributes like impact/collision/stress/… of the constraints in DOPs, for breaking in a more physically based way? Especially while Simulations are running, so a more dynamic approach?

I'm relativly new to Destruction in Houdini, came from Thinking Particles (3dsMax) and try to understand the possibilities and workflows.

Thanks and cheers

Attachments:
constraints_02.hipnc (240.8 KB)

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https://www.sidefx.com/tutorials/controlling-your-fractures-in-houdini/ [www.sidefx.com]
https://www.sidefx.com/tutorials/houdini-dynamic-fracture/ [www.sidefx.com]

hope that's helpy
English is not my native language, sorry in advance for any misunderstanding :-)
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Thanks Matthias,

i'll have a look.
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…so i watched the “Dynamic Fracture” Tutorial, but it seems to not exactly solve my problem. Also the Pluralsight-Tut is more about static fractured Geometry, i think, by what i've seen in the Trailer (don't have a Pluralsight Acount yet).


In the “Dynamic Fracture” Clip, the constraints follow the Charakter-Deformation, so it happens before the Simulation in the SOP.

What i wanted to achieve, was to pickup the movement of the bullet sim. For Expamle:

- A Building Collapses and as the Pieces fall down (Constraint Groups of Fractures) the glue dissapears, for example near the ground or on impact (or some other conditions).

I can't get the “live” positions within the DOP to modify the constraint-Properties “on the fly”.
Normally the Glue is build on the First Frame but even if i kick the Timeshift, it doesn't update in the DOP-Network (Sop-Solver). Also tried different setting-combinations with the SOP-Overwrite, etc…

Lately, i tried to import the Bullet-Sim-Movement into the Glue-Constraint-SOP, offset the Time by one Frame, did a pointdeform on the Glues and reuse on the same DOP as before, but with no Luck or got some realy weird Effects.

I hope i explained my problem properly and don't overlook some simple solutions.
Edited by vertexunited - Oct. 9, 2017 07:02:33
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Quick explanation of the changes I made: changes Object mask in dop_geometry to “1”, because thats the id of the rbdpackedobject (looked it up in spreadsheet). then added an attribute wrangle to update the point positions of the constraints via name attribute. note that I removed the “rbdpackedobject1/” component that was in the name of the fractured geo originally.

Cheers.

Attachments:
constraints_02.hipnc (245.8 KB)

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