# Hard Constraints Problem - Force Reaching Infinity

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Hey there odforce!

Right now I'm trying to do a destruction simulation on a spaceship that I made, and I'm running into a problem that I can't seem to figure out.  If anyone is familiar with Steven Knipping's Rigids III, the general setup is based off his approach.  Here's some quick info on what I'm doing:

*  I'm simulating the spaceship destruction with bullet/packed primitives

*  These packed prims are a mixture between voronoi shattered pieces and unshattered geo pieces

*  Even when the spaceship is standing still, forces on the constraint prims will reach infinity once simulation begins

*  In DOPS, I've made a SOP solver that breaks my hard constraints once it reaches a certain force threshold, and since things are reaching infinity, it's basically just destroying all my hard constraints within a few frames

Here's the ship:

Here's the constraints using connect adjacent pieces from surface points with default values:

After a few frames of simulation, it turns to dust =/

In dops, force is shown to reach inf and breaks the constraints based off my attrib wrangle which says...

f@superHighNum = 100000000;

if(f@force > f@cat_hard_break_force && f@cat_hard_break_force < f@superHighNum){
@group_broken = 1;
}

where f@cat_hard_break_force is the force threshold that I define

I tried countering this behavior by adding the f@superHighNum, but it looks like forces gradually reach infinity, so it still breaks...

Has anyone encountered this sort of issue before?  If so, what might cause these forces to reach infinity?

Here's a few things I've tried:

* Cleaning up the mesh and fusing points before connect adjacent pieces

*  Setting rest length to zero

*  Blasting funky looking constraints before simulation

*  Trying a bunch of different settings on connect adjacent pieces when generating the constraints

*  Simulating with glue constraints to see if forces still reached inf (they do not reach infinity with glue)

*  Increasing the constraint force mixing parameter

*  The RBD physical properties are at default values

Also be sure to check out Steven's tutorials because they're really awesome.  I couldn't find his e-mail to ask about it, but perhaps you guys might have some ideas?

Any thoughts, theories, ideas, would be greatly appreciated, thank you for your time!

-  Tyler

ssGainz_v011.hiplc

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Seems like you have some issues with collision geometry, try to display  collision geo in rbdpackedobject at dop level. If you don't see issues try to decrease shrink value for collision geo, usually it is 0.02 try may be 0.001 ( depends on size of you ship ).

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@tbay312 I still don't know why its reaching infinity but I have found that if you add an "Enable Solver" DOP right after the SOP Solver for the constraint network, and make it so its inactive until the rigids become active, it seems to give you your control back.

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