Forums Technical Discussion ODE solver on Shatter Objects?

ODE solver on Shatter Objects?

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artzor
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Title says it all…

Is it possible to use an ODE solver on multiple objects coming from one sop?

ie, a hundred cubes grouped individually, would normally just use a RBD fracture object in dops but that doesn't seem to work with ODE…

any ideas?
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jacob clark
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Hi Artzor,

This is a file I got from SESI on the matter. Hope it helps!

Attachments:
Debris_v0001TOSESI_moved.hip (1.5 MB)

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artzor
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thanks jacob, that's a very handy demo file.

so the basic workflow is:

- create objects
- make sure they're grouped
- use `bake ODE` which creates a point per group
- bring that sop into dops
- use an ode configure (set to composite) and and ode solver…

seems great, but it just doesn't seem to work for me….?

two other queries are, how do you get the original geometry back onto those points?
(just copy or instance i assume…?)

and, sometimes the bake ODE sop just doesn't create points… but it creates the attributes and groups it needs. very strange.

thanks
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jacob clark
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Hi Artzor,

That seems to be missing some steps.
For instance re-grouping the objects in SOPs
Make sure to pay attention to the comments in the SOP network.


To bring the geo back to SOPs, a objectMerge SOP is probably simplest.


cheers,
-j
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artzor
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“We stamp spheres to the odePointGroup so that those points will belong to a primitive group piece#, otherwise if they were free floating we wouldn't extract them when we do our fracture.”

i checked out all the sop steps and repeated them,
so now the ode point groups and geometry primitive groups are retained

but still the sim doesn't run, ie, nothing happens

any chance anyone could get this working with say, two cubes, and without any foreach stuff. just for simplicities sake..

thanks very much

Attachments:
ode_test_v02.hip (98.5 KB)

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jacob clark
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Hi Artzor,

Having a look at your file, you are almost there.

The one missing bit, is your spheres with the ODE attributes are not in Primitive groups.

I put a quick expression in the Create Groups field on the Copy SOP to fix this.

Should be good to go!

cheers,
-j

Attachments:
ode_test_v02_190.hip (122.1 KB)

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artzor
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aaah, thanks jacob

works great now.

so that step is converting point groups into prim groups?
(seems a bit abstract to me)

now i must just have another look at bringing the sim back over to the original geo

thanks!!!
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jacob clark
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Hehe, you're right! It's not the best way to do it.

When you get a good workflow going let me know, so I can steal it!



cheers,
-j
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