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Simulate MPM node out_colliders

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Message 1 of 11
davide445
620 Views, 10 Replies

Simulate MPM node out_colliders

Was trying to use this connector to display the colliders shape in my sim.

So far tried to connect it both to a specific output or to the graph unique output.

I didn't see anything new on the render view, so wanted to ask if anyone has used it or has guidance about how is supposed to work.

davide445_0-1628859960678.png

davide445_1-1628860010142.png

 

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10 REPLIES 10
Message 2 of 11
michael_nielsen
in reply to: davide445

Hello,

The render view does currently not support colliders (and level sets in general) output directly from Bifrost.

If you don't see the colliders in the viewport it is most likely because the MPM voxelization of colliders may not voxelize the colliders if there is no mpm material nearby. If you switch the "Method" port on the collider node from Automatic to Volume you should be able to see the colliders in the viewport.

If this does not help, please attach your scene file if possible.

Cheers,

Michael



Michael Nielsen

Principal Engineer
Message 3 of 11
davide445
in reply to: michael_nielsen

Hello

I tried last week to use the Volume colliders method but in fact this disable totally the collider.

From the documentation seems the Volume method it's not compatible with MPM sim, but I see many elements missing in the doc so I will be not surprised if I needed to consider somerthing else to make it work.

Can send you the file in PM if needed.

 

Message 4 of 11
michael_nielsen
in reply to: davide445

Hi,

At least for the snowball throw example, the Volume method works. If your collisions do not work with this approach it might be that it's an issue with the geo detail size, you can try to experiment a bit. And feel free to send a scene file as a PM if you can't get it to work, then we can have a look.

If you have ideas or suggestions for how you would like to see the MPM documentation improved please let us know, then we can address it.

Cheers,

Michael



Michael Nielsen

Principal Engineer
Message 5 of 11
davide445
in reply to: davide445

Hi

re-testing with:

Collider: Volume method, checked the Optimal adaptivity option

Source: checked the Optimal adaptivity option

Solver settings: lag collider enabled

 

In the documentation is missing:

- source_mpm_snow: there is no mention of the optimal adaptivity flag

I think a few things in the doc was added in the meantime since I remember, better so or I was remembering wrong.

Message 6 of 11
michael_nielsen
in reply to: davide445

Thanks for the suggestions to the documentation. I will forward this info.

 

Do I understand correctly that your scene is working now with the settings you listed?

 

Cheers,

Michael



Michael Nielsen

Principal Engineer
Message 7 of 11
davide445
in reply to: davide445

Hi Michael

 

I run a batch sim with these settings but didn't see anything in the final render about the collider shape.

My problem is I didn't find any documentation about what I'm expected to see using this connector: need I to run a sequence render and look at the Maya viewport instead?

 

thanks

Davide

Message 8 of 11
michael_nielsen
in reply to: davide445

Hi Davide,

The colliders output will not show up when rendered with Arnold at the moment, but it should show up in the viewport (on my side it does). The colliders output is mostly for debugging collider interaction. For final renders I would recommend to use the input geometry directly. I will make the docs team aware that this is unclear.

Cheers,

Michael



Michael Nielsen

Principal Engineer
Message 9 of 11
davide445
in reply to: michael_nielsen

Hi Michael

 

further testing and running the simulation in the viewport I didn't see any collider.

Since I was never able to find any example, can you please post how is supposed to appear out?

Also, just to be sure, in the Bifrost graph I'm supposed to connect the out_collider to his own ouptput, to the global graph output (the same I'm using for the MPM sim) or something else.

Message 10 of 11
davide445
in reply to: davide445

In the end I was able to see it: just connecting out_collider to his own output node and running the sim in the viewport using hardware rendering, the collider it's the grey shape.

His shape it's not what expected, but this is another problem.

Collider 4_2.jpg

Message 11 of 11
michael_nielsen
in reply to: davide445

Good to hear you were able to visualize the collider.

It's hard for me to see exactly what's wrong with the collider from your image. It could look like maybe it is not a closed geometry. In that case you would need to experiment with the 'hole radius' or the 'shell' parameter on the collider node. Experimenting a bit with the detail size might also work.

If you're unable to get it to work, please feel free to share your scene so we can have a look.

Cheers,

Michael



Michael Nielsen

Principal Engineer

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