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MPM Cloth is very Slow or what?

Message 1 of 14
1179 Views, 13 Replies

MPM Cloth is very Slow or what?

Hey guys,

just trying to setup a simple scene with bifrost, using MPM Cloth simulation,

everything is simple and the polycount of cloth isn't high either,

but the simulation is just too slow, its as slow as nucleus or even slower, it takes almost 2S per frame.

is anything wrong with my setup? any advice? 

my cpu is i7-5820K 3.3 GHz 6 core(12thread), 64GB RAM.

Message 2 of 14

Its a MPM solver. Its made vor quality.


But please upload your scene so we can take a look if its working like it should.


Edit: I see you have your scene attached. Thanks.


Message 3 of 14

There are some experimental nodes in your graph. Noticeable on the little orange icon.

Those nodes arnt optimized/final yet. They should get faster in a future update.

Message 4 of 14
in reply to: HasanDiab

One thing to try is lowering the Detail size a bit (currently at .015 on the mpm_solver_settings node) by increasing the value (I tried .03). You lose some accuracy but you have to establish if you really need that accuracy or not. 


But yes, there is always room for performance improvements.

Message 5 of 14
in reply to: syracoj

Strange, every other Detail Size than 0.015 and the cloth disappears.

Message 6 of 14
in reply to: Christoph_Schaedl

it may be because I have latest greatest.

Message 7 of 14

It happens to mee too, i though maybe its a bug or i did somthing wrong 🤷‍:male_sign:

Message 8 of 14
in reply to: HasanDiab

Hey Hdiab,


When I opened up your scene a couple of the nodes were in a bad state so I had to rebuild the graph. After I did that I was able to change the detail size.


I'm going to go through the scene and workflow again a second time though just for the sake of thoroughness. 

Message 9 of 14
in reply to: HasanDiab

We have fixed an issue cloth disappearing during a sim but it wasn't directly related to changing Detail Size.  Would those of you who are experiencing this, upload a file.
I tried lowering the Detail Size on Hdiab's cloth file without reproducing but would like to get as many example file to check the fix against.  Thanks.

Message 10 of 14
in reply to: syracoj

Maybe because u r using an earlier version, i built this scene in maya 2020, if u try to open it in 2019, it will give some bade state nodes

Message 11 of 14
in reply to: wongt

Didnt try it with the latest version of Bifrost graph, i will update bifrost, retry it, and give u a feedback.

Message 12 of 14
in reply to: HasanDiab

The fix has yet to be released.  I will continue to try it out internally against the file you uploaded.

Message 13 of 14
in reply to: HasanDiab

yes double checking on my side reveals proper operation.

see attached image



Message 14 of 14
in reply to: syracoj

yes, that is because you have rebuilt the graph,

the problem was in the mpm_solver_setting->max steps property was set to 20, I reset it to 1000 and it worked just fine, but slow as I Mentioned before.

I really didn't understand yet how every property affect the graph and the simulation!

I think bifrost graph needs more documentation or maybe tutorials that covers most aspects and how it works and interchange data and properties with maya.


And by the way, I want to thank the team behind this wonderful peace of software ❤.

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