Freeze when activating cloth self collision

[cam.crichton]

Max freezes up when turning on this option in the cloth collision rollout. I have an NVIDIA RTX3060 running latest Max and TyFlow

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Now it is freezing when turning on Enable CUDA collision solver

[cam.crichton]

I should mention that the CUDA dll's are installed

[cam.crichton]

So CUDA refuses to work - how do I get cloth collisions without CUDA?

[tyFlow]

If you post the file I can check it out, but the CCCS isn't really meant to work with tets.

For tets you'll want to use regular Particle Physics collisions...if you open the official tets example file you can see how I've set that up.

[cam.crichton]

$750 for a pro license just to get this feature that doesn't work! Are there older versions available that work without CUDA?

[tyFlow]

What exactly are you trying to achieve?

Tets are for specific types of soft body sims that don’t require the CCCS. The sim will still be GPU accelerated in the PRO version, it just doesn’t need that solver that’s designed for planar cloth sims (sheets, cloths, paper, etc)

[cam.crichton]

If you post the file I can check it out, but the CCCS isn't really meant to work with tets.

For tets you'll want to use regular Particle Physics collisions...if you open the official tets example file you can see how I've set that up.

The tets sample file is the one I am using to test. The result is self intersecting. I want to use this method for an effect but I need it to not intersect itself.

I have added a cylinder to collide with the test - everything looks very encouraging for a proof of concept, except the self intersection.

What method do you recommend for this sort of effect?
   

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running the same test on the tetTear doesn't seem to intersect because they are pulled away from each other but the sphere when it tears, the halves bounce back into each other and there is no self collision

   

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Also - this is only one component of the effect. The effect is a bullet impact - I want to realise the fleshy part using tets. I am planning to run a cloth sim over the top to replicate the skin. The skin will definitely require self intersection on cloth.

Can you please provide any instruction on getting the Cuda solver to work?

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OK, cloth solver working with cuda 11 dlls but freezes when turned on with tets in the flow - got it.

Tets self intersect and I will look for a solution for that.

[tyFlow]

The CCCS is freezing on tets because in their default state tets perfectly overlap with each other. This is what you want for normal tet dynamics, but not what you want for the CCCS, which requires cloths to be non-intersecting/overlapping on their starting frame (the "freezing" is basically an explosion of compensatory forces trying to separate faces with zero distance between them - 'divide-by-zero' in cloth-solver terms).

To prevent self intersections on tet softbodies you'll want to use Particle Physics and a small time step. Basically treat it the same way normal cloth self-intersections used to be treated before the CCCS was introduced.

Improving tet dynamics has been on my mind for a long time, and PhysX 5 (recently added to tyFlow) has its own tet solver for softbody dynamics. So there's lot of room for improvement in the future, although I don't have a timeline in mind currently.

If you describe your bullet impact scene a bit more I can try to offer further advice for setup. Is this like a closeup of a bullet tearing through organs or something?

[cam.crichton]

It is a slow motion close up of a bullet impacting an animal. There will be a layer of bone to fracture, a layer of tets jelly moosh for the fleshy stuff and a layer of skin. I have an added complication of yeti fur which shouldn't be an issue as long as I can maintain UV's on the skin. And some Phoenix fluids for good measure.

I started this out in Maya but after seeing the tets and having used tyFlow before I jumped ship to Max.

[tyFlow]

If you shoot me an email with your scene/setup, I'm happy to take a look and give you some advice on how to get something like this set up. Or you can post here but I'm not sure if it's something you want to post publicly. Either way, from the description it sounds like tets would indeed be a good solution for the jelly. The CCCS on the tets itself (inter-tet collisions) won't work, but it could potentially be used to achieve good collisions between the jelly (tets) and the skin (regular cloth).