topic Re: my MASH dynamics objects is passing through the bullet solver ground in Maya Dynamics Forum

my MASH dynamics objects is passing through the bullet solver ground

SouuGui_ — Wed, 10 Feb 2021 02:10:28 GMT

hello guys,

I'm having a problem that can't solve by myself. I set a MASH network and added dynamics node to it, but when a press the play button the objects start to fall and pass through the bullet solver ground.

I checked all debugging boxes to see if I could find out what was wrong however and i didnt understand what it showed me, I'll attach a playblast highlighting the ReproMesh and a screenshot of the ReproMesh

Thanks in advance,

Hope you're all safe and health

Re: my MASH dynamics objects is passing through the bullet solver ground

hamsterHamster — Wed, 10 Feb 2021 12:24:44 GMT

Increasing BuletSolver's calc rate does not help? Internal Frame Rate to start, then Collision Iterations, and for the last resort Collision Margin -- will be slower, but more accurate.

Re: my MASH dynamics objects is passing through the bullet solver ground

SouuGui_ — Wed, 10 Feb 2021 22:51:28 GMT

I tried everything you said and nothing happened =(

It feels like there's a force field or something pulling the objects to it, but I didn't add anything like that.

I tried to add collide objects but the pills just pass through them like they do to the Ground

Re: my MASH dynamics objects is passing through the bullet solver ground

hamsterHamster — Thu, 11 Feb 2021 12:45:19 GMT

From what I found, the Preferences>Animation>Evaluation:Paralel setting might be the cause. Yet, see if it helps when you change it to DG. https://forums.autodesk.com/t5/maya-dynamics/maya2018-mash-dynamics-deforming-mesh-collisions-not-solving/td-p/8202454

Re: my MASH dynamics objects is passing through the bullet solver ground

SouuGui_ — Thu, 11 Feb 2021 14:09:09 GMT

Unfortunately nothing happened when I did that 😭😭😭

I attached the .ma file if you feel like looking what's wrong

I'll keep looking for the solution, if I find it, I drop it here

Re: my MASH dynamics objects is passing through the bullet solver ground

hamsterHamster — Thu, 11 Feb 2021 20:04:38 GMT

Ok, you are working in M2020 Student, maybe something was missing when loaded in M2019. And this is my first time with MASH, therefore something of what I suggest might be unnecessary.

So....actually a lot is going on there.

To see why no collisions, turn on BulletSolver>Debugging>Colision Shapes - you have translated pills away manually and collisions are about to happen ..Elsewhere 😄 - looks like nono for me.. And that is just a small fraction of why..

1. Bullet solver transform - reset back to origin (turn back Grid display!), scale 1.0. You don't need floor collider because you have solver's Ground (changed to 0,0,0);

2. main_pill group - rotated vertically, centered pivot, moved back to the origin, froze transformations;

3. Grouped all the geo and lights with pivot point to the floor plane's center and snapped to the origin - less negative calculation values;

4. To speed up sim decreased _Distribution grid to 5x5x5, change back to 8 once you are happy;

5. Added mash_Transform for pills, in Translate entered 100,480,-210;

6. Added mash_Random for pills to randomize rotations.

7. After experimenting with _Dynamics solver I ended up with such ConvexHull shape, and 1.3 scale.

8. You have to set the pipe collider to shape>MASH>Mesh. Even it was done, the bullets still passed through, so I applied meshSmooth several divisions, reversed normals, deleted history, and froze transforms for scale.

9. to speed up sim, ReproMesh Level of Detail can be set to boundingBox, activated UseGPU.

That was it.

Re: my MASH dynamics objects is passing through the bullet solver ground

SouuGui_ — Sat, 13 Feb 2021 01:49:45 GMT

wow, there was a lot of details I didn't notice I messed up, I can't thank you enough for giving your time to help me out, it was a great lesson to me.

I read everything you sad carefully to get it all, but I have some doubts:

1. Bullet solver transform - reset back to origin (turn back Grid display!), scale 1.0. You don't need floor collider because you have solver's Ground (changed to 0,0,0);

What do you mean by scale 1.0?

7. After experimenting with _Dynamics solver I ended up with such ConvexHull shape, and 1.3 scale.

I didn't understand this one

The other topics I understood and will change already.

Again, thank you so much for your time.

😀

Re: my MASH dynamics objects is passing through the bullet solver ground

hamsterHamster — Sat, 13 Feb 2021 10:02:28 GMT

1. Your pills_BulletSolver has scale 43.003, I scaled it back to 1.000

7. pills_Dynamics (see in MASH Editor) has Collision Shape and Collision Shape Scale.. what worked for me was Convex Hull type and 1.3. I believe it would have worked with other combination too, yet this seemed to have most precision for pill shape.

Re: my MASH dynamics objects is passing through the bullet solver ground

SouuGui_ — Sat, 13 Feb 2021 13:48:39 GMT

Ohhh I see,

Thank you so much, now I get everything and will apply

Have a nice weekend!

Re: my MASH dynamics objects is passing through the bullet solver ground

raularosemena — Fri, 29 May 2026 05:55:20 GMT

I was having the same issue, the Collision works if the object is not moving on DG, but when you add keyframes the collision object it need to be in Parallel Evaluation, so Thank You!