Simple cloth sim spins out of control

[MaverickMongoose]

Hi Sassi, I've attached a file with a super simple geometry that I want to sim as cloth. But upon simming in a scene with no forces or gravity it just spins madly out of control.

Adding scene damping helps but I dont want to dampen other objects in my scene which are acting normally. Is it because the geometry is a funny shape? Maybe something to do with the density?

Let me know what you think, thanks again for your help!

problem.c4d

[Dr. Sassi]

Hi Maverick-Mongoose,

I know perhaps too little about your target, but thanks for the file. Here it is back:

CV4_2023_drs_23_SIpn_01.c4d

My first suggestion is in the file, Cloth Tag> Attribute Manager> Mix Animation> Pins 30%. This should allow for some reaction and can be adjusted.

You can have Forces influence it with "Include" or "Exclude" lists of others; just brainstorming here. Friction can also use Fields to limit its reach.

If only object groups are interacting with each other:
https://help.maxon.net/c4d/2023/en-us/Default.htm#html/OPBDSCENE.html?TocPath=Simulate%2520Menu%257CThe%2520Simulation%2520System%257CSimulation%2520Scene%257C_____0

You can set up more than one and define the behavior of each group more. But the groups can interact with each other.

Is there something that works for you?

Cheers

[MaverickMongoose]

Thanks for getting back to me so quick!

I've attached the rest of the scene, I guess I just dont understand why the other objects are behaving as you'd expect, but this particular mesh just goes nuts, like it has some crazy intitial velocity or something.

I think it must just be the particular shape of the mesh that the cloth system is having a hard time with because the other more simple shapes work fine.

I guess I could try your suggestion though and set up a seperate system for just that object, just thought maybe there was a setting somewhere I could use to calm that one down.

Good idea with the Pinning though, that might be the way to go.

Thanks again!

https://we.tl/t-dFiYhQEMf4

[Dr. Sassi]

Thanks for the file, Mongoose.

Please have a look here first: (press play if it is not already playing)

CV4_2023_drs_23_SIpn_11.c4d

You can see clearly what happens here, and that is setting the energy needed for the motion.

.

I have "pinned" the head on its top, so you can see what is happening while the Attribute Manager> Simulation> Draw is checked on.
You can see clearly how problematic not planar polygons are for the "springs" that try to hold the surface in shape. This creates the energy to let the head float and rotate or revolve, if you will.

Now have a look at the entire scene that you have sent. I used the "Iron" to get the structure "tamed". With some Initializing of the Cloth (Dresser), less tension release is noticeable. With this, the "auto rotation" is very low.

CV4_2023_drs_23_SIpn_21.c4d

Perhaps a mixture of Pins and the above is the winning mix to keep the Ironing low.

All the best

[MaverickMongoose]

Nice, I didnt know about the Iron tool, that did the trick! I guess it just didnt like the geometry.

I didnt think to use the dresser either, great idea!

Its working great now, thanks again Sassi!

And congrats for winning the Gold Remi btw;)

[Dr. Sassi]

You're very welcome, Maverick-Mongoose.

Thanks a lot for the lovely feedback about the Remi award; since ever I do anything with the people here on the forum in mind when I create. It evidently works to have a great audience :-), and be part of a great team!

I wanted to share one more option:

CV4_2023_drs_23_SIpn_31.c4d

Here I use a "cage" as a proxy/dummy object, which could be even more simplified. With this, any shoe inside the cage (or close to the surface) will stay as it is, how twisted you might go in the future with a model.

My best wishes