Cloth Simulation works very strange

Hello. I’m trying to make simple curtains. But, after several hours of trying, I am still at the very begining.
When i play animation or try to bake it, i see that cloth modifier does not afect mesh as it supposed to (Cloth_Sim_Problem01.jpg), or ruin geometry, like, i don’t know. a godzilla. (Cloth_im_Problem02.jpg)
I attach screenshots and *.blend file. You’re my only hope ©


cloth_sim_problem.blend (2.6 MB)

P.S. I used GPU (GTX 1060 6gb) and CPU (Xeon E5450) rendering but effect is the same.

Three issues:

  • Your mesh is not fine enough.
  • It is not a good idea to instantaneously set the final shape key. The sim likes smooth changes.
  • putting all vertices in a plane, including clothpins doesn’t give the curtain a ‘seed’ to start wrinkling, so it will delay doing that undesirably. I changed that only for the left side, so you can see the difference.

Fixed version:

cloth_sim_problem.blend (948.4 KB)

In addition maybe you want to use more clothpins to prevent the artifacts there.

Thanks for your help, but i actualy see no difference. Both curtains looks weird as they looked before. When i try to play animation and slightly move the key curtains looks like at my first picture. When i try to bake, they looks like at second picture.

Ehm, what do you mean by slightly moving the key?

Tried again on a different system. When playing animation on the file (as is) it works perfectly fine to me.

Like in this tutorial. https://www.youtube.com/watch?v=IKwXyPK8VbQ I start animation, then slightly, with my mouse pressed and hold, drag Key1:Value to slowly change value from 0 to 0.5 and further. For the first time it worked for me, but now it does not.

Why not keyframe it instead (as I did in my blend)? That way it is reproducible.

I look through your file once more. May be i lost something. But how i can keyframe an animation which never play properly.


It seems that blender or my pc is out of computing power. May be 8Gb DDRII is bottleneck.

Uh. No, that is not like it looks for me.

Can someone else please try it, too?

About memory, hmm, 8 GB is not plenty, but for such a simply example it should be more than sufficient. I did the testing and tweaking on my laptop, which also has only 8 GB.

Your fixed version looks excellent here in 2.80 beta.

I’m also running on a 6GB 1060 as the OP is. Nothing about this should care about your video card as far as I can think of. The simulation requires only 300MB or system memory for Blender and basically zero GPU resources.