Trouble with simulation shirt in 2.91

Hello. Trouble om the pictures… model have not penetration.
How I could fix it?

hey there!

first question - have your tried using the presets for things like, cotton, silk, etc?

Next - I was having similar issues with a different sort of setup, but what helped me was a few things - primarily, was make sure there was no penetration with the collision mesh to begin with. Like not even one vert. And btw this is includes the space with the collision thickness. It causes “pops” in the simulation and that will create a physics ripple through the whole mesh often blowing it out of whack.

Something else to pay attention to is your dampening and self collision. you might need to push those values up. Along with that is the mass.

Last thing I can suggest at first, is to make sure your object scale is something that makes sense in the real world. Physics in general is designed around real-world values. So if your character base mesh is very small, you will likely have issues with all default values.

First, turn on Self Collision for the cloth. I see that it is not checked in the image above.

General things for misbehaving cloth and sometimes other physics/hair:

  • Cloth behaves differently at different quality settings. You may have to increase the various quality or “steps” settings to get good results. Patience for the long simulation time is needed then.
  • Objects with physics should be life size or larger.
  • Sometimes models must be larger than life size. This helps when the cloth “hovers” too far from a character as if the character had a thin force field around it and small values in the various collision distances cause trouble. Watch for slow movement due to larger size though.
  • Set the distance values for collisions to small values like the 1mm you used above.
  • The collsion physics for your character also has distance values. Make Thickness Outer the same as the cloth distances for object and check Single Sided. Override Normals sometimes helps too.
  • Clipping distance for workspace view (on N panel): Set clip start and end to enclose the space of your scene and not much more. This allows bits/digits to be used for precision instead of large numbers. (This also fixed the rough hair problem here.)
  • A little Impluse Clamping can help when fast or sudden movements of the character cause cloth trouble.
  • Fast movements can cause trouble.