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Fixed in 2020.1.X

Fixed in 2019.4.X



Found in







Issue ID




Sphere's cloth explodes/rotates and constraints disappear (only one is left) when entering Play mode



How to reproduce:
1. Open the attached '' project
2. In the Hierarchy window select 'TwoSpheres' > 'InnerSphere No Scaling' > 'OuterSphere'
3. In the Inspector window select 'Edit Cloth Constraints' and observe the constraints in the Scene view
4. Enter Play mode and observe the sphere's behavior
5. Exit Play mode and observe the cloth's constraints

Expected result: Cloth does not explode and sags down on the inner sphere, the constraints stay unchanged
Actual result: Cloth explodes and rotates with the inner sphere, only one constraint is left

Reproducible with: 2017.4.36f1, 2018.4.16f1, 2019.2.20f1, 2019.3.0f6, 2020.1.0a21

In 2017.4.36f1 and 2019.2.20f1 cloth seems to explode and fly away from the sphere
In 2017.4.36f1 and 2018.4.16f1 cloth's constraints remain unchanged

  1. Resolution Note (fix version 2020.1):

    Fixed in 2020.2.0a21

  2. Resolution Note (fix version 2020.1):

    Fixed in 2020.1.3f1

  3. Resolution Note (fix version 2019.4):

    Fixed in 2019.4.9f1

Comments (5)

  1. SHoe

    Jun 15, 2020 20:39

    Are you guys able to make the cloth simulate in world space? I have it as a cape on a character in my 2.5d platformer, but the simulation is reversed when the character is rotated 180 degree.

  2. Qleenie

    Mar 19, 2020 19:26

    Maybe would be good to rename this ticket ? Seems surface penetration is not working correctly at all. as this is important part of cloth, this should also appear as known issues in the release notes.

  3. Qleenie

    Mar 04, 2020 10:08

    Is there any news about this? Any plans on fixing this issue?

  4. atomicjoe

    Feb 02, 2020 19:15

    As noted by SomeGuy22, the exploding cloth is related to the use of the "Surface Penetration" settings per vertex: if you disable "Surface Penetration" the cloth behaves correctly.
    Also, the vertices reappear in edit mode once you deselect and reselect the cloth object.

  5. atomicjoe

    Jan 30, 2020 18:07

    Note: I chose to use a sphere mesh to showcase the worst scenario.
    When I use other cloth meshes, the behavior is less apparent but still present (blowing up of the cloth, strange forces, vertices disappearing in the editor after play mode...)
    All my cloth meshes have this behavior with Unity's Cloth component.

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