some meshes in the first skin are parented with the second skin
This is the wrong terminology. My guess is you are trying to say: some meshes in the skin you want to keep are linked meshes, and the source mesh is in the skin you want to delete. If you delete that skin, the source meshes are deleted, which in turn cause the linked meshes to also be deleted.
In 3.7 you can unlink a mesh using the button on the right, here:
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After unlinking your linked meshes, the skin containing the source meshes can be deleted without also deleting the meshes you want to keep.
If you can't use 3.7, then if you move a linked mesh to another slot (doesn't need to be another skeleton), the source mesh and any other linked meshes are also moved. Here's an example from the goblins
project:
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That is a linked mesh in the goblingirl
skin. The source mesh is in the same placeholder, but in the goblin
skin. If I delete the goblin
skin, I'll lose the goblingirl
mesh.
Drag the linked mesh to a bone and create a new slot (I named it temp
, but the name does not matter):
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The source mesh was also moved.
Next move the linked mesh back to the skin placeholder, where you want it:
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The source mesh is also moved to the same slot. Lastly, delete the temp
slot. Now you can delete the goblin
skin without losing the mesh. You will need to keep the source mesh.