CDO Thank you for the detailed explanation. I agree that being able to weld multiple meshes at once would be useful, so I created an enhancement issue on GitHub for it: EsotericSoftware/spine-editor1017
By the way, I believe the impression that this used to work may be a misunderstanding. I went back and tested older versions, including 4.2 and early 4.3-beta builds. In 4.2, the Weld button becomes disabled entirely when multiple meshes are selected. Starting from a certain point during the 4.3-beta cycle, the Weld button could still be pressed even with multiple meshes selected, but the weld operation itself was only applied to the first selected mesh. Simultaneous welding of multiple meshes was still not possible.
Regarding your second point, the request to be able to unlink weights partway through can actually be achieved using linked meshes. However, linked meshes are somewhat less flexible than Weld in the sense that you cannot convert an already existing mesh attachment into a linked mesh afterward. In addition, while Weld can work between meshes with different vertex counts or shapes, linked meshes require exactly the same vertex count, mesh shape, and bind bone list.
At the same time, I think that is exactly what makes automatic Weld behavior complicated. With the kind of dynamic Weld behavior you described, there could be cases where a mesh is continuously referencing part of another mesh’s weights, but later the bound bones are changed and the two meshes no longer share the same bone setup at all. Similarly, when bindings are updated in Animate mode, there may be situations where users want the weights to update as vertex positions change, and other situations where they do not. It feels like handling all of those edge cases properly would require fairly complex logic. That is why I think it would be difficult for Weld to behave automatically in that way.
Please feel free to share any additional thoughts or feedback you may have.
