What's the constraint between skeletal particles and bones? And can I disable it?

[josemendez]

When the "Skeleton Sampling" is enabling when generating particles from the softbody blueprint editor, the generated particles since to move along with the bones. My questions are:

1. What's the constraint taking place here? Distance? Pin? Shape matching?

No constraints are used, since there’s no physics involved. Bone particles are simply fixed (their inverse mass set to zero) and then their position is updated every frame to match the corresponding bone. Kinda like what static attachments do, but without the hassle of setting up the attachments yourself.

Other particles around them follow the bone particles because they’re linked via shape matching constraints.

2. Can I disable it? In other words, I'd like the particles to be generated at the positions of the bones, but I'd like them to work just like volume particles and surface particles: bound to other particles by shape matching constraints, but not bound to the bone.

There’s no way to disable this, but there’s no technical limitation that prevents it either. It’s just that sampling the bone hierarchy with particles and then have the particles ignore the bones didn’t seem to have any use that would justify a “disable” option: you just don’t provide a skeleton when creating the blueprint.

Could you describe your use case for this?