My problem is that when connecting the bones with the mesh, one of the fins gets deformed. The other three fins move well, they don’t deform, but the first one (the one you see in the image) deforms. I thought it was an influence problem, but the mesh is completely red.
Does anyone know how to connect a bone to a mesh and that when I move the bone, the mesh does not deform, but does rotate?
Quick 'n dirty solution (without deleting vertex groups and no deforming of bone for other objects):
1.- Select the object and then select the armature.
2.- In Pose Mode, select the bone and with Ctrl+P >Set Parent To Bone.
3.- Uncheck Deform in the bone properties panel.