Does anyone know if it's possible to lock the distance between two verts? Say you have a line with just two verts and you lock the distance between them, so that you can still move them in the XYZ space however they will never be able to be moved longer then the distance they started at when you locked them? Hope this…
Snap a bone between them to get the distance and move that (bones by default wont stretch), then just snap the verts to the bone after you're done figuring out the new position.