>>8987263You want to do the opposite: make some joints+the shape you need to cut from the figure to fit the joint and it's range of movement, save the joint+boolean together as one multi-body stl, and import THAT into the Blender/Zbrush/Meshmixer file. Position and resize as needed, then use the shape of the cut to make a boolean subtraction. Boom, articulation.
For the SLA printing, you can go with a Durable pp-like resin for everything, or you can start with that and mix in a super soft resin (ie 80A) until it has a consistency like softish vinyl and use that for everything but the joints themselves.
