A null body part is simply a body part that has no corresponding geometry inthe OBJ. I don't know what tuts there are out there, but Bloodsong's Painlessly Easy Conforming Clothing tutorial hits on the topic in a roundabout way, because the techniques he describes don't require you to remove body parts from the base conformer. Basically: You run the hip all the way down the centre. You tun the thighs all the way down the sides and they are parented by the hip. You give the thighs and hip morph targets, something like 'Left Shin Bend', that are the objects at a 90 degree bend (don't try to push for more because a morph makes a vertex go straight to it's target, not in a curve). You put shins in the CR2, but they do not refer to any geometry in the OBJ file. But since they are there, when it comforms they will adopt the pose of their conforming target. You add ERC to slave the morph dials to the shin position, with a deltaAddDelta of 1/90th or -1/90th (can't recall which way the shin bend goes), so that when the lShin is at a 90-degree angle the MT is at 1. This may still cause some breakage along the way, so some manual MTs to spread the skirt and fix things would be good. This will still not work perfectly at >90 bend of the shins, so be sure to not hide the MTs so the user can tweak the dials manually to get the higher bends to look right.