Add the fused hand prototype (hand_l_proto/hand_r_proto) and record the finger-articulation decision

tools/blender_assets.py

@@ -1007,6 +1007,32 @@ def _hands_and_shoes(mats, spec):
     return parts
 
 
+def _hand_proto(mats, spec, side=-1.0):
+    """Connected hand: palm, four fingers and a thumb fused into one mesh.
+
+    The shipped hand is separate primitive parts that read as a mitten at
+    conversation distance; fusing the finger bases into the palm gives a
+    connected hand with readable finger separation. `side` is −1 (left, x<0)
+    or +1 (right, x>0).
+    """
+    hs = _hands_and_shoes(mats, spec)
+
+    def _cx(o):
+        xs = [v.co.x for v in o.data.vertices]
+        return (min(xs) + max(xs)) / 2
+
+    hand = [o for o in hs
+            if o.name.startswith(("Palm", "Finger", "Fingertip", "Thumb", "ThumbTip"))
+            and (_cx(o) < 0 if side < 0 else _cx(o) > 0)]
+    obj = join(hand, "HandL" if side < 0 else "HandR")
+    bm = bmesh.new()
+    bm.from_mesh(obj.data)
+    bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=0.006)
+    bm.to_mesh(obj.data)
+    bm.free()
+    return obj
+
+
 def _clothing(spec, mats):
     layer = spec["layer"]
     cloth = mats["cloth"]