Add reviewed MakeHuman head prototype (vision gate rejected)

tools/blender_assets.py

@@ -968,11 +968,12 @@ def _head_proto(mats, spec, subdiv=48):
 def _makehuman_head(mats, spec):
     """MakeHuman head shape plus the project's eye/mouth/brow pieces.
 
-    The AI-judged head rework (2026-11-04) picked the decimated MakeHuman head
-    over the displacement shell: it keeps the nose/chin/jaw landmarks at 1,573
-    tris. The MakeHuman mesh has no eyeballs, so the project's sclera/iris/lid/
-    brow pieces are added at the MakeHuman landmarks (eyes ≈ ±0.052, −0.160,
-    1.664) for readability. Blender Z-up, face front −Y.
+    The AI-judged head rework (2026-11-04) picked the MakeHuman head over the
+    displacement shell: it keeps the nose/chin/jaw landmarks. Newer part builds
+    carry their own embedded eye/iris/pupil/mouth geometry, so those materials
+    are preserved; the older shell-only asset still gets the project's
+    sclera/iris/lid/brow pieces added at the MakeHuman landmarks. Blender Z-up,
+    face front −Y.
     """
     skin, acc, hair = mats["skin"], mats["accessory"], mats["hair"]
     white = material("eye_white", textured_solid=True)
@@ -991,9 +992,24 @@ def _makehuman_head(mats, spec):
     if head is None:
         raise SystemExit(f"no head mesh in {src}")
     head.name = "HeadShell"
-    # The decimated MakeHuman "hair" scalp slot reads as shaggy shards; collapse
-    # the head to one skin slot so the join does not collide with the body's
-    # cloth/pants slots (the project `_hair` cap provides hair later).
+    # Newer MakeHuman part builds carry their own eye/mouth/brow materials and
+    # geometry. Use those instead of adding the project's primitive face pieces
+    # a second time; only the old shell-only asset falls through to that path.
+    embedded = {m.name.split(".")[0] for m in head.data.materials if m}
+    if "eye_white" in embedded:
+        # Preserve the embedded iris/pupil/mouth materials; only map the
+        # project contract slots onto the imported head.
+        remap = {"skin": skin, "eye_white": white, "hair": hair}
+        for index, mat in enumerate(list(head.data.materials)):
+            if mat:
+                target = remap.get(mat.name.split(".")[0])
+                if target is not None:
+                    head.data.materials[index] = target
+        return [head]
+
+    # The old decimated MakeHuman "hair" scalp slot reads as shaggy shards;
+    # collapse the head to one skin slot so the join does not collide with the
+    # body's cloth/pants slots (the project `_hair` cap provides hair later).
     head.data.materials.clear()
     head.data.materials.append(skin)
     # Clean the ragged neck cut left by the Head-group extraction: bisect below