characters/skin_joint_helper.gd

@@ -108,6 +108,19 @@ static func _dist_to_chain(p: Vector3, chain: PackedVector3Array) -> float:
 
 
 ## Drive the helpers. MUST run inside the skeleton's modification pass.
+##
+## Two things happen per joint:
+##
+##   ROTATION — the helper takes half the child's bend, so no vertex ever blends
+##   across the full angle.
+##
+## Scaling the helper to widen the joint back out was tried and removed. The
+## geometry is right — a blend across θ thins by cos(θ/2), which is |q.w| — but a
+## BONE scale is far too blunt an instrument for it: it fattens every vertex on
+## the helper regardless of whether that vertex was collapsing, which ballooned
+## parts of the thigh to 167% while the worst-collapsing vertices (which are not
+## on the helper at all) did not move off 0.83. Per-vertex correction is what
+## that idea needs, and a bone cannot express it.
 static func update(skeleton: Skeleton3D, driven: Array) -> void:
 	for d in driven:
 		skeleton.set_bone_pose_rotation(d[1],