feat: thinner cel outline + procedural model actually holds its weapon

Outline: the inverted-hull width was tuned when the look was heavier and
now reads as a thick marker stroke. Cut every call site to roughly a third
(characters 0.012 -> 0.004, level geometry 0.015 -> 0.005, Neon Alley's
size-scaled clamp 0.02..0.05 -> 0.007..0.018) plus the shader default, so
the ink line stays readable without fattening every silhouette.

Third-person weapon on HumanoidModel: the gun was parented to root_pivot at
a fixed (-0.15, 1.0, 0.4) — floating 40 cm off the chest while both arms
posed at it from a distance. Give the rig a real right-hand node at the end
of the forearm and hang the weapon there, so it travels with the arm. Its
aim is re-derived from the body each frame (hand_r_pivot's global basis is
copied from root_pivot), otherwise the barrel would swing around with the
arm animation. The hold pose is retuned to match: right elbow tucked at the
ribs with a level forearm, left arm crossing to the handguard.

_seat_weapon_in_hand() slides each weapon along its own barrel axis so a
plausible grip lands in the fist regardless of where the artist left the
model origin. It measures with MeshInstance3D.get_aabb(), not
mesh.get_aabb() — the FBX gun parts are skinned, so the Mesh resource still
carries bind-pose bounds tens of metres across.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

characters/humanoid_model.gd

@@ -19,6 +19,7 @@ var upper_arm_r_pivot: Node3D
 var upper_arm_r: MeshInstance3D
 var lower_arm_r_pivot: Node3D
 var lower_arm_r: MeshInstance3D
+var hand_r_pivot: Node3D
 
 var thigh_l_pivot: Node3D
 var thigh_l: MeshInstance3D
@@ -116,7 +117,14 @@ func _ready() -> void:
 	lower_arm_r.position = Vector3(0, -0.175, 0)
 	lower_arm_r.cast_shadow = shadow_setting
 	lower_arm_r_pivot.add_child(lower_arm_r)
-	
+
+	# Right hand: the wrist joint at the far end of the forearm. The
+	# third-person weapon hangs here so it travels with the arm instead of
+	# floating in front of the chest.
+	hand_r_pivot = Node3D.new()
+	hand_r_pivot.position = Vector3(0, -0.35, 0)
+	lower_arm_r_pivot.add_child(hand_r_pivot)
+
 	# Legs (Thigh: 0.45 length, Calf: 0.45 length)
 	var t_leg_mesh = BoxMesh.new()
 	t_leg_mesh.size = Vector3(0.15, 0.45, 0.15)
@@ -166,7 +174,7 @@ func _ready() -> void:
 	# Cel-shade + ink outline the blocky fallback body so it matches skinned
 	# player models (shadows-only bodies skip it: outlines would cast shadows)
 	if not shadows_only:
-		LevelMaterials.apply_toon_recursive(root_pivot, 0.012)
+		LevelMaterials.apply_toon_recursive(root_pivot, 0.004)
 
 ## Skin System
 var current_skin: PlayerSkin
@@ -229,7 +237,7 @@ func _apply_color(col: Color) -> void:
 		head.mesh.material = hmat
 	# Re-toon after the material swap (fresh StandardMaterials above)
 	if not shadows_only:
-		LevelMaterials.apply_toon_recursive(root_pivot, 0.012)
+		LevelMaterials.apply_toon_recursive(root_pivot, 0.004)
 
 func update_state(state: String, speed: float, is_crouching: bool = false) -> void:
 	current_state = state
@@ -240,11 +248,14 @@ func update_state(state: String, speed: float, is_crouching: bool = false) -> vo
 var is_holding_weapon: bool = false
 
 func set_weapon(script_path: String) -> void:
-	# Clear existing weapons from root_pivot
-	for child in root_pivot.get_children():
-		if child.has_meta("is_third_person_weapon"):
-			child.queue_free()
-			
+	# Clear existing weapons (older builds parented them to root_pivot)
+	for parent in [root_pivot, hand_r_pivot]:
+		if not parent:
+			continue
+		for child in parent.get_children():
+			if child.has_meta("is_third_person_weapon"):
+				child.queue_free()
+
 	if script_path == "":
 		is_holding_weapon = false
 		return
@@ -269,13 +280,40 @@ func set_weapon(script_path: String) -> void:
 			# Toon shading only — FBX weapon normals tear inverted-hull outlines
 			LevelMaterials.apply_toon_recursive(w, 0.0)
 
-		# Force position after the weapon's _build_model() sets it for 1st person
-		w.position = Vector3(-0.15, 1.0, 0.4)
-		w.rotation_degrees = Vector3(0, 180, 0)
+		# Undo the first-person viewmodel placement from _build_model()
+		_seat_weapon_in_hand(w)
 	)
-		
-	# Attach to root_pivot so it stays steady and points perfectly forward
-	root_pivot.add_child(w)
+
+	# Riding the hand keeps the gun with the arm; _process re-aims it forward.
+	(hand_r_pivot if hand_r_pivot else root_pivot).add_child(w)
+
+
+## Slide the weapon along its own barrel axis so a plausible grip point — not
+## whatever origin the artist left the model at — ends up in the fist, and turn
+## it to face the way the body faces (the model is yawed 180° in _ready, so the
+## gun's -Z muzzle axis has to point along the model's local +Z).
+func _seat_weapon_in_hand(w: Node3D) -> void:
+	w.rotation_degrees = Vector3(0, 180, 0)
+	w.position = Vector3.ZERO
+	var min_t := INF   # most negative along the barrel = stock end
+	var max_t := -INF  # most positive = muzzle end
+	for mi in w.find_children("*", "MeshInstance3D", true, false):
+		if not mi.mesh:
+			continue
+		# mi.get_aabb(), NOT mi.mesh.get_aabb(): the FBX gun parts are skinned and
+		# the Mesh resource still carries huge bind-pose bounds.
+		var xf: Transform3D = w.global_transform.affine_inverse() * mi.global_transform
+		var aabb: AABB = mi.get_aabb()
+		for i in 8:
+			var t: float = (xf * aabb.get_endpoint(i)).dot(Vector3(0, 0, -1))
+			min_t = minf(min_t, t)
+			max_t = maxf(max_t, t)
+	if min_t > max_t:
+		return
+	# ~a third back from the muzzle is where a pistol grip sits on every gun in
+	# the set, which leaves real length of weapon behind the hand.
+	var grip_at := min_t + (max_t - min_t) * 0.32
+	w.position = Vector3(0, 0, -grip_at)
 
 func _set_shadows_recursive(node: Node) -> void:
 	if node is GeometryInstance3D:
@@ -438,15 +476,18 @@ func _process(delta: float) -> void:
 			
 	# Override right arm (and left) if holding a weapon
 	if is_holding_weapon and current_state != "death":
-		# Pose the right arm to look like it's holding the weapon handle
-		t_upper_arm_r_rot.x = -0.6
-		t_upper_arm_r_rot.z = 0.15
-		t_lower_arm_r_rot.x = -1.0
-		
-		# Pose the left arm to look like it's holding the foregrip
-		t_upper_arm_l_rot.x = -0.5
-		t_upper_arm_l_rot.z = -0.15
-		t_lower_arm_l_rot.x = -1.1
+		# Right arm holds the grip: elbow tucked at the ribs, forearm level so
+		# the fist (and the weapon parented to it) sits chest-high just in
+		# front of the torso rather than out at arm's length.
+		t_upper_arm_r_rot.x = -0.15
+		t_upper_arm_r_rot.z = -0.10
+		t_lower_arm_r_rot.x = -1.45
+
+		# Left arm crosses over to the handguard: up, in, and a little further
+		# forward than the grip hand.
+		t_upper_arm_l_rot.x = -0.55
+		t_upper_arm_l_rot.z = 0.55
+		t_lower_arm_l_rot.x = -1.0
 	
 	var lerp_speed = 40.0 * delta
 	root_pivot.position = root_pivot.position.lerp(t_root_pos, lerp_speed)
@@ -462,6 +503,12 @@ func _process(delta: float) -> void:
 	calf_l_pivot.rotation = _lerp_vec3(calf_l_pivot.rotation, t_calf_l_rot, lerp_speed)
 	calf_r_pivot.rotation = _lerp_vec3(calf_r_pivot.rotation, t_calf_r_rot, lerp_speed)
 
+	# The weapon rides the hand for position, but its AIM belongs to the body:
+	# cancel the arm chain's rotation so the barrel stays pointed where the
+	# player faces instead of swinging around with the arm animation.
+	if hand_r_pivot:
+		hand_r_pivot.global_basis = root_pivot.global_basis
+
 func _lerp_vec3(a: Vector3, b: Vector3, t: float) -> Vector3:
 	return Vector3(
 		lerp_angle(a.x, b.x, t),