NS-23: Direct step-down while on ns19_bump up to auth horiz limit

Nav paths often wrap along bump rims when the goal is far; the 8 m cap then
disabled step-off and left rim-following. Detect NS-19 bumps via
group on footprint rays; when any hit is a bump and vertical drop is in the
NS-19 band, steer straight to the goal up to 18 m (server max step). Non-bump
podiums keep the 8 m close cap. Single footprint pass returns max_y + bump.

client/scripts/player.gd

@@ -3,7 +3,7 @@ extends CharacterBody3D
 ## NS-23: Follow server move target on walkable geometry.
 ##
 ## Horizontal velocity toward nav waypoint or goal; `velocity.y` stays 0 except a short **step-off**
-## nudge (see `_nav_short_step_down_use_goal_direct`) so NS-19 bumps can drop without full gravity.
+## nudge (see `_use_direct_step_down_steering`) so NS-19 bumps can drop without full gravity.
 ## Move **legality** is server MoveCommand only — not reimplemented here.
 ##
 ## Nav for detours; short local step-down (feet vs goal Y, not body origin) may bypass waypoints.
@@ -17,7 +17,10 @@ const STEP_OFF_FLOOR_MARGIN: float = 0.04
 ## Only NS-19-sized step downs (not cliffs); allows a wider horiz cap without bee-lining big drops.
 const STEP_OFF_MIN_DROP: float = 0.055
 const STEP_OFF_MAX_DROP: float = 0.24
-const STEP_OFF_MAX_HORIZ: float = 8.0
+## Past this, only direct step-down when footprint still touches `ns19_bump` (nav rim paths).
+const STEP_OFF_CLOSE_HORIZ: float = 8.0
+## Match server `MovementValidation.MaxHorizontalStep` default; no bee-line past this.
+const STEP_OFF_MAX_HORIZ_AUTH: float = 18.0
 const FLOOR_PROBE_BODY_Y_OFFSET: float = -0.55
 ## Extra xz rays for step-off; max Y keeps bump support when center ray sees floor first.
 const STEP_FOOTPRINT_HALF: float = 0.2
@@ -55,13 +58,17 @@ func snap_to_server(world_pos: Vector3) -> void:
 	_nav_agent.set_target_position(world_pos)
 
 
-func _ray_floor_y_at(from: Vector3) -> float:
+func _ray_floor_hit(from: Vector3) -> Dictionary:
 	var space: PhysicsDirectSpaceState3D = get_world_3d().direct_space_state
 	var to: Vector3 = from + Vector3(0.0, -FLOOR_PROBE_DOWN, 0.0)
 	var q: PhysicsRayQueryParameters3D = PhysicsRayQueryParameters3D.create(from, to)
 	q.collision_mask = 1
 	q.exclude = [get_rid()]
-	var hit: Dictionary = space.intersect_ray(q)
+	return space.intersect_ray(q)
+
+
+func _ray_floor_y_at(from: Vector3) -> float:
+	var hit: Dictionary = _ray_floor_hit(from)
 	if hit.is_empty():
 		return from.y
 	var pv: Variant = hit.get("position")
@@ -70,6 +77,15 @@ func _ray_floor_y_at(from: Vector3) -> float:
 	return from.y
 
 
+func _collider_in_ns19_bump(collider: Variant) -> bool:
+	var n: Node = collider as Node
+	while n:
+		if n.is_in_group("ns19_bump"):
+			return true
+		n = n.get_parent()
+	return false
+
+
 func _floor_y_under_body() -> float:
 	var y_center: float = _ray_floor_y_at(global_position)
 	var lower: Vector3 = global_position + Vector3(0.0, FLOOR_PROBE_BODY_Y_OFFSET, 0.0)
@@ -77,9 +93,8 @@ func _floor_y_under_body() -> float:
 	return maxf(y_center, y_lower)
 
 
-## Max floor Y under capsule + xz offsets (step-off). Fights lip rays that hit ground too early.
+## One ray pass: max floor Y under footprint + whether any hit is an NS-19 bump (`ns19_bump` group).
-func _floor_y_max_under_capsule_footprint() -> float:
+func _footprint_step_down_state() -> Dictionary:
-	var best: float = _floor_y_under_body()
 	var p: Vector3 = global_position
 	var h: float = STEP_FOOTPRINT_HALF
 	var oxz: Array[Vector3] = [
@@ -92,11 +107,37 @@ func _floor_y_max_under_capsule_footprint() -> float:
 		Vector3(-h, 0.0, h),
 		Vector3(-h, 0.0, -h),
 	]
+	var best_y: float = 0.0
+	var got: bool = false
+	var on_bump: bool = false
+	for yoff: float in [0.0, FLOOR_PROBE_BODY_Y_OFFSET]:
+		var from_c: Vector3 = p + Vector3(0.0, yoff, 0.0)
+		var hit_c: Dictionary = _ray_floor_hit(from_c)
+		if not hit_c.is_empty():
+			var yc: float = (hit_c.get("position") as Vector3).y
+			if not got:
+				best_y = yc
+				got = true
+			else:
+				best_y = maxf(best_y, yc)
+			if not on_bump and _collider_in_ns19_bump(hit_c.get("collider")):
+				on_bump = true
 	for d: Vector3 in oxz:
-		best = maxf(best, _ray_floor_y_at(p + d))
+		for yoff2: float in [0.0, FLOOR_PROBE_BODY_Y_OFFSET]:
-		var lower_from: Vector3 = p + d + Vector3(0.0, FLOOR_PROBE_BODY_Y_OFFSET, 0.0)
+			var from_o: Vector3 = p + d + Vector3(0.0, yoff2, 0.0)
-		best = maxf(best, _ray_floor_y_at(lower_from))
+			var hit_o: Dictionary = _ray_floor_hit(from_o)
-	return best
+			if not hit_o.is_empty():
+				var yo: float = (hit_o.get("position") as Vector3).y
+				if not got:
+					best_y = yo
+					got = true
+				else:
+					best_y = maxf(best_y, yo)
+				if not on_bump and _collider_in_ns19_bump(hit_o.get("collider")):
+					on_bump = true
+	if not got:
+		best_y = _floor_y_under_body()
+	return {"max_y": best_y, "touches_ns19_bump": on_bump}
 
 
 ## Footing under goal xz (surface Y). Server goal.y may be capsule center (e.g. 0.9) or pick surface
@@ -111,8 +152,10 @@ func _destination_footing_y() -> float:
 	return y
 
 
-func _nav_short_step_down_use_goal_direct() -> bool:
+func _use_direct_step_down_steering() -> bool:
-	var floor_y: float = _floor_y_max_under_capsule_footprint()
+	var st: Dictionary = _footprint_step_down_state()
+	var floor_y: float = float(st["max_y"])
+	var on_bump: bool = bool(st["touches_ns19_bump"])
 	var dest_floor_y: float = _destination_footing_y()
 	if dest_floor_y >= floor_y - STEP_OFF_FLOOR_MARGIN:
 		return false
@@ -122,9 +165,11 @@ func _nav_short_step_down_use_goal_direct() -> bool:
 	var hd: float = Vector2(
 		_auth_walk_goal.x - global_position.x, _auth_walk_goal.z - global_position.z
 	).length()
-	if hd > STEP_OFF_MAX_HORIZ:
+	if hd > STEP_OFF_MAX_HORIZ_AUTH:
 		return false
-	return true
+	if on_bump:
+		return true
+	return hd <= STEP_OFF_CLOSE_HORIZ
 
 
 func _set_horizontal_velocity_toward(point: Vector3) -> void:
@@ -161,7 +206,7 @@ func _physics_process(_delta: float) -> void:
 		move_and_slide()
 		return
 
-	if _nav_short_step_down_use_goal_direct():
+	if _use_direct_step_down_steering():
 		_set_horizontal_velocity_toward(_auth_walk_goal)
 		velocity.y = -STEP_OFF_DESCEND_SPEED
 		move_and_slide()