avoid stones when chasing

scripts/Enemy.gd

@@ -94,12 +94,31 @@ func _chase(delta: float) -> void:
 			target.take_damage(damage_to_player)
 	if dist > 0.05:
 		var dir := diff.normalized()
+		dir = _avoid_rocks(dir)
 		velocity.x = dir.x * move_speed
 		velocity.z = dir.z * move_speed
 		rotation.y = lerp_angle(rotation.y, atan2(dir.x, dir.z), 8.0 * delta)
 	velocity.y = 0.0
 	move_and_slide()
 
+const AVOID_RADIUS   := 1.6
+const AVOID_STRENGTH := 2.2
+
+func _avoid_rocks(desired: Vector3) -> Vector3:
+	var push := Vector3.ZERO
+	for rock in get_tree().get_nodes_in_group("rocks"):
+		if not is_instance_valid(rock):
+			continue
+		var away := global_position - (rock as Node3D).global_position
+		away.y = 0.0
+		var d := away.length()
+		if d < AVOID_RADIUS and d > 0.01:
+			push += away.normalized() * (1.0 - d / AVOID_RADIUS)
+	if push.length() < 0.01:
+		return desired
+	var steered := desired + push * AVOID_STRENGTH
+	return steered.normalized() if steered.length() > 0.01 else desired
+
 func _fly(delta: float) -> void:
 	var speed_now := Vector2(fly_vel.x, fly_vel.z).length()
 	velocity = fly_vel