fix(parity): implement ground click ripple, target select glow, and 3D projectile obstacle collision with regression probes

project/fly_object.gd

@@ -196,12 +196,25 @@ class FlyInstance extends RefCounted:
 				_explode()
 				return false
 
-		if data.hit_on_background and _world and _world.has_method("sample_height"):
-			var gh := float(_world.call("sample_height", pos.x, pos.z))
-			if gh > pos.y:
-				_emit("at_background")
-				_explode()
-				return false
+		if data.hit_on_background:
+			if _world and _world.has_method("sample_height"):
+				var gh := float(_world.call("sample_height", pos.x, pos.z))
+				if gh > pos.y:
+					_emit("at_background")
+					_explode()
+					return false
+			# 40250 CFlyingInstance::Update FCheckBackgroundDuringFlying:
+			# 空间 3D 建筑与静态障碍物碰撞（碰撞层 2: StaticBody3D）
+			if _world is Node3D and _world.is_inside_tree():
+				var w3d: World3D = _world.get_world_3d()
+				if w3d and w3d.direct_space_state:
+					var q := PhysicsRayQueryParameters3D.create(last_pos, pos, 2)
+					var hit := w3d.direct_space_state.intersect_ray(q)
+					if not hit.is_empty():
+						pos = hit.position
+						_emit("at_background")
+						_explode()
+						return false
 		return true
 
 	func _explode(bomb := true) -> void: