fix: empty 3x3 tiles below candy cannon and add outline shaders to cannon, projectiles, bubbles and vfx

scripts/controllers/candy_cannon_controller.gd

@@ -9,7 +9,38 @@ class_name CandyCannonController
 @onready var tank = $Tank if has_node("Tank") else null
 
 func _ready() -> void:
-	pass
+	_apply_outline_recursive(self)
+
+func _apply_outline_recursive(node: Node) -> void:
+	if node is MeshInstance3D and node.mesh:
+		# Some procedural meshes might not have get_surface_count or it might be 1.
+		# If the mesh has material_override, apply outline to that
+		if node.material_override and node.material_override is StandardMaterial3D:
+			var mat = node.material_override
+			if not mat.next_pass:
+				var outline_mat = ShaderMaterial.new()
+				outline_mat.shader = load("res://assets/shaders/outline3d.gdshader")
+				mat.next_pass = outline_mat
+		else:
+			for i in range(node.mesh.get_surface_count()):
+				var mat = node.get_active_material(i)
+				if mat:
+					if not mat.next_pass:
+						var unique_mat = mat.duplicate()
+						var outline_mat = ShaderMaterial.new()
+						outline_mat.shader = load("res://assets/shaders/outline3d.gdshader")
+						unique_mat.next_pass = outline_mat
+						node.set_surface_override_material(i, unique_mat)
+	
+	if node is GPUParticles3D and node.draw_pass_1 and node.draw_pass_1.material:
+		var mat = node.draw_pass_1.material
+		if not mat.next_pass:
+			var outline_mat = ShaderMaterial.new()
+			outline_mat.shader = load("res://assets/shaders/outline3d.gdshader")
+			mat.next_pass = outline_mat
+			
+	for child in node.get_children():
+		_apply_outline_recursive(child)
 
 func _process(delta: float) -> void:
 	if ring1: ring1.rotate_y(delta * 1.5)
@@ -42,7 +73,8 @@ func spawn_projectile(target_world_pos: Vector3, duration: float) -> void:
 	mat.emission_energy_multiplier = 3.0
 	projectile.material_override = mat
 	
-	get_tree().get_root().add_child(projectile)
+	projectile.top_level = true
+	add_child(projectile)
 	
 	# Start projectile slightly above the cannon center
 	projectile.global_position = global_position + Vector3(0, 3.0, 0)
@@ -75,6 +107,7 @@ func spawn_projectile(target_world_pos: Vector3, duration: float) -> void:
 	particles.amount = 16
 	particles.lifetime = 0.4
 	projectile.add_child(particles)
+	_apply_outline_recursive(projectile)
 		
 	tween.set_parallel(true)
 	tween.tween_property(projectile, "global_position:x", target_world_pos.x, duration).set_trans(Tween.TRANS_LINEAR)

scripts/managers/gauntlet_manager.gd

@@ -412,11 +412,11 @@ func _apply_arena_setup() -> void:
 			var pos = Vector2i(x, z)
 			
 			# Center 3x3 block: NPC obstacle (Candy Pump)
-			if _is_npc_zone(pos):
-				# Make the floor walkable visually instead of obstacle red
-				gridmap.set_cell_item(Vector3i(x, 0, z), TILE_WALKABLE)
-				gridmap.set_cell_item(Vector3i(x, 1, z), -1)
-				continue
+				if _is_npc_zone(pos):
+					# Make the floor empty (-1) beneath the Candy Pump
+					gridmap.set_cell_item(Vector3i(x, 0, z), -1)
+					gridmap.set_cell_item(Vector3i(x, 1, z), -1)
+					continue
 			
 			# Boundary walls: perimeter (row 0, row 19, col 0, col 19)
 			if x == 0 or x == ARENA_COLUMNS - 1 or z == 0 or z == ARENA_ROWS - 1:
@@ -982,6 +982,12 @@ func _spawn_impact_particles(targets: Array) -> void:
 		spatial_mat.emission_enabled = true
 		spatial_mat.emission = Color(1.0, 0.6, 0.8)
 		spatial_mat.emission_energy_multiplier = 2.0
+		
+		# Outline shader for splash VFX
+		var outline_mat = ShaderMaterial.new()
+		outline_mat.shader = load("res://assets/shaders/outline3d.gdshader")
+		spatial_mat.next_pass = outline_mat
+		
 		mesh.material = spatial_mat
 		particles.draw_pass_1 = mesh
 
@@ -1558,6 +1564,11 @@ func _spawn_bubble_visual(center: Vector2i) -> void:
 	mat.emission_enabled = true
 	mat.emission = Color(1.0, 0.2, 0.6)
 	mat.emission_energy_multiplier = 1.5
+	
+	var outline_mat = ShaderMaterial.new()
+	outline_mat.shader = load("res://assets/shaders/outline3d.gdshader")
+	mat.next_pass = outline_mat
+	
 	mesh_inst.material_override = mat
 
 	var main = get_node_or_null("/root/Main")