Try out simple portals for hermione level

addons/simple-portal-system/scripts/portal.gd

@@ -117,7 +117,7 @@ func _create_viewport() -> void:
 	_viewport = SubViewport.new()
 	_viewport.name = "Viewport"
 	_viewport.render_target_clear_mode = SubViewport.CLEAR_MODE_ONCE
-	add_child(_viewport)
+	exit_portal.add_child(_viewport)
 	material_override.set_shader_parameter("albedo", _viewport.get_texture())
 
 	# Create the exit camera which renders the portal surface for the viewport

levels/level_hermione.tscn

@@ -1,10 +1,26 @@
-[gd_scene load_steps=6 format=3 uid="uid://dgvdetmbv5jya"]
+[gd_scene load_steps=9 format=4 uid="uid://dgvdetmbv5jya"]
 
 [ext_resource type="PackedScene" uid="uid://b5x7fmpwck335" path="res://hud.tscn" id="1_2k7q4"]
 [ext_resource type="Script" uid="uid://ca45js46kc0l7" path="res://levels/level_hermione.gd" id="1_gyvwl"]
 [ext_resource type="PackedScene" uid="uid://drhaqr78kv1o2" path="res://levels/room_hermione_outside.tscn" id="2_empe6"]
 [ext_resource type="PackedScene" uid="uid://ci81nttn6foio" path="res://levels/room_hermione_inside.tscn" id="2_lv1mc"]
 [ext_resource type="PackedScene" uid="uid://cgdlowfuuorvi" path="res://player.tscn" id="3_gyvwl"]
+[ext_resource type="PackedScene" uid="uid://jecigkibqyew" path="res://portal.tscn" id="6_owlrt"]
+[ext_resource type="PackedScene" uid="uid://d1dtxvwk86ple" path="res://procedural_mesh_maker.tscn" id="7_ucmro"]
+
+[sub_resource type="ArrayMesh" id="ArrayMesh_owlrt"]
+_surfaces = [{
+"aabb": AABB(-0.45, -1.075, 0, 0.9, 2.15, 1e-05),
+"attribute_data": PackedByteArray("AAAAAAAAAAAAAIA/AAAAAAAAAAAAAIA/AACAPwAAgD8AAAAAAAAAAAAAgD8AAAAAAAAAAAAAgD8AAIA/AACAPw=="),
+"format": 34359742487,
+"index_count": 30,
+"index_data": PackedByteArray("AAABAAQABAABAAUAAQADAAUABQADAAcAAwACAAcABwACAAYAAgAAAAYABgAAAAQABAAFAAYABgAFAAcA"),
+"name": "Portal Material",
+"primitive": 3,
+"uv_scale": Vector4(0, 0, 0, 0),
+"vertex_count": 8,
+"vertex_data": PackedByteArray("ZmbmvpqZiT8AAAAAZmbmPpqZiT8AAAAAZmbmvpqZib8AAAAAZmbmPpqZib8AAAAAZmbmvpqZiT8AAAAAZmbmPpqZiT8AAAAAZmbmvpqZib8AAAAAZmbmPpqZib8AAAAA/3//f/9/AID/f/9//38AgP9//3//fwCA/3//f/9/AID/f/9//38AgP9//3//fwCA/3//f/9/AID/f/9//38AgA==")
+}]
 
 [node name="level_hermione" type="Node"]
 script = ExtResource("1_gyvwl")
@@ -30,6 +46,11 @@ render_target_update_mode = 4
 unique_name_in_owner = true
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 6.08041, 1.41104, 0)
 
+[node name="PortalOutside" parent="SubViewportContainer/OutsideWorld/OutsideWorldContainer" node_paths=PackedStringArray("main_camera") instance=ExtResource("6_owlrt")]
+transform = Transform3D(-4.37114e-08, 0, 1, 0, 1, 0, -1, 0, -4.37114e-08, 3.505, 1.55, 0.5)
+mesh = SubResource("ArrayMesh_owlrt")
+main_camera = NodePath("../Player/Camera3D")
+
 [node name="HUD" parent="." instance=ExtResource("1_2k7q4")]
 
 [node name="TeleportButton" type="Button" parent="HUD"]
@@ -45,4 +66,18 @@ size = Vector2i(1920, 1080)
 
 [node name="room_hermione_inside" parent="InsideWorld/InsideWorldContainer" instance=ExtResource("2_lv1mc")]
 
+[node name="PortalInside" parent="InsideWorld/InsideWorldContainer" node_paths=PackedStringArray("main_camera", "exit_portal") instance=ExtResource("6_owlrt")]
+transform = Transform3D(1.19249e-08, 0, -1, 0, 1, 0, 1, 0, 1.19249e-08, 3.505, 1.55, 0.5)
+mesh = SubResource("ArrayMesh_owlrt")
+main_camera = NodePath("../../../SubViewportContainer/OutsideWorld/OutsideWorldContainer/Player/Camera3D")
+exit_portal = NodePath("../../../SubViewportContainer/OutsideWorld/OutsideWorldContainer/PortalOutside")
+
+[node name="ProceduralMeshMaker" parent="." node_paths=PackedStringArray("portal") instance=ExtResource("7_ucmro")]
+portal = NodePath("../InsideWorld/InsideWorldContainer/PortalInside")
+height = 2.15
+width = 0.9
+indent = 0.0
+
 [connection signal="pressed" from="HUD/TeleportButton" to="." method="_on_teleport_button_pressed"]
+
+[editable path="SubViewportContainer/OutsideWorld/OutsideWorldContainer/Player"]

portal.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://jecigkibqyew"]
+
+[ext_resource type="Script" uid="uid://d2bvvjsibau8c" path="res://addons/simple-portal-system/scripts/portal.gd" id="1_0r486"]
+
+[node name="Portal" type="MeshInstance3D"]
+script = ExtResource("1_0r486")