Update portal plugin to 1.0.1

Includes the flickering fix!

addons/portals/CHANGELOG.md

@@ -0,0 +1,13 @@
+### 1.0.1
+
+- Fix flickering when going sideways through a portal. PR #4
+
+# 1.0.0
+
+First public release! This plugin was developed as part of my master's thesis. As such, the thesis 
+itself is the best documentation at the moment:
+[https://is.muni.cz/th/ydltb](https://is.muni.cz/th/ydltb/?lang=en). 
+
+Also check out the included README.md for tips and potentially also the 
+[GitHub repository](https://github.com/VojtaStruhar/godot-portals-plugin)
+for some showcase levels.

addons/portals/plugin.cfg

@@ -3,5 +3,5 @@
 name="Portals 3D"
 description="Seamless portals plugin in 3D"
 author="Vojtech Struhar"
-version="1.0"
+version="1.0.1"
 script="plugin.gd"

addons/portals/scripts/portal_3d.gd

@@ -344,6 +344,9 @@ var portal_viewport: SubViewport = null
 class TeleportableMeta:
 	## Forward distance from the portal
 	var forward: float = 0
+	## True only if the [member Portal3D.player_camera] is a child of the object being teleported.
+	## In that case, we consider it the player.
+	var is_player: bool = false
 	## Meshes that the object gave for duplication. Retrieved by the 
 	## [constant Portal3D.DUPLICATE_MESHES_CALLBACK] callback.
 	var meshes: Array[MeshInstance3D] = []
@@ -468,7 +471,7 @@ func _ready() -> void:
 		teleport_area.collision_mask = teleport_collision_mask
 
 
-func _process(delta: float) -> void:
+func _process(_delta: float) -> void:
 	if Engine.is_editor_hint():
 		return
 	
@@ -552,14 +555,13 @@ func _process_teleports() -> void:
 			on_teleport.emit(teleportable)
 			exit_portal.on_teleport_receive.emit(teleportable)
 			
-			# Force the cameras to refresh if we just teleported a player
+			
-			var was_player := not str(teleportable.get_path_to(player_camera)).begins_with(".")
+			if tp_meta.is_player:
-			if was_player:
 				_process_cameras()
 				exit_portal._process_cameras()
 			
 			# Resolve teleport interactions
-			if was_player and _check_tp_interaction(TeleportInteractions.PLAYER_UPRIGHT):
+			if tp_meta.is_player and _check_tp_interaction(TeleportInteractions.PLAYER_UPRIGHT):
 				get_tree().create_tween().tween_property(teleportable, "rotation:x", 0, 0.3)
 				get_tree().create_tween().tween_property(teleportable, "rotation:z", 0, 0.3)
 			
@@ -691,11 +693,22 @@ func _on_window_resize() -> void:
 #region UTILS
 
 func _construct_tp_metadata(node: Node3D) -> void:
+	var teleportable = node.get_node(node.get_meta(TELEPORT_ROOT_META, ".")) # Usually the node itself
+	
 	var meta = TeleportableMeta.new()
 	meta.forward = forward_distance(node)
+	meta.is_player = not str(teleportable.get_path_to(player_camera)).begins_with(".")
 	
-	if _check_tp_interaction(TeleportInteractions.DUPLICATE_MESHES) and \
+	## This is a workaround to prevent flickering when traversing portals.
-		node.has_method(DUPLICATE_MESHES_CALLBACK):
+	## There is a bit of lag when restarting RTT when the exit portal becomes physically visible.
+	## Ensuring both portals are updated regardless of visibility while in the portals prevents flickering.
+	## More info: https://github.com/VojtaStruhar/godot-portals-plugin/pull/4
+	if meta.is_player:
+		_set_portal_pair_update_mode(SubViewport.UPDATE_ALWAYS)
+	
+	if _check_tp_interaction(TeleportInteractions.DUPLICATE_MESHES)\
+			and node.has_method(DUPLICATE_MESHES_CALLBACK):
+		
 		meta.meshes = node.call(DUPLICATE_MESHES_CALLBACK)
 		for m: MeshInstance3D in meta.meshes:
 			var dupe = m.duplicate(0)
@@ -711,11 +724,40 @@ func _erase_tp_metadata(node_id: int) -> void:
 	var meta = _watchlist_teleportables.get(node_id)
 	if meta != null:
 		meta = meta as TeleportableMeta
+		
+		if meta.is_player:
+			_set_portal_pair_update_mode(SubViewport.UPDATE_WHEN_VISIBLE)
+			
 		for m in meta.meshes: _disable_mesh_clipping(m)
 		for c in meta.mesh_clones: c.queue_free()
 		
 	_watchlist_teleportables.erase(node_id)
 
+
+func _transfer_tp_metadata_to_exit(for_body: Node3D) -> void:
+	if not exit_portal.is_teleport:
+		return # One-way teleport scenario
+	
+	var body_id = for_body.get_instance_id()
+	var tp_meta = _watchlist_teleportables[body_id]
+	assert(tp_meta != null, "Attempted to trasfer teleport metadata for a node that is not being watched.")
+	
+	tp_meta.forward = exit_portal.forward_distance(for_body)
+	_enable_mesh_clipping(tp_meta, exit_portal) # Switch, the main mesh is clipped by exit portal!
+	
+	exit_portal._watchlist_teleportables.set(body_id, tp_meta)
+	
+	if tp_meta.is_player and exit_portal.exit_portal != self:
+		# Not a portal pair - the transition isn't seamless anyways. Flip the update 
+		# mode of this portal "manually" and enable the next portal pair, since `_construct_tp_metadata`
+		# will not get called there. Usually portals are symmetric, though.
+		portal_viewport.set_update_mode(SubViewport.UPDATE_WHEN_VISIBLE)
+		exit_portal._set_portal_pair_update_mode(SubViewport.UPDATE_ALWAYS)
+	
+	# NOTE: Not using '_erase_tp_metadata' here, as it also frees the cloned meshes!
+	_watchlist_teleportables.erase(body_id)
+
+
 func _enable_mesh_clipping(meta: TeleportableMeta, along_portal: Portal3D) -> void:
 	for mi: MeshInstance3D in meta.meshes:
 		var clip_normal = signf(meta.forward) * along_portal.global_basis.z
@@ -733,23 +775,6 @@ func _enable_mesh_clipping(meta: TeleportableMeta, along_portal: Portal3D) -> vo
 func _disable_mesh_clipping(mi: MeshInstance3D) -> void:
 	mi.set_instance_shader_parameter("portal_clip_active", false)
 
-func _transfer_tp_metadata_to_exit(for_body: Node3D) -> void:
-	if not exit_portal.is_teleport:
-		return # One-way teleport scenario
-	
-	var body_id = for_body.get_instance_id()
-	var tp_meta = _watchlist_teleportables[body_id]
-	if tp_meta == null:
-		push_error("Attempted to trasfer teleport metadata for a node that is not being watched.")
-		return
-	
-	tp_meta.forward = exit_portal.forward_distance(for_body)
-	_enable_mesh_clipping(tp_meta, exit_portal) # Switch, the main mesh is clipped by exit portal!
-	
-	exit_portal._watchlist_teleportables.set(body_id, tp_meta)
-	# NOTE: Not using '_erase_tp_metadata' here, as it also frees the cloned meshes!
-	_watchlist_teleportables.erase(body_id)
-
 ## [b]Crucial[/b] piece of a portal - transforming where objects should appear 
 ## on the other side. Used for both cameras and teleports.
 func to_exit_transform(g_transform: Transform3D) -> Transform3D:
@@ -828,6 +853,12 @@ func _calculate_viewport_size() -> Vector2i:
 func _check_tp_interaction(flag: int) -> bool:
 	return (teleport_interactions & flag) > 0
 
+func _set_portal_pair_update_mode(mode: SubViewport.UpdateMode) -> void:
+	assert(is_instance_valid(exit_portal))
+	self.portal_viewport.set_update_mode(mode)
+	if exit_portal.portal_viewport:
+		exit_portal.portal_viewport.set_update_mode(mode)
+
 ## Get a point where the portal plane intersects a line. Line [param start] and [param end] 
 ## are in global coordinates and so is the result. Used for forwarding raycast queries.
 func line_intersection(start: Vector3, end: Vector3) -> Vector3: