Improve OMI_seat, add new node type for Area3D-derived seats

addons/omi_extensions/omi_extensions_plugin.gd

@@ -2,12 +2,21 @@
 extends EditorPlugin
 
 
+var seat_gizmo_plugin = EditorSeat3DGizmoPlugin.new()
+
+
 func _enter_tree() -> void:
 	# NOTE: Be sure to also instance and register these at runtime if you want
 	# the extensions at runtime. This editor plugin script won't run in games.
-	var ext = GLTFDocumentExtensionOMISeat.new()
-	GLTFDocument.register_gltf_document_extension(ext)
+	var ext: GLTFDocumentExtension
+	ext = GLTFDocumentExtensionOMISeat.new()
+	GLTFDocument.register_gltf_document_extension(ext, true)
 	ext = GLTFDocumentExtensionOMISpawnPoint.new()
 	GLTFDocument.register_gltf_document_extension(ext)
 	ext = GLTFDocumentExtensionOMIPhysicsJoint.new()
 	GLTFDocument.register_gltf_document_extension(ext)
+	add_node_3d_gizmo_plugin(seat_gizmo_plugin)
+
+
+func _exit_tree():
+	remove_node_3d_gizmo_plugin(seat_gizmo_plugin)

addons/omi_extensions/misc/omi_seat.gd → addons/omi_extensions/seat/omi_seat_doc_ext.gd

@@ -3,6 +3,7 @@ class_name GLTFDocumentExtensionOMISeat
 extends GLTFDocumentExtension
 
 
+# Import process.
 func _import_preflight(_state: GLTFState, extensions: PackedStringArray) -> Error:
 	if extensions.has("OMI_seat"):
 		return OK
@@ -13,27 +14,46 @@ func _get_supported_extensions() -> PackedStringArray:
 	return PackedStringArray(["OMI_seat"])
 
 
-func _import_node(_state: GLTFState, _gltf_node: GLTFNode, json: Dictionary, node: Node) -> Error:
-	if not json.has("extensions"):
-		return OK
-	var extensions = json.get("extensions")
-	if not extensions is Dictionary:
-		printerr("Error: GLTF file is invalid, extensions should be a Dictionary.")
-		return ERR_FILE_CORRUPT
+func _parse_node_extensions(state: GLTFState, gltf_node: GLTFNode, extensions: Dictionary) -> Error:
 	if not extensions.has("OMI_seat"):
 		return OK
-	var seat_dict = extensions.get("OMI_seat")
+	var seat_dict = extensions["OMI_seat"]
 	if not seat_dict is Dictionary:
 		printerr("Error: OMI_seat extension should be a Dictionary.")
 		return ERR_FILE_CORRUPT
-	if convert_seat(seat_dict):
-		node.set_meta(&"OMI_seat", seat_dict)
-	else:
+	if not _convert_seat_dict(seat_dict):
 		return ERR_FILE_CORRUPT
+	gltf_node.set_additional_data(&"OMI_seat", seat_dict)
 	return OK
 
 
-static func convert_seat(seat_dict: Dictionary) -> bool:
+func _generate_scene_node(state: GLTFState, gltf_node: GLTFNode, scene_parent: Node) -> Node3D:
+	var seat_dict = gltf_node.get_additional_data(&"OMI_seat")
+	if seat_dict == null:
+		return null
+	# If this node is both a seat and a glTF trigger, generate the Area3D-derived Seat3D node.
+	# Else, if this is not any kind of trigger, don't generate a Seat3D/Area3D, just set node metadata later.
+	var trigger = gltf_node.get_additional_data(&"GLTFPhysicsTrigger")
+	if trigger == null:
+		trigger = gltf_node.get_additional_data(&"GLTFPhysicsCompoundTriggerNodes")
+		if trigger == null:
+			trigger = gltf_node.get_additional_data(&"GLTFPhysicsBody")
+			if trigger == null:
+				return null
+			if trigger.body_type != "trigger":
+				return null
+	return Seat3D.from_points(seat_dict["back"], seat_dict["foot"], seat_dict["knee"], seat_dict.get("angle", TAU * 0.25))
+
+
+func _import_node(_state: GLTFState, gltf_node: GLTFNode, json: Dictionary, node: Node) -> Error:
+	var seat_dict = gltf_node.get_additional_data(&"OMI_seat")
+	if seat_dict != null:
+		node.set_meta(&"OMI_seat", seat_dict)
+	return OK
+
+
+static func _convert_seat_dict(seat_dict: Dictionary) -> bool:
+	# The JSON data has Vector3s represented as arrays, let's convert them to Vector3.
 	if not _convert_seat_vector(seat_dict, "foot"):
 		return false
 	if not _convert_seat_vector(seat_dict, "knee"):
@@ -80,29 +100,45 @@ static func _calculate_helper_vectors(seat_dict: Dictionary) -> void:
 	seat_dict["lower_leg_norm"] = lower_leg_norm
 
 
+# Export process.
 func _export_node(state: GLTFState, _gltf_node: GLTFNode, json: Dictionary, node: Node) -> Error:
-	if node.has_meta(&"OMI_seat"):
-		var omi_seat_ext: Dictionary = _export_omi_seat(node.get_meta(&"OMI_seat"))
-		# Write to the GLTF node JSON.
-		var extensions: Dictionary
-		if "extensions" in json:
-			extensions = json["extensions"]
-		else:
-			extensions = {}
-			json["extensions"] = extensions
-		extensions["OMI_seat"] = omi_seat_ext
-		state.add_used_extension("OMI_seat", false)
+	var omi_seat_ext: Dictionary = _export_omi_seat_from_node(node)
+	if omi_seat_ext.is_empty():
+		return OK
+	# Write to the GLTF node JSON.
+	var extensions: Dictionary
+	if "extensions" in json:
+		extensions = json["extensions"]
+	else:
+		extensions = {}
+		json["extensions"] = extensions
+	extensions["OMI_seat"] = omi_seat_ext
+	state.add_used_extension("OMI_seat", false)
 	return OK
 
 
-func _export_omi_seat(omi_seat_meta: Dictionary) -> Dictionary:
-	var back: Vector3 = omi_seat_meta["back"]
-	var foot: Vector3 = omi_seat_meta["foot"]
-	var knee: Vector3 = omi_seat_meta["knee"]
+func _export_omi_seat_from_node(node: Node) -> Dictionary:
 	var omi_seat_ext: Dictionary = {}
+	var back: Vector3
+	var foot: Vector3
+	var knee: Vector3
+	var angle: float
+	if node is Seat3D:
+		back = node.back
+		foot = node.foot
+		knee = node.knee
+		angle = node.angle
+	elif node.has_meta(&"OMI_seat"):
+		var omi_seat_meta = node.get_meta(&"OMI_seat")
+		back = omi_seat_meta["back"]
+		foot = omi_seat_meta["foot"]
+		knee = omi_seat_meta["knee"]
+		angle = omi_seat_meta["angle"]
+	else:
+		return omi_seat_ext
 	omi_seat_ext["back"] = [back.x, back.y, back.z]
 	omi_seat_ext["foot"] = [foot.x, foot.y, foot.z]
 	omi_seat_ext["knee"] = [knee.x, knee.y, knee.z]
-	if not is_equal_approx(omi_seat_meta["angle"], TAU * 0.25):
-		omi_seat_ext["angle"] = omi_seat_meta["angle"]
+	if not is_equal_approx(angle, TAU * 0.25):
+		omi_seat_ext["angle"] = angle
 	return omi_seat_ext

addons/omi_extensions/seat/seat_3d.gd

@@ -0,0 +1,115 @@
+## Defines a seat using a set of control points. Characters can sit on this seat by interacting with it.
+@tool
+class_name Seat3D
+extends Area3D
+
+
+## The character occupying the seat, if any. This is expected to be assigned at runtime.
+## Change the type if your characters do not inherit CharacterBody3D.
+var occupant: CharacterBody3D
+
+var _back := Vector3(0.0, 0.0, -0.25)
+## The seat position control point corresponding to the character's back position.
+@export_custom(PROPERTY_HINT_NONE, "suffix:m")
+var back := Vector3(0.0, 0.0, -0.25):
+	get:
+		return _back
+	set(value):
+		_back = value
+		_recalculate_helper_vectors()
+
+var _foot := Vector3(0.0, -0.5, 0.25)
+## The seat position control point corresponding to the character's foot position.
+@export_custom(PROPERTY_HINT_NONE, "suffix:m")
+var foot := Vector3(0.0, -0.5, 0.25):
+	get:
+		return _foot
+	set(value):
+		_foot = value
+		_recalculate_helper_vectors()
+
+var _knee := Vector3(0.0, 0.0, 0.25)
+## The seat position control point corresponding to the character's knee position.
+@export_custom(PROPERTY_HINT_NONE, "suffix:m")
+var knee := Vector3(0.0, 0.0, 0.25):
+	get:
+		return _knee
+	set(value):
+		_knee = value
+		_recalculate_helper_vectors()
+
+var _angle: float = TAU * 0.25
+## The seat angle between the spine and the back-knee line. Recommended values are close to 90 degrees, and going over is better than going under.
+@export_range(10.0, 180.0, 0.1, "radians_as_degrees")
+var angle: float = TAU * 0.25:
+	get:
+		return _angle
+	set(value):
+		_angle = value
+		_recalculate_helper_vectors()
+
+var _right := Vector3.ZERO
+var _spine_dir := Vector3.ZERO
+var _spine_norm := Vector3.ZERO
+var _upper_leg_dir := Vector3.ZERO
+var _upper_leg_norm := Vector3.ZERO
+var _lower_leg_dir := Vector3.ZERO
+var _lower_leg_norm := Vector3.ZERO
+
+
+func _init() -> void:
+	_recalculate_helper_vectors()
+
+
+func get_right() -> Vector3:
+	return _right
+
+
+func get_spine_dir() -> Vector3:
+	return _spine_dir
+
+
+func get_spine_norm() -> Vector3:
+	return _spine_norm
+
+
+func get_upper_leg_dir() -> Vector3:
+	return _upper_leg_dir
+
+
+func get_upper_leg_norm() -> Vector3:
+	return _upper_leg_norm
+
+
+func get_lower_leg_dir() -> Vector3:
+	return _lower_leg_dir
+
+
+func get_lower_leg_norm() -> Vector3:
+	return _lower_leg_norm
+
+
+func set_points(p_back: Vector3, p_foot: Vector3, p_knee: Vector3, p_angle: float = TAU * 0.25) -> void:
+	_back = p_back
+	_foot = p_foot
+	_knee = p_knee
+	_angle = p_angle
+	_recalculate_helper_vectors()
+
+
+func _recalculate_helper_vectors() -> void:
+	_upper_leg_dir = back.direction_to(knee)
+	_lower_leg_dir = knee.direction_to(foot)
+	_right = _lower_leg_dir.cross(_upper_leg_dir).normalized()
+	if _right == Vector3.ZERO:
+		return
+	_spine_dir = _upper_leg_dir.rotated(_right, angle)
+	_spine_norm = _spine_dir.cross(_right)
+	_upper_leg_norm = _right.cross(_upper_leg_dir)
+	_lower_leg_norm = _right.cross(_lower_leg_dir)
+
+
+static func from_points(p_back: Vector3, p_foot: Vector3, p_knee: Vector3, p_angle: float = TAU * 0.25) -> Seat3D:
+	var seat = Seat3D.new()
+	seat.set_points(p_back, p_foot, p_knee, p_angle)
+	return seat