Added region-stepped origin.

scripts/aircraft/nodes/fixed_wing_aircraft.gd

@@ -17,6 +17,8 @@ var m_relative_velocity: Vector3
 
 var m_is_landed := false
 
+@onready var m_region_transform: RegionTransform = $RegionTransform
+
 func _ready() -> void:
     velocity = -global_basis.z * initial_speed
     m_relative_velocity = transform.basis.inverse() * velocity
@@ -77,6 +79,7 @@ func _physics_process(delta: float) -> void:
         rotate_object_local(steering_axis.normalized(), steering_axis.length())
     
     move_and_slide()
+    m_region_transform.sync_from_transform()
     #if !is_landed:
     #    _fly()
     #else:

scripts/origin/region_origin.gd

@@ -0,0 +1,25 @@
+# no name - meant to be an autoload
+# Handles regional origin.
+extends Node
+
+@export var region_size := 1000.0
+@export var origin := Vector3i.ZERO
+@export var anchor: RegionTransform
+
+var nodes_to_move: Dictionary[Node3D, bool]
+
+func _physics_process(_delta: float) -> void:
+    if (anchor and anchor.region != origin):
+        move_origin(anchor.region)
+
+func add_node(new_node: Node3D) -> void:
+    nodes_to_move[new_node] = true
+
+func remove_node(old_node: Node3D) -> void:
+    nodes_to_move.erase(old_node)
+    
+func move_origin(new_origin: Vector3i) -> void:
+    origin = new_origin
+    var move_amount := Vector3(new_origin - origin * 1000)
+    for node in nodes_to_move:
+        node.transform.origin += move_amount

scripts/origin/region_origin.gd.uid

@@ -0,0 +1 @@
+uid://dlrk82k15q6w3

scripts/origin/region_transform.gd

@@ -0,0 +1,36 @@
+class_name RegionTransform
+extends Node
+
+@export var offset: Vector3
+@export var region: Vector3i
+@export var target: Node3D
+
+func _enter_tree() -> void:
+    if not target:
+        target = get_parent()
+    RegionOrigin.add_node(target)
+
+func _exit_tree() -> void:
+    RegionOrigin.remove_node(target)
+
+func move_offset(delta_offset: Vector3) -> void:
+    set_offset(offset + delta_offset)
+
+func set_offset(new_offset: Vector3) -> void:
+    offset = new_offset
+    var delta_sector: Vector3i = _floor_ftoi(new_offset / 1000.0)
+    region += delta_sector
+    offset -= Vector3(delta_sector) * 1000.0
+    sync_to_transform()
+
+func altitude() -> float:
+    return offset.y + float(region.y) * 1000.0
+
+func sync_to_transform() -> void:
+    target.transform.origin = offset + Vector3(region - RegionOrigin.origin)
+
+func sync_from_transform() -> void:
+    set_offset(target.transform.origin)
+
+static func _floor_ftoi(vec: Vector3) -> Vector3i:
+    return Vector3i(int(floorf(vec.x)), int(floorf(vec.y)), int(floorf(vec.z)))

scripts/origin/region_transform.gd.uid

@@ -0,0 +1 @@
+uid://ddh4omp23xc58