feat(nav2): load custom editor layouts in gazebo

src/nav2_turtlebot_simulator/launch/simulator.launch.py

@@ -1,3 +1,4 @@
+import json
 import os
 import tempfile
 import xml.etree.ElementTree as ET
@@ -76,6 +77,59 @@ def create_flat_house_world(gazebo_dir):
     return flat_world_path
 
 
+def create_custom_layout_world():
+    """Build a Gazebo world from the editor's persisted 2D layout."""
+    layout_path = os.environ.get('WORLD_LAYOUT_PATH', '/modules/world-layout.json')
+    try:
+        with open(layout_path, 'r', encoding='utf-8') as source:
+            objects = json.load(source).get('objects', [])
+    except (OSError, ValueError, AttributeError):
+        objects = []
+
+    models = []
+    for index, item in enumerate(objects):
+        if not isinstance(item, dict):
+            continue
+        position = item.get('position') or [0, 0, 0]
+        rotation = item.get('rotation') or [0, 0, 0]
+        size = item.get('size') or [1, 1, 1]
+        try:
+            x, y, z = (float(position[0]), float(position[1]), float(position[2]))
+            yaw = float(rotation[2])
+            sx, sy, sz = (max(0.05, float(size[0])), max(0.05, float(size[1])), max(0.05, float(size[2])))
+        except (IndexError, TypeError, ValueError):
+            continue
+
+        name = f"custom_{item.get('type', 'box')}_{index}"
+        if item.get('type') == 'pillar':
+            geometry = f'<cylinder><radius>{sx / 2.0}</radius><length>{sz}</length></cylinder>'
+        else:
+            geometry = f'<box><size>{sx} {sy} {sz}</size></box>'
+        models.append(
+            f'''<model name="{name}">
+  <static>true</static>
+  <pose>{x} {y} {z} 0 0 {yaw}</pose>
+  <link name="link">
+    <collision name="collision"><geometry>{geometry}</geometry></collision>
+    <visual name="visual"><geometry>{geometry}</geometry><material><ambient>0.34 0.58 0.82 1</ambient><diffuse>0.34 0.58 0.82 1</diffuse></material></visual>
+  </link>
+</model>'''
+        )
+
+    world_path = os.path.join(tempfile.gettempdir(), 'nav2_custom_layout.world')
+    with open(world_path, 'w', encoding='utf-8') as destination:
+        destination.write('''<?xml version="1.0"?>
+<sdf version="1.6">
+  <world name="nav2_custom_layout">
+    <include><uri>model://sun</uri></include>
+    <include><uri>model://ground_plane</uri></include>
+    <physics type="ode"><real_time_update_rate>1000</real_time_update_rate></physics>
+''')
+        destination.write('\n'.join(models))
+        destination.write('\n  </world>\n</sdf>\n')
+    return world_path
+
+
 def launch_gazebo(context):
     gazebo_dir = get_package_share_directory('turtlebot3_gazebo')
     simulator_dir = get_package_share_directory('nav2_turtlebot_simulator')
@@ -86,7 +140,9 @@ def launch_gazebo(context):
     if render_mode not in {'flat', 'full'}:
         raise RuntimeError('render_mode must be either flat or full')
 
-    if world == 'turtlebot3_house.world' and render_mode == 'flat':
+    if world == 'empty_world.world' and os.path.isfile(os.environ.get('WORLD_LAYOUT_PATH', '/modules/world-layout.json')):
+        world_path = create_custom_layout_world()
+    elif world == 'turtlebot3_house.world' and render_mode == 'flat':
         world_path = create_flat_house_world(gazebo_dir)
     else:
         world_path = os.path.join(