feat: add native road compiler provider

blender/export_cesium.py

@@ -657,6 +657,8 @@ def export(args):
             raise RuntimeError("Dynamic traffic signal collection is empty")
         export_glb(args["dynamic_glb"], dynamic_meshes)
     for group, key in ((0, "countdown_0_glb"), (1, "countdown_1_glb")):
+        if not args.get(key):
+            continue
         if not countdown_meshes[group]:
             raise RuntimeError("Traffic countdown collection %d is empty" % group)
         export_glb(args[key], countdown_meshes[group])

blender/generate_scene.py

@@ -110,7 +110,7 @@ TREE_STYLES = frozenset(("natural", "procedural")) | frozenset(_tree.MODEL_STYLE
 
 
 def cli_args():
-    values = {"osm": None, "geojson": None, "output": None, "render": None,
+    values = {"osm": None, "geojson": None, "native_road": None, "output": None, "render": None,
               "office_overrides": "", "tree_style": "natural"}
     argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
     i = 0
@@ -789,8 +789,23 @@ def build(args):
     _features.dispatch_ways(ways, projector, way_handlers)
 
     geojson_dir = args.get("geojson")
+    native_road_dir = args.get("native_road")
     road_counts = {}
-    if geojson_dir and os.path.isdir(geojson_dir):
+    if native_road_dir:
+        if not os.path.isdir(native_road_dir):
+            raise RuntimeError("--native-road directory does not exist: " + native_road_dir)
+        material_layers = {layer["id"]: layer for layer in catalog.ROAD_LAYERS}
+        for source in catalog.NATIVE_ROAD_LAYERS:
+            target = source["material_layer"]
+            layer = material_layers[target]
+            source_path = os.path.join(native_road_dir, "layers", source["source"] + ".geojson")
+            count = _roads.assemble_geojson_layer(
+                source_path, source["source"], projector, roads_c,
+                road_mats[target], layer["z"])
+            if count == 0:
+                raise RuntimeError("Native road layer has no usable geometry: " + source_path)
+            road_counts[source["source"]] = count
+    elif geojson_dir and os.path.isdir(geojson_dir):
         for problem in catalog.check_layers(geojson_dir):
             print("Layer catalog warning:", problem)
         for layer in catalog.ROAD_LAYERS:
@@ -799,7 +814,7 @@ def build(args):
                 os.path.join(geojson_dir, layer_id + ".geojson"), layer_id,
                 projector, roads_c, road_mats[layer_id], layer["z"])
 
-    if road_counts.get("road_surface", 0) == 0:
+    if not native_road_dir and road_counts.get("road_surface", 0) == 0:
         _roads.assemble_osm_fallback(
             ways, projector, roads_c, road_mats["road_surface"])
 
@@ -910,6 +925,7 @@ def build(args):
     scene.render.filepath = args["render"]
     scene["source_osm"] = args["osm"]
     scene["source_geojson"] = geojson_dir or ""
+    scene["source_native_road"] = native_road_dir or ""
     scene["osm_bounds"] = json.dumps(bounds, ensure_ascii=True)
     scene["building_count"] = counts["building_count"]
     scene["industrial_building_count"] = counts["industrial_count"]

blender/osmassets/catalog.py

@@ -48,6 +48,14 @@ ROAD_LAYERS = [
 
 SCENE_STYLE_FILE = "osm2streets_scene_style.json"
 
+# Native-road output intentionally maps into existing scene material layers.
+# It is a provider adapter, not a second scene-layer registry.
+NATIVE_ROAD_LAYERS = (
+    {"source": "road_surface", "material_layer": "road_surface"},
+    {"source": "intersection_surface", "material_layer": "intersection_surface"},
+    {"source": "sidewalk_surface", "material_layer": "sidewalks"},
+)
+
 
 # Material specs.  `kind` selects the builder:
 #   solid      — flat base colour

blender/tests/test_pure.py

@@ -30,7 +30,7 @@ from osmassets.geom import (
     sample_tree_row,
     signed_polygon_area,
 )
-from osmassets.catalog import ROAD_LAYERS
+from osmassets.catalog import NATIVE_ROAD_LAYERS, ROAD_LAYERS
 from osmassets.osm import Projector, parse_height, parse_osm, tags
 
 
@@ -46,6 +46,24 @@ class RoadLayerCatalogTest(unittest.TestCase):
         self.assertNotEqual(layers["road_surface"]["z"],
                             layers["intersection_surface"]["z"])
 
+    def test_native_provider_maps_to_existing_material_layers(self):
+        layers = {layer["id"] for layer in ROAD_LAYERS}
+        self.assertEqual(
+            [(entry["source"], entry["material_layer"])
+             for entry in NATIVE_ROAD_LAYERS],
+            [("road_surface", "road_surface"),
+             ("intersection_surface", "intersection_surface"),
+             ("sidewalk_surface", "sidewalks")])
+        self.assertTrue(all(entry["material_layer"] in layers
+                            for entry in NATIVE_ROAD_LAYERS))
+
+    def test_cesium_export_keeps_signal_assets_optional(self):
+        exporter = os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                                "..", "export_cesium.py")
+        with open(exporter, encoding="utf-8") as handle:
+            source = handle.read()
+        self.assertIn('if not args.get(key):\n            continue', source)
+
 
 class GeometryRingsTest(unittest.TestCase):
     def test_polygon_keeps_only_the_exterior_ring(self):