feat: 草坪新增一些草

blender/export_cesium.py

@@ -250,6 +250,11 @@ def make_export_material(material):
 def unwrap_mesh(obj):
     if obj.type != "MESH" or not obj.data.polygons:
         return
+    # Imported assets ship authored UVs that map onto their own texture atlas;
+    # smart_project would scramble the leaves. Only the procedurally built
+    # meshes arrive without a UV layer, so that is the reliable discriminator.
+    if obj.data.uv_layers:
+        return
     bpy.ops.object.select_all(action="DESELECT")
     obj.select_set(True)
     bpy.context.view_layer.objects.active = obj
@@ -281,6 +286,7 @@ def export(args):
 
     material_map = {}
     meshes = []
+    unwrapped = set()
     for obj in bpy.context.scene.objects:
         if obj.type != "MESH":
             continue
@@ -290,7 +296,11 @@ def export(args):
             continue
         meshes.append(obj)
         apply_mesh_modifiers(obj)
-        unwrap_mesh(obj)
+        # Hundreds of grass tufts share four mesh datablocks; unwrapping is a
+        # property of the mesh, so doing it once per datablock is enough.
+        if obj.data.name not in unwrapped:
+            unwrapped.add(obj.data.name)
+            unwrap_mesh(obj)
         for slot in obj.material_slots:
             if not slot.material:
                 continue