See #7133. Sync viewport visibility with render visibility when generating underlays.

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -443,6 +443,8 @@ class CreateDrawing(bpy.types.Operator):
         context.scene.render.filepath = str(Path(svg_path).with_suffix(".png"))
         assert (drawing_style := self.cprops.get_active_drawing_style())
 
+        tool.Blender.sync_render_visibility()
+
         if drawing_style.render_type == "DEFAULT":
             bpy.ops.render.render(write_still=True)
         else:

src/bonsai/bonsai/tool/blender.py

@@ -1889,6 +1889,24 @@ class Blender(bonsai.core.tool.Blender):
                 obj.select_set(True)
         bpy.context.view_layer.objects.active = previously_active
 
+    @classmethod
+    def sync_render_visibility(cls):
+        # Doing bpy.ops.object.hide_render_clear_all() or
+        # bpy.ops.object.isolate_type_render() is extremely slow.
+        # Hopefully this doesn't crash on Windows, it doesn't crash on Linux.
+        should_hides = [0 if obj.visible_get() else 1 for obj in bpy.data.objects]
+        should_hides = np.fromiter(should_hides, dtype=np.uint8, count=len(should_hides))
+        bpy.data.objects.foreach_set("hide_render", should_hides)
+        return # Otherwise...
+        # for obj in bpy.data.objects:
+        #     if not obj.data:
+        #         continue
+        #     # For speed, check equality prior to change to prevent needless updates
+        #     if (is_visible := obj.visible_get()) and obj.hide_render is True:
+        #         obj.hide_render = False
+        #     elif not is_visible and obj.hide_render is False:
+        #         obj.hide_render = True
+
     @classmethod
     def hide_objects(cls, objs):
         previously_selected = {o.name for o in bpy.context.selected_objects}