From b61d8709225cfb3020fc40731dec7696ddec34bb Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Wed, 10 Apr 2024 10:36:51 +1000
Subject: [PATCH] See #4481. Defer setting render visibility to drawing
 generation to speed up switching between drawings.

Doing obj.hide_render = True/False in a loop is slow and there is no bulk set command.
---
 .../blenderbim/bim/module/drawing/operator.py |  5 ++++
 src/blenderbim/blenderbim/tool/drawing.py     | 28 ++++++-------------
 2 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/src/blenderbim/blenderbim/bim/module/drawing/operator.py b/src/blenderbim/blenderbim/bim/module/drawing/operator.py
index 6d02ca5aa2..9a275e5018 100644
--- a/src/blenderbim/blenderbim/bim/module/drawing/operator.py
+++ b/src/blenderbim/blenderbim/bim/module/drawing/operator.py
@@ -341,6 +341,11 @@ class CreateDrawing(bpy.types.Operator):
         if not ifcopenshell.util.element.get_pset(self.drawing, "EPset_Drawing", "HasUnderlay"):
             return
         svg_path = self.get_svg_path(cache_type="underlay")
+
+        visible_object_names = {obj.name for obj in bpy.context.visible_objects}
+        for obj in bpy.context.view_layer.objects:
+            obj.hide_render = obj.name not in visible_object_names
+
         context.scene.render.filepath = svg_path[0:-4] + ".png"
         drawing_style = context.scene.DocProperties.drawing_styles[self.cprops.active_drawing_style_index]
 
diff --git a/src/blenderbim/blenderbim/tool/drawing.py b/src/blenderbim/blenderbim/tool/drawing.py
index 6d91dd2459..a14a2f7337 100644
--- a/src/blenderbim/blenderbim/tool/drawing.py
+++ b/src/blenderbim/blenderbim/tool/drawing.py
@@ -1716,20 +1716,6 @@ class Drawing(blenderbim.core.tool.Drawing):
 
         filtered_elements = cls.get_drawing_elements(drawing) | cls.get_drawing_spaces(drawing)
         filtered_elements.add(drawing)
-        # Hide everything first, then selectively show. This is significantly faster.
-        with bpy.context.temp_override(area=next(a for a in bpy.context.screen.areas if a.type == "VIEW_3D")):
-            bpy.ops.object.hide_view_set(unselected=False)
-            bpy.ops.object.hide_view_set(unselected=True)
-
-        for view_layer_object in bpy.context.view_layer.objects:
-            element = tool.Ifc.get_entity(view_layer_object)
-            if not element or element.is_a("IfcTypeProduct"):
-                continue
-            if element in filtered_elements:
-                view_layer_object.hide_set(False)
-                view_layer_object.hide_render = False
-            elif view_layer_object.hide_render is not True:
-                view_layer_object.hide_render = True
 
         subcontexts: list[ifcopenshell.entity_instance] = []
         target_view = cls.get_drawing_target_view(drawing)
@@ -1764,6 +1750,11 @@ class Drawing(blenderbim.core.tool.Drawing):
             if subcontext:
                 subcontexts.append(context_filter)
 
+        # Hide everything first, then selectively show. This is significantly faster.
+        with bpy.context.temp_override(area=next(a for a in bpy.context.screen.areas if a.type == "VIEW_3D")):
+            bpy.ops.object.hide_view_set(unselected=False)
+            bpy.ops.object.hide_view_set(unselected=True)
+
         # switch representations and hide elements without representations
         for element in filtered_elements:
             obj = tool.Ifc.get_object(element)
@@ -1793,11 +1784,10 @@ class Drawing(blenderbim.core.tool.Drawing):
                     has_context = True
                     break
 
-            # don't hide IfcAnnotations as some of them might exist without representations
-            # e.g. with ObjectType = SYMBOL
-            if not has_context and not element.is_a("IfcAnnotation"):
-                obj.hide_set(True)
-                obj.hide_render = True
+            # Don't hide IfcAnnotations as some of them might exist without representations
+            if has_context or element.is_a("IfcAnnotation"):
+                # Note that render visibility is only set on drawing generation time for speed.
+                obj.hide_set(False)
 
     @classmethod
     def get_elements_in_camera_view(