Merge branch 'blender-v2.81-release'

2 files changed, 8 insertions, 7 deletions

diff --git a/intern/cycles/blender/blender_object.cpp b/intern/cycles/blender/blender_object.cpp
index 5520cfd5ecf..6981412bb88 100644
--- a/intern/cycles/blender/blender_object.cpp
+++ b/intern/cycles/blender/blender_object.cpp
@@ -269,6 +269,9 @@ void BlenderSync::sync_background_light(BL::SpaceView3D &b_v3d, bool use_portal)
         light->use_mis = sample_as_light;
         light->max_bounces = get_int(cworld, "max_bounces");
 
+        /* force enable light again when world is resynced */
+        light->is_enabled = true;
+
         int samples = get_int(cworld, "samples");
         if (get_boolean(cscene, "use_square_samples"))
           light->samples = samples * samples;
diff --git a/intern/cycles/render/light.cpp b/intern/cycles/render/light.cpp
index 8c7a21da561..dc3f7c8f8ac 100644
--- a/intern/cycles/render/light.cpp
+++ b/intern/cycles/render/light.cpp
@@ -221,13 +221,11 @@ void LightManager::disable_ineffective_light(Scene *scene)
      */
     Shader *shader = (scene->background->shader) ? scene->background->shader :
                                                    scene->default_background;
-    bool disable_mis = !(has_portal || shader->has_surface_spatial_varying);
-    if (disable_mis) {
-      VLOG(1) << "Background MIS has been disabled.\n";
-      foreach (Light *light, scene->lights) {
-        if (light->type == LIGHT_BACKGROUND) {
-          light->is_enabled = false;
-        }
+    const bool disable_mis = !(has_portal || shader->has_surface_spatial_varying);
+    VLOG_IF(1, disable_mis) << "Background MIS has been disabled.\n";
+    foreach (Light *light, scene->lights) {
+      if (light->type == LIGHT_BACKGROUND) {
+        light->is_enabled = !disable_mis;
       }
     }
   }