make it possible to disable area light visibility for indirect rays

export/light.py

@@ -317,10 +317,12 @@ def _convert_area_lamp(obj, scene, context, luxcore_scene, gain, importance, lux
         "emission.theta": math.degrees(lamp.luxcore.spread_angle),
         "emission.id": scene.luxcore.lightgroups.get_id_by_name(lamp.luxcore.lightgroup),
         "emission.importance": importance,
-        # TODO: maybe transparency (hacky)
-
-        # Note: do not add support for visibility.indirect.* settings, they are useless here
-        # because the only sensible setting is to have them enabled, otherwise we lose MIS
+        # TODO: transparency
+        # Note: if any of these is disabled, we lose MIS, which can lead to more noise.
+        # However, in some rare cases it's needed to disable some of them.
+        "visibility.indirect.diffuse.enable": lamp.luxcore.visibility_indirect_diffuse,
+        "visibility.indirect.glossy.enable": lamp.luxcore.visibility_indirect_glossy,
+        "visibility.indirect.specular.enable": lamp.luxcore.visibility_indirect_specular,
     }
 
     # IES data

properties/light.py

@@ -172,7 +172,7 @@ def update_is_laser(self, context):
     # laser
     # Note: radius is set with default Blender properties (area light size)
 
-    # sky2, sun, infinite, constantinfinite
+    # sky2, sun, infinite, constantinfinite, area
     visibility_indirect_diffuse = BoolProperty(name="Diffuse", default=True, description=VIS_INDIRECT_DIFFUSE_DESC)
     visibility_indirect_glossy = BoolProperty(name="Glossy", default=True, description=VIS_INDIRECT_GLOSSY_DESC)
     visibility_indirect_specular = BoolProperty(name="Specular", default=True, description=VIS_INDIRECT_SPECULAR_DESC)

ui/light.py

@@ -193,16 +193,17 @@ class LUXCORE_LAMP_PT_visibility(DataButtonsPanel, Panel):
     @classmethod
     def poll(cls, context):
         engine = context.scene.render.engine
+        if engine != "LUXCORE":
+            return False
 
-        visible = False
-        if context.lamp:
-            # Visible for sky2, sun, infinite, constantinfinite
-            if context.lamp.type == "SUN" and context.lamp.luxcore.sun_type == "sun":
-                visible = True
-            elif context.lamp.type == "HEMI":
-                visible = True
+        light = context.lamp
+        if not light:
+            return False
 
-        return context.lamp and engine == "LUXCORE" and visible
+        # Visible for sky2, sun, infinite, constantinfinite, area
+        return ((light.type == "SUN" and light.luxcore.sun_type == "sun")
+                or light.type == "HEMI"
+                or (light.type == "AREA" and not light.luxcore.is_laser))
 
     def draw(self, context):
         layout = self.layout