Two-sided area lamps

Shaders/std/ltc.glsl

@@ -158,6 +158,9 @@ float ltcEvaluate(vec3 N, vec3 V, float dotNV, vec3 P, mat3 Minv, vec3 points0,
 	if (n >= 4) sum += integrateEdge(L3, L4);
 	if (n == 5) sum += integrateEdge(L4, L0);
 
-	// return twoSided ? abs(sum) : max(0.0, -sum);
+#ifdef _TwoSidedAreaLamp
+	return abs(sum);
+#else
 	return max(0.0, -sum);
+#endif
 }

blender/arm/make_world.py

@@ -71,6 +71,9 @@ def build_node_tree(world):
     if wrd.generate_ssrs:
         wrd.world_defs += '_SSRS'
 
+    if wrd.generate_two_sided_area_lamp:
+        wrd.world_defs += '_TwoSidedAreaLamp'
+
     # Alternative models
     if wrd.lighting_model == 'Cycles':
         wrd.world_defs += '_Cycles'

blender/arm/props.py

@@ -468,6 +468,7 @@ def init_properties():
                ('Auto', 'Auto', 'Auto')],
         name="Anisotropic Filtering", description="Texture filtering", default='On')
     bpy.types.World.force_no_culling = bpy.props.BoolProperty(name="Force No Culling", default=False)
+    bpy.types.World.generate_two_sided_area_lamp = bpy.props.BoolProperty(name="Two-Sided Area Lamps", description="Emit light from both faces of area lamp", default=False, update=assets.invalidate_shader_cache)
     bpy.types.World.tessellation_enabled = bpy.props.BoolProperty(name="Tessellation", description="Enable tessellation for height maps on supported targets", default=True, update=assets.invalidate_shader_cache)
     # Lighting flags
     bpy.types.World.lighting_model = EnumProperty(

blender/arm/props_renderer.py

@@ -284,6 +284,7 @@ class PropsRPDataPropsPanel(bpy.types.Panel):
             layout.prop(wrd, 'anisotropic_filtering_state')
             layout.prop(wrd, 'tessellation_enabled')
             layout.prop(wrd, 'force_no_culling')
+            layout.prop(wrd, 'generate_two_sided_area_lamp')
             
             layout.prop(wrd, 'arm_camera_props_advanced')
             if wrd.arm_camera_props_advanced: