diff --git a/data/blender/mitsuba/export/__init__.py b/data/blender/mitsuba/export/__init__.py
index ca948ffe..892ba7a5 100644
--- a/data/blender/mitsuba/export/__init__.py
+++ b/data/blender/mitsuba/export/__init__.py
@@ -458,7 +458,7 @@ class MtsExporter:
 			self.closeElement()
 						
 	def exportMediumReference(self, scene, obj, role, mediumName):
-		if medium == "":
+		if mediumName == "":
 			return
 		if obj.data.users > 1:
 			MtsLog("Error: medium transitions cannot be instantiated (at least for now)!")
@@ -473,10 +473,11 @@ class MtsExporter:
 		mmat = material.mitsuba_material
 		lamp = material.mitsuba_emission
 		if mmat.is_medium_transition:
+			mainScene = bpy.data.scenes[0]
 			if mmat.interior_medium != '':
-				self.exportMedium(scene.mitsuba_media.media[mmat.interior_medium])
+				self.exportMedium(mainScene.mitsuba_media.media[mmat.interior_medium])
 			if mmat.exterior_medium != '':
-				self.exportMedium(scene.mitsuba_media.media[mmat.exterior_medium])
+				self.exportMedium(mainScene.mitsuba_media.media[mmat.exterior_medium])
 		self.openElement('shape', {'id' : 'Exterior-mesh_0', 'type' : 'serialized'})
 		self.parameter('string', 'filename', {'value' : 'matpreview.serialized'})
 		self.parameter('integer', 'shapeIndex', {'value' : '1'})
@@ -512,7 +513,7 @@ class MtsExporter:
 	def exportMedium(self, medium):
 		if medium.name in self.exported_media:
 			return
-		self.exported_media += [mat.name]
+		self.exported_media += [medium.name]
 		self.openElement('medium', {'id' : medium.name, 'type' : medium.type})
 		if medium.g == 0:
 			self.element('phase', {'type' : 'isotropic'})
@@ -520,6 +521,18 @@ class MtsExporter:
 			self.openElement('phase', {'type' : 'hg'})
 			self.parameter('float', 'g', {'value' : str(medium.g)})
 			self.closeElement()
+		if medium.type == 'homogeneous':
+			self.parameter('float', 'densityMultiplier', {'value' :
+				str(medium.densityMultiplier)})
+			self.parameter('rgb', 'sigmaA', {'value' : '%f %f %f' % (
+				(1-medium.albedo.r) * medium.sigmaT[0],
+				(1-medium.albedo.g) * medium.sigmaT[1],
+				(1-medium.albedo.b) * medium.sigmaT[2])})
+			self.parameter('rgb', 'sigmaS', {'value' : '%f %f %f' % (
+				medium.albedo.r * medium.sigmaT[0],
+				medium.albedo.g * medium.sigmaT[1],
+				medium.albedo.b * medium.sigmaT[2])})
+
 		self.closeElement()
 
 	def export(self, scene):
diff --git a/data/blender/mitsuba/properties/integrator.py b/data/blender/mitsuba/properties/integrator.py
index 7f5b61ea..4d552474 100644
--- a/data/blender/mitsuba/properties/integrator.py
+++ b/data/blender/mitsuba/properties/integrator.py
@@ -48,9 +48,9 @@ class mitsuba_integrator(declarative_property_group):
 			'description': 'Specifies the type of integrator to use',
 			'default': 'direct',
 			'items': [
-				('direct', 'Direct Illumination', 'direct'),
+				('volpath', 'Volumetric path tracer', 'volpath'),
 				('path', 'Path tracer', 'path'),
-				('volpath', 'Volumetric path tracer', 'volpath')
+				('direct', 'Direct Illumination', 'direct')
 			],
 			'save_in_preset': True
 		},
diff --git a/data/blender/mitsuba/properties/material.py b/data/blender/mitsuba/properties/material.py
index 11576e50..25441cc5 100644
--- a/data/blender/mitsuba/properties/material.py
+++ b/data/blender/mitsuba/properties/material.py
@@ -93,7 +93,7 @@ class mitsuba_material(declarative_property_group):
 		{
 			'type': 'bool',
 			'attr': 'twosided',
-			'name': 'Use two-sided shading?',
+			'name': 'Use two-sided shading',
 			'description': 'Use two-sided shading for this material? This only makes sense for non-transparent/translucent materials.',
 			'default': False,
 			'save_in_preset': True
@@ -101,7 +101,7 @@ class mitsuba_material(declarative_property_group):
 		{
 			'type': 'bool',
 			'attr': 'is_medium_transition',
-			'name': 'Mark as medium transition?',
+			'name': 'Mark as medium transition',
 			'description': 'Activate this property if the material specifies a transition from one participating medium to another.',
 			'default': False,
 			'save_in_preset': True
@@ -513,7 +513,7 @@ class mitsuba_mat_roughmetal(declarative_property_group):
 			'name' : 'IOR',
 			'description' : 'Per-channel index of refraction of the conductor',
 			'default' : (0.370, 0.370, 0.370),
-			'min': 1.0,
+			'min': 0.1,
 			'max': 10.0,
 			'expand' : False,
 			'save_in_preset': True
diff --git a/data/blender/mitsuba/properties/world.py b/data/blender/mitsuba/properties/world.py
index 81e53e5a..503624f7 100644
--- a/data/blender/mitsuba/properties/world.py
+++ b/data/blender/mitsuba/properties/world.py
@@ -52,9 +52,9 @@ class mitsuba_medium_data(declarative_property_group):
 	ef_attach_to = []	# not attached
 	
 	controls = [
-		'type', 'g'
+		'type', 'g', 'densityMultiplier', 'sigmaT', 'albedo'
 	]
-	
+
 	properties = [
 		{
 			'type': 'enum',
@@ -78,6 +78,41 @@ class mitsuba_medium_data(declarative_property_group):
 			'soft_max': 1.0,
 			'precision': 4,
 			'save_in_preset': True
+		},
+		{
+			'type': 'float',
+			'attr': 'densityMultiplier',
+			'name': 'Density',
+			'description': 'In conjunction with the scattering and absorption coefficients, this number determines the optical density of the medium',
+			'default': 1.0,
+			'min': 0,
+			'max': 10000,
+			'precision': 4,
+			'save_in_preset': True
+		},
+		{
+			'type': 'float_vector',
+			'attr': 'sigmaT',
+			'name' : 'Extinction',
+			'description' : 'Extinction due to scattering and absorption. Please ' +
+				'keep these value roughly equal across color channels (or expect noise).',
+			'default' : (1.0, 1.0, 1.0),
+			'min': 0.0,
+			'max': 1.0,
+			'expand' : False,
+			'save_in_preset': True
+		},
+		{
+			'type': 'float_vector',
+			'attr': 'albedo',
+			'subtype': 'COLOR',
+			'name' : 'Single-scattering albedo',
+			'description' : 'Specifies the albedo of a single scattering interaction',
+			'default' : (0.8, 0.8, 0.8),
+			'min': 0.0,
+			'max': 1.0,
+			'expand' : False,
+			'save_in_preset': True
 		}
 	]