merge with default branch

.hgignore

@@ -11,8 +11,9 @@
 .*moc_.*\.cc$
 .*qrc_.*\.cc$
 
-# SCons-related
+# Build-related
 ^\.sconf_temp/.*$
+^debian/.*$
 ^.sconsign.dblite$
 ^config.py$
 ^config.log$

doc/compiling.tex

@@ -52,11 +52,11 @@ using another distribution.
 
 First, run
 \begin{shell}
-$\text{\$}$ apt-get install build-essential scons qt4-dev-tools scons libpng12-dev libjpeg62-dev libilmbase-dev libopenexr-dev libxerces-c-dev libboost-dev libglewmx1.5-dev libxxf86vm-dev libboost-system-dev libboost-filesystem-dev
+$\text{\$}$ sudo apt-get install build-essential scons qt4-dev-tools scons libpng12-dev libjpeg62-dev libilmbase-dev libopenexr-dev libxerces-c-dev libboost-dev libglewmx1.5-dev libxxf86vm-dev libboost-system-dev libboost-filesystem-dev
 \end{shell}
 To get COLLADA support, you will also need to install the \texttt{collada-dom} packages or build them from scratch. Here, we install the \code{x86\_64} binaries and development headers included with Mitsuba:
 \begin{shell}
-$\text{\$}$ dpkg --install tools/linux/collada-dom2.2_2.2-1_amd64.deb tools/linux/collada-dom-dev_2.2-1_amd64.deb
+$\text{\$}$ sudo dpkg --install tools/linux/collada-dom2.2_2.2-1_amd64.deb tools/linux/collada-dom-dev_2.2-1_amd64.deb
 \end{shell}
 Afterwards, simply run
 \begin{shell}
@@ -82,7 +82,38 @@ First, run
 \begin{shell}
 $\text{\$}$ yum install mercurial gcc-c++ scons boost-devel qt4-devel OpenEXR-devel xerces-c-devel
 \end{shell}
-You will also need the \texttt{glew-mx} and \texttt{collada-dom} packages, which are not included in the Fedora package repository. You can grab source and \texttt{i386} binary \texttt{RPM} files here: \texttt{http://www.mitsuba-renderer.org/releases}.
+You will also need the \texttt{glew-mx} and \texttt{collada-dom} packages, which are not included in the Fedora package repository. 
+You can grab source, \texttt{i386}, and \text{x86\_64} \texttt{RPM} files here: \texttt{http://www.mitsuba-renderer.org/releases}.
+Afterwards, simply run
+\begin{shell}
+$\text{\$}$ scons
+\end{shell}
+inside the Mitsuba directory. In the case that you have multiple processors, you might want to parallelize the build by appending \code{-j }\emph{core count} to the command.
+If all goes well, SCons should finish successfully within a few minutes:
+\begin{shell}
+scons: $\texttt{done}$ building targets.
+\end{shell}
+To be able to run the renderer from the command line, you will also have to import it into your path:
+\begin{shell}
+$\text{\$}$ . setpath.sh
+\end{shell}
+(note the period at the beginning -- this assumes that you are using \code{bash}).
+
+\subsection{Building on Arch Linux}
+You'll first need to install a number of dependencies.
+
+First, run
+\begin{shell}
+$\text{\$}$ pacman -S mercurial openexr gcc xerces-c boost libjpeg libpng qt libxmu libxi mesa pcre libxml2 scons
+\end{shell}
+Some of the extra dependencies must be built manually:
+\begin{shell}
+$\text{\$}$ wget https://www.mitsuba-renderer.org/releases/contrib/archlinux/glewmx/PKGBUILD
+$\text{\$}$ makepkg
+$\text{\$}$ sudo pacman -U glewmx-*.xz
+\end{shell}
+and similar for \texttt{https://www.mitsuba-renderer.org/releases/contrib/archlin}-
+\texttt{ux/collada-dom/PKGBUILD}.
 Afterwards, simply run
 \begin{shell}
 $\text{\$}$ scons

include/mitsuba/core/util.h

@@ -270,6 +270,21 @@ template<typename T, typename U> inline T union_cast(const U &val) {
 	return caster.t;
 }
 
+/// Return a string representation of a list of objects
+template<class T> std::string listToString(const std::vector<T> &vec) {
+	std::ostringstream oss;
+	oss << "{" << endl;
+	for (size_t i=0; i<vec.size(); ++i) {
+		oss << "  " << indent(vec[i]->toString());
+		if (i != vec.size()-1)
+			oss << "," << endl;
+		else
+			oss << endl;
+	}
+	oss << "}";
+	return oss.str();
+}
+
 MTS_NAMESPACE_END
 
 #endif /* __UTIL_H */

src/libcore/bitmap.cpp

@@ -356,7 +356,7 @@ void Bitmap::loadPNG(Stream *stream) {
 	}
 
 	/* Error handling */
-	if (setjmp(png_ptr->jmpbuf)) {
+	if (setjmp(png_jmpbuf(png_ptr))) {
 		png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) NULL);
 		if (rows)
 			delete[] rows;
@@ -379,7 +379,8 @@ void Bitmap::loadPNG(Stream *stream) {
 		png_set_expand(png_ptr); // expand indexed files
 		newDepth = 8;
 	} else if (colortype == PNG_COLOR_TYPE_GRAY && bitdepth < 8) {
-		png_set_gray_1_2_4_to_8(png_ptr); // convert grayscale to 8bit
+
+		png_set_expand_gray_1_2_4_to_8(png_ptr); // convert grayscale to 8bit
 		newDepth = 8;
 	} else if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
 		png_set_expand(png_ptr); // transparency
@@ -590,7 +591,7 @@ void Bitmap::savePNG(Stream *stream) const {
 	}
 
 	/* Error handling */
-	if (setjmp(png_ptr->jmpbuf)) {
+	if (setjmp(png_jmpbuf(png_ptr))) {
 		png_destroy_write_struct(&png_ptr, &info_ptr);
 		Log(EError, "Error writing the PNG file");
 	}

src/libcore/fresolver.cpp

@@ -14,7 +14,7 @@ FileResolver::FileResolver() {
 	addPath(MTS_RESOURCE_DIR);
 #elif defined(__OSX__)
 	MTS_AUTORELEASE_BEGIN()
-	Thread::getThread()->getFileResolver()->addPath(__ubi_bundlepath());
+	addPath(__ubi_bundlepath());
 	MTS_AUTORELEASE_END() 
 #elif defined(WIN32)
 	char lpFilename[1024];

src/libcore/thread.cpp

@@ -238,6 +238,10 @@ std::string Thread::toString() const {
 }
 
 void Thread::staticInitialization() {
+#if defined(__OSX__)
+	__ubi_autorelease_init();
+#endif
+
 	m_self = new ThreadLocal<Thread>();
 #if defined(__LINUX__) || defined(__OSX__)
 	m_idMutex = new Mutex();
@@ -252,7 +256,6 @@ void Thread::staticInitialization() {
 	m_self->set(mainThread);
 #if defined(__OSX__)
 	mainThread->m_id = 0;
-	__ubi_autorelease_init();
 #elif defined(__LINUX__)
 	m_id = 0;
 #endif

src/libhw/glrenderer.cpp

@@ -359,8 +359,6 @@ void GLRenderer::endDrawingMeshes() {
 }
 	
 void GLRenderer::drawAll() {
-	if (true)
-		return;
 	GLRenderer::beginDrawingMeshes(true);
 	std::map<const TriMesh *, GPUGeometry *>::iterator it;
 	if (m_capabilities->isSupported(RendererCapabilities::EBindless)) {

src/librender/scene.cpp

@@ -620,20 +620,6 @@ void Scene::serialize(Stream *stream, InstanceManager *manager) const {
 		manager->serialize(stream, m_netObjects[i]);
 }
 
-template<class T> std::string listToString(const std::vector<T> &vec) {
-	std::ostringstream oss;
-	oss << "{" << endl;
-	for (size_t i=0; i<vec.size(); ++i) {
-		oss << "  " << indent(vec[i]->toString());
-		if (i != vec.size()-1)
-			oss << "," << endl;
-		else
-			oss << endl;
-	}
-	oss << "}";
-	return oss.str();
-}
-
 std::string Scene::toString() const {
 	std::ostringstream oss;
 

src/medium/flake.cpp

@@ -332,29 +332,42 @@ public:
 		Log(EInfo, "                 eigs(M) = %s", vecToString(eigs).c_str());
 		Log(EInfo, "                       P = %s", mtxToString(m_P).c_str());
 #endif
+		m_kdTree = new KDTree();
 	}
 
 	FlakeMedium(Stream *stream, InstanceManager *manager)
 		: Medium(stream, manager) {
-		m_shape = static_cast<Shape *>(manager->getInstance(stream));
 		m_kdTree = new KDTree();
-		m_kdTree->addShape(m_shape.get());
-		m_kdTree->build();
-		
+		size_t shapeCount = stream->readUInt();
+		for (size_t i=0; i<shapeCount; ++i) 
+			addChild("", static_cast<Shape *>(manager->getInstance(stream)));
 		m_D = SHVector(stream);
 		m_sigmaS = SHVector(stream);
 		m_sigmaT = SHVector(stream);
 		m_area = stream->readFloat();
 		m_rho = stream->readFloat();
 		m_frame = Frame(stream);
+		configure();
 	}
 
 	virtual ~FlakeMedium() {
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			m_shapes[i]->decRef();
+	}
+
+	void configure() {
+		Medium::configure();
+		if (m_shapes.size() == 0)
+			Log(EError, "This medium requires one or more Shape instance as a child");
+		m_kdTree->build();
+		m_aabb = m_kdTree->getAABB();
 	}
 
 	void serialize(Stream *stream, InstanceManager *manager) const {
 		Medium::serialize(stream, manager);
-		manager->serialize(stream, m_shape.get());
+		stream->writeUInt((uint32_t) m_shapes.size());
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			manager->serialize(stream, m_shapes[i]);
 		m_D.serialize(stream);
 		m_sigmaS.serialize(stream);
 		m_sigmaT.serialize(stream);
@@ -478,17 +491,25 @@ public:
 
 	void setParent(ConfigurableObject *parent) {
 		if (parent->getClass()->derivesFrom(Shape::m_theClass))
-			Log(EError, "Medium shape cannot be part of the scene");
+			Log(EError, "Medium cannot be a parent of a shape");
 	}
 
 	void addChild(const std::string &name, ConfigurableObject *child) {
 		if (child->getClass()->derivesFrom(Shape::m_theClass)) {
-			Assert(m_shape == NULL);
-			m_shape = static_cast<Shape *>(child);
-			m_kdTree = new KDTree();
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
-			m_aabb = m_kdTree->getAABB();
+			Shape *shape = static_cast<Shape *>(child);
+			if (shape->isCompound()) {
+				int ctr = 0;
+				while (true) {
+					ref<Shape> childShape = shape->getElement(ctr++);
+					if (!childShape)
+						break;
+					addChild("", childShape);
+				}
+			} else {
+				m_kdTree->addShape(shape);
+				shape->incRef();
+				m_shapes.push_back(shape);
+			}
 		} else {
 			Medium::addChild(name, child);
 		}
@@ -499,15 +520,15 @@ public:
 		oss << "FlakeMedium[" << endl
 			<< "  area = " << m_area << "," << std::endl
 			<< "  rho = " << m_rho << "," << std::endl
-			<< "  shape = " << indent(m_shape->toString()) << std::endl
+			<< "  shapes = " << indent(listToString(m_shapes)) << std::endl
 			<< "]";
 		return oss.str();
 	}
 	
 	MTS_DECLARE_CLASS()
 private:
-	ref<Shape> m_shape;
 	ref<KDTree> m_kdTree;
+	std::vector<Shape *> m_shapes;
 	SHVector m_D, m_sigmaS, m_sigmaT;
 	Float m_area, m_rho;
 	Frame m_frame;

src/medium/heterogeneous-flake.cpp

@@ -203,12 +203,16 @@ public:
 		m_sigmaT.convolve(absCos);
 		m_sigmaT *= 2;
 		Assert(m_sigmaT.isAzimuthallyInvariant());
+		m_kdTree = new KDTree();
 	}
 
 	/* Unserialize from a binary data stream */
 	HeterogeneousFlakeMedium(Stream *stream, InstanceManager *manager) 
 		: Medium(stream, manager) {
-		m_shape = static_cast<Shape *>(manager->getInstance(stream));
+		m_kdTree = new KDTree();
+		size_t shapeCount = stream->readUInt();
+		for (size_t i=0; i<shapeCount; ++i) 
+			addChild("", static_cast<Shape *>(manager->getInstance(stream)));
 		m_densities = static_cast<VolumeDataSource *>(manager->getInstance(stream));
 		m_albedo = static_cast<VolumeDataSource *>(manager->getInstance(stream));
 		m_orientations = static_cast<VolumeDataSource *>(manager->getInstance(stream));
@@ -220,21 +224,20 @@ public:
 		m_sigmaT = SHVector(stream);
 		m_phaseExpansion = SHVector4D(stream);
 		m_samplingRecursions = stream->readInt();
-		m_kdTree = new KDTree();
-		if (m_shape != NULL) {
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
-		}
 		configure();
 	}
 
 	virtual ~HeterogeneousFlakeMedium() {
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			m_shapes[i]->decRef();
 	}
 
 	/* Serialize the volume to a binary data stream */
 	void serialize(Stream *stream, InstanceManager *manager) const {
 		Medium::serialize(stream, manager);
-		manager->serialize(stream, m_shape.get());
+		stream->writeUInt((uint32_t) m_shapes.size());
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			manager->serialize(stream, m_shapes[i]);
 		manager->serialize(stream, m_densities.get());
 		manager->serialize(stream, m_albedo.get());
 		manager->serialize(stream, m_orientations.get());
@@ -270,19 +273,36 @@ public:
 		m_phaseFunction = new FlakePhaseFunction(m_sigmaT, m_samplingRecursions,
 			&m_phaseExpansion, m_exponent, m_normalization, m_fiber, this);
 
-		if (m_shape != NULL)
+		if (m_shapes.size() > 0) {
+			m_kdTree->build();
 			m_aabb = m_kdTree->getAABB();
-		else
+		} else {
 			m_aabb = m_densities->getAABB();
 		}
+	}
+
+	void setParent(ConfigurableObject *parent) {
+		if (parent->getClass()->derivesFrom(Shape::m_theClass))
+			Log(EError, "Medium cannot be a parent of a shape");
+	}
+
 
 	void addChild(const std::string &name, ConfigurableObject *child) {
 		if (child->getClass()->derivesFrom(Shape::m_theClass)) {
-			Assert(m_shape == NULL);
-			m_shape = static_cast<Shape *>(child);
-			m_kdTree = new KDTree();
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
+			Shape *shape = static_cast<Shape *>(child);
+			if (shape->isCompound()) {
+				int ctr = 0;
+				while (true) {
+					ref<Shape> childShape = shape->getElement(ctr++);
+					if (!childShape)
+						break;
+					addChild("", childShape);
+				}
+			} else {
+				m_kdTree->addShape(shape);
+				shape->incRef();
+				m_shapes.push_back(shape);
+			}
 		} else if (child->getClass()->derivesFrom(VolumeDataSource::m_theClass)) {
 			VolumeDataSource *volume = static_cast<VolumeDataSource *>(child);
 
@@ -302,7 +322,7 @@ public:
 	}
 
 	Float distanceToMediumEntry(const Ray &ray) const {
-		if (m_shape != NULL) {
+		if (m_shapes.size() != 0) {
 			Ray r(ray, Epsilon, std::numeric_limits<Float>::infinity());
 			Intersection its;
 			if (!m_kdTree->rayIntersect(r, its)) 
@@ -320,7 +340,7 @@ public:
 	}
 
 	Float distanceToMediumExit(const Ray &ray) const {
-		if (m_shape != NULL) {
+		if (m_shapes.size() != 0) {
 			Ray r(ray, Epsilon, std::numeric_limits<Float>::infinity());
 			Intersection its;
 			if (!m_kdTree->rayIntersect(r, its)) 
@@ -528,10 +548,10 @@ public:
 	std::string toString() const {
 		std::ostringstream oss;
 		oss << "HeterogeneousFlakeMedium[" << endl
-			<< "  albedo=" << indent(m_albedo.toString()) << endl
-			<< "  orientations=" << indent(m_orientations.toString()) << endl
-			<< "  densities=" << indent(m_densities.toString()) << endl
-			<< "  shape =" << indent(m_shape.toString()) << endl
+			<< "  albedo=" << indent(m_albedo.toString()) << "," << endl
+			<< "  orientations=" << indent(m_orientations.toString()) << "," << endl
+			<< "  densities=" << indent(m_densities.toString()) << "," << endl
+			<< "  shapes = " << indent(listToString(m_shapes)) << endl
 			<< "]";
 		return oss.str();
 	}
@@ -540,8 +560,8 @@ private:
 	ref<VolumeDataSource> m_densities;
 	ref<VolumeDataSource> m_albedo;
 	ref<VolumeDataSource> m_orientations;
-	ref<Shape> m_shape;
 	ref<KDTree> m_kdTree;
+	std::vector<Shape *> m_shapes;
 	Float m_stepSize;
 	/* Flake model-related */
 	SHVector m_D, m_sigmaT;

src/medium/heterogeneous-stencil.cpp

@@ -34,32 +34,35 @@ class HeterogeneousStencilMedium : public Medium {
 public:
 	HeterogeneousStencilMedium(const Properties &props) 
 		: Medium(props) {
+		m_kdTree = new KDTree();
 		m_stepSize = props.getFloat("stepSize", 0);
 	}
 
 	/* Unserialize from a binary data stream */
 	HeterogeneousStencilMedium(Stream *stream, InstanceManager *manager) 
 		: Medium(stream, manager) {
-		m_shape = static_cast<Shape *>(manager->getInstance(stream));
+		m_kdTree = new KDTree();
+		size_t shapeCount = stream->readUInt();
+		for (size_t i=0; i<shapeCount; ++i) 
+			addChild("", static_cast<Shape *>(manager->getInstance(stream)));
 		m_densities = static_cast<VolumeDataSource *>(manager->getInstance(stream));
 		m_albedo = static_cast<VolumeDataSource *>(manager->getInstance(stream));
 		m_orientations = static_cast<VolumeDataSource *>(manager->getInstance(stream));
 		m_stepSize = stream->readFloat();
-		m_kdTree = new KDTree();
-		if (m_shape != NULL) {
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
-		}
 		configure();
 	}
 
 	virtual ~HeterogeneousStencilMedium() {
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			m_shapes[i]->decRef();
 	}
 
 	/* Serialize the volume to a binary data stream */
 	void serialize(Stream *stream, InstanceManager *manager) const {
 		Medium::serialize(stream, manager);
-		manager->serialize(stream, m_shape.get());
+		stream->writeUInt((uint32_t) m_shapes.size());
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			manager->serialize(stream, m_shapes[i]);
 		manager->serialize(stream, m_densities.get());
 		manager->serialize(stream, m_albedo.get());
 		manager->serialize(stream, m_orientations.get());
@@ -75,11 +78,12 @@ public:
 		if (m_orientations.get() == NULL)
 			Log(EError, "No orientations specified!");
 
-	
-		if (m_shape != NULL)
+		if (m_shapes.size() != 0) {
+			m_kdTree->build();
 			m_aabb = m_kdTree->getAABB();
-		else
+		} else {
 			m_aabb = m_densities->getAABB();
+		}
 
 		if (m_stepSize == 0) {
 			m_stepSize = std::min(std::min(
@@ -94,11 +98,20 @@ public:
 
 	void addChild(const std::string &name, ConfigurableObject *child) {
 		if (child->getClass()->derivesFrom(Shape::m_theClass)) {
-			Assert(m_shape == NULL);
-			m_shape = static_cast<Shape *>(child);
-			m_kdTree = new KDTree();
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
+			Shape *shape = static_cast<Shape *>(child);
+			if (shape->isCompound()) {
+				int ctr = 0;
+				while (true) {
+					ref<Shape> childShape = shape->getElement(ctr++);
+					if (!childShape)
+						break;
+					addChild("", childShape);
+				}
+			} else {
+				m_kdTree->addShape(shape);
+				shape->incRef();
+				m_shapes.push_back(shape);
+			}
 		} else if (child->getClass()->derivesFrom(VolumeDataSource::m_theClass)) {
 			VolumeDataSource *volume = static_cast<VolumeDataSource *>(child);
 
@@ -118,7 +131,7 @@ public:
 	}
 
 	Float distanceToMediumEntry(const Ray &ray) const {
-		if (m_shape != NULL) {
+		if (m_shapes.size() != 0) {
 			Ray r(ray, Epsilon, std::numeric_limits<Float>::infinity());
 			Intersection its;
 			if (!m_kdTree->rayIntersect(r, its)) 
@@ -136,7 +149,7 @@ public:
 	}
 
 	Float distanceToMediumExit(const Ray &ray) const {
-		if (m_shape != NULL) {
+		if (m_shapes.size() != 0) {
 			Ray r(ray, Epsilon, std::numeric_limits<Float>::infinity());
 			Intersection its;
 			if (!m_kdTree->rayIntersect(r, its)) 
@@ -322,8 +335,7 @@ public:
 		oss << "HeterogeneousStencilMedium[" << endl
 			<< "  albedo=" << indent(m_albedo.toString()) << endl
 			<< "  orientations=" << indent(m_orientations.toString()) << endl
-			<< "  densities=" << indent(m_densities.toString()) << endl
-			<< "  shape =" << indent(m_shape.toString()) << endl
+			<< "  densities=" << indent(m_densities.toString()) 
 			<< "]";
 		return oss.str();
 	}
@@ -332,8 +344,8 @@ private:
 	ref<VolumeDataSource> m_densities;
 	ref<VolumeDataSource> m_albedo;
 	ref<VolumeDataSource> m_orientations;
-	ref<Shape> m_shape;
 	ref<KDTree> m_kdTree;
+	std::vector<Shape *> m_shapes;
 	Float m_stepSize;
 };
 

src/medium/homogeneous.cpp

@@ -66,14 +66,15 @@ public:
 			coeffs[i] = m_sigmaT[i];
 
 		m_maxExpDist = new MaxExpDist(coeffs);
+		m_kdTree = new KDTree();
 	}
 
 	HomogeneousMedium(Stream *stream, InstanceManager *manager)
 		: Medium(stream, manager) {
-		m_shape = static_cast<Shape *>(manager->getInstance(stream));
 		m_kdTree = new KDTree();
-		m_kdTree->addShape(m_shape.get());
-		m_kdTree->build();
+		size_t shapeCount = stream->readUInt();
+		for (size_t i=0; i<shapeCount; ++i) 
+			addChild("", static_cast<Shape *>(manager->getInstance(stream)));
 		m_channel = stream->readInt();
 		m_strategy = (ESamplingStrategy) stream->readInt();
 		m_sigma = stream->readFloat();
@@ -82,16 +83,21 @@ public:
 		for (int i=0; i<SPECTRUM_SAMPLES; ++i)
 			coeffs[i] = m_sigmaT[i];
 
+		configure();
 		m_maxExpDist = new MaxExpDist(coeffs);
 	}
 
 	virtual ~HomogeneousMedium() {
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			m_shapes[i]->decRef();
 		delete m_maxExpDist;
 	}
 
 	void serialize(Stream *stream, InstanceManager *manager) const {
 		Medium::serialize(stream, manager);
-		manager->serialize(stream, m_shape.get());
+		stream->writeUInt((uint32_t) m_shapes.size());
+		for (size_t i=0; i<m_shapes.size(); ++i)
+			manager->serialize(stream, m_shapes[i]);
 		stream->writeInt(m_channel);
 		stream->writeInt(m_strategy);
 		stream->writeFloat(m_sigma);
@@ -99,8 +105,10 @@ public:
 	
 	void configure() {
 		Medium::configure();
-		if (m_shape.get() == NULL)
-			Log(EError, "This medium requires a Shape instance as a child ");
+		if (m_shapes.size() == 0)
+			Log(EError, "This medium requires one or more Shape instance as a child");
+		m_kdTree->build();
+		m_aabb = m_kdTree->getAABB();
 	}
 
 	bool isInside(const Ray &r) const {
@@ -267,17 +275,25 @@ public:
 
 	void setParent(ConfigurableObject *parent) {
 		if (parent->getClass()->derivesFrom(Shape::m_theClass))
-			Log(EError, "Medium shape cannot be part of the scene");
+			Log(EError, "Medium cannot be a parent of a shape");
 	}
 
 	void addChild(const std::string &name, ConfigurableObject *child) {
 		if (child->getClass()->derivesFrom(Shape::m_theClass)) {
-			Assert(m_shape == NULL);
-			m_shape = static_cast<Shape *>(child);
-			m_kdTree = new KDTree();
-			m_kdTree->addShape(m_shape.get());
-			m_kdTree->build();
-			m_aabb = m_kdTree->getAABB();
+			Shape *shape = static_cast<Shape *>(child);
+			if (shape->isCompound()) {
+				int ctr = 0;
+				while (true) {
+					ref<Shape> childShape = shape->getElement(ctr++);
+					if (!childShape)
+						break;
+					addChild("", childShape);
+				}
+			} else {
+				m_kdTree->addShape(shape);
+				shape->incRef();
+				m_shapes.push_back(shape);
+			}
 		} else {
 			Medium::addChild(name, child);
 		}
@@ -290,15 +306,15 @@ public:
 			<< "  sigmaS = " << m_sigmaS.toString() << "," << std::endl
 			<< "  sigmaT = " << m_sigmaT.toString() << "," << std::endl
 			<< "  phase = " << indent(m_phaseFunction->toString()) << "," << std::endl 
-			<< "  shape = " << indent(m_shape->toString()) << std::endl
+			<< "  shapes = " << indent(listToString(m_shapes)) << std::endl
 			<< "]";
 		return oss.str();
 	}
 
 	MTS_DECLARE_CLASS()
 private:
-	ref<Shape> m_shape;
 	ref<KDTree> m_kdTree;
+	std::vector<Shape *> m_shapes;
 	int m_channel;
 	Float m_sigma;
 	ESamplingStrategy m_strategy;

src/qtgui/importdlg.cpp

@@ -54,7 +54,8 @@ void ImportDialog::changeEvent(QEvent *e) {
 
 void ImportDialog::on_inputBrowse_clicked(bool checked) {
 	QFileDialog dialog(this);
-	dialog.setNameFilter(tr("COLLADA 1.4 scenes (*.dae *.zae);; Wavefront OBJ scenes (*.obj)"));
+	dialog.setNameFilter(tr("All supported formats (*.dae *.zae *.obj);;"
+		"COLLADA 1.4 scenes (*.dae *.zae);; Wavefront OBJ scenes (*.obj)"));
 	dialog.setAcceptMode(QFileDialog::AcceptOpen);
 	dialog.setViewMode(QFileDialog::Detail);
 	dialog.setWindowModality(Qt::ApplicationModal);

src/qtgui/mainwindow.cpp

@@ -225,7 +225,7 @@ MainWindow::MainWindow(QWidget *parent) :
 	/* Submit crash reports on OSX */
 	QDir crashDir = QDir::home();
 	crashDir.cd("Library/Logs/CrashReporter");
-	QFileInfoList crashReports = crashDir.entryInfoList(QStringList("qtgui_*"), 
+	QFileInfoList crashReports = crashDir.entryInfoList(QStringList("mtsgui_*"), 
 			QDir::Files, QDir::Name);
 
 	if (crashReports.size() > 0) {
@@ -292,6 +292,15 @@ MainWindow::MainWindow(QWidget *parent) :
 				QMessageBox::information(this, tr("Crash reporter"),
 					tr("All crash reports have been submitted. Thank you!"),
 					QMessageBox::Ok);
+		} else {
+			for (int i=0; i<crashReports.size(); ++i) {
+				QFile file(crashReports[i].absoluteFilePath());
+				if (!file.remove()) {
+					QMessageBox::critical(this, tr("Unable to submitted crash report"),
+						tr("Unable to delete a crash report -- please check the file permissions in ~/Library/Logs/CrashReporter."), QMessageBox::Ok);
+					break;
+				}
+			}
 		}
 	}
 #endif
@@ -534,7 +543,8 @@ void MainWindow::onProgressMessage(const RenderJob *job, const QString &name,
 
 void MainWindow::on_actionOpen_triggered() {
 	QFileDialog *dialog = new QFileDialog(this, Qt::Sheet);
-	dialog->setNameFilter(tr("Mitsuba scenes (*.xml);;EXR images (*.exr)"));
+	dialog->setNameFilter(tr("All supported formats (*.xml *.exr);;"
+			"Mitsuba scenes (*.xml);;EXR images (*.exr)"));
 	dialog->setAttribute(Qt::WA_DeleteOnClose);
 	dialog->setAcceptMode(QFileDialog::AcceptOpen);
 	dialog->setViewMode(QFileDialog::Detail);
@@ -1208,7 +1218,8 @@ inline float toSRGB(float value) {
 void MainWindow::on_actionExportImage_triggered() {
 	SceneContext *ctx = m_context[ui->tabBar->currentIndex()];
 	QFileDialog dialog(this, tr("Export image .."),
-		"", tr("Linear EXR Image (*.exr);; Tonemapped 8-bit PNG Image (*.png)"));
+		"", tr("All supported formats (*.exr *.png);;Linear EXR Image (*.exr)"
+			";; Tonemapped 8-bit PNG Image (*.png)"));
 
 	QSettings settings("mitsuba-renderer.org", "qtgui");
 	dialog.setViewMode(QFileDialog::Detail);