bugfixes

doc/acknowledgements.tex

@@ -11,6 +11,7 @@ Mitsuba makes heavy use of the following amazing libraries and tools:
 \item Qt 4 by Nokia
 \item OpenEXR by Industrial Light \& Magic
 \item Xerces-C+\!+ by the Apache Foundation
+\item Eigen by Beno\^it Jacob and Ga\"el Guennebaud
 \item The Boost C+\!+ class library
 \item GLEW by Milan Ikits, Marcelo E. Magallon and Lev Povalahev
 \item Mersenne Twister by Makoto Matsumoto and Takuji Nishimura

include/mitsuba/hw/gizmo.h

@@ -42,9 +42,12 @@ public:
 
 	/// Check whether the gizmo is currently active
 	inline bool isActive() const { return m_active; }
-	
+
+	/// Check whether the drag starting point has been set
+	inline bool canDrag() const { return m_drag; }
+
 	/// Check whether the gizmo is currently used in a drag operation
-	inline bool isDragging() const { return m_drag; }
+	inline bool isDragging() const { return m_drag && (m_dragStart != m_dragEnd); }
 
 	/// Check whether a certain ray intersects the gizmo
 	inline void rayIntersect(const Ray &ray, Float &t) const {
@@ -69,7 +72,7 @@ public:
 	inline void reset() { m_active = m_drag = false; }
 	
 	/// Stop dragging
-	inline void stopDrag() { m_drag = false; }
+	inline void stopDrag() { m_dragStart = m_dragEnd; }
 
 	/// Return the bounding sphere associated with the gizmo
 	inline const BSphere &getBSphere() const { return m_bsphere; }

src/libhw/gizmo.cpp

@@ -42,7 +42,6 @@ Transform Gizmo::getTransform() const {
 }
 
 void Gizmo::startDrag(const Ray &ray) {
-	m_drag = false;
 	Float nearT, farT;
 	if (!m_bsphere.rayIntersect(ray, nearT, farT)
 		|| (nearT < 0 && farT < 0)) {
@@ -53,8 +52,8 @@ void Gizmo::startDrag(const Ray &ray) {
 	} else {
 		m_dragStart = ray(nearT);
 	}
-
-	m_active = true;
+	m_dragEnd = m_dragStart;
+	m_drag = true;
 }
 
 void Gizmo::dragTo(const Ray &ray, const Camera *camera) {
@@ -71,7 +70,6 @@ void Gizmo::dragTo(const Ray &ray, const Camera *camera) {
 		m_dragEnd = m_bsphere.center + normalize(closest - 
 				m_bsphere.center) * m_bsphere.radius;
 	}
-	m_drag = true;
 }
 
 void Gizmo::draw(Renderer *renderer, const Camera *camera) {
@@ -86,10 +84,12 @@ void Gizmo::draw(Renderer *renderer, const Camera *camera) {
 	Float tcRadius = std::sqrt(length*length - radius*radius)*radius/length;
 	Float tcDist = std::sqrt(radius*radius - tcRadius*tcRadius);
 
+	renderer->setDepthTest(false);
 	renderer->drawCircle(m_bsphere.center - camToSphere * tcDist, 
 			camToSphere, tcRadius);
+	renderer->setDepthTest(true);
 
-	if (m_drag) {
+	if (m_drag && m_dragStart != m_dragEnd) {
 		Spectrum color1, color2;
 		color1.fromLinearRGB(0.7f, 0.7f, 1.0f);
 		color2.fromLinearRGB(0.3f, 0.3f, 0.3f);

src/libhw/glrenderer.cpp

@@ -39,11 +39,9 @@ GLEWContextStruct *glewGetContext() {
 MTS_NAMESPACE_BEGIN
 
 GLRenderer::GLRenderer(Session *session)
- : Renderer(session) {
-}
+ : Renderer(session) { }
 
-GLRenderer::~GLRenderer() {
-}
+GLRenderer::~GLRenderer() { }
 
 void GLRenderer::init(Device *device, Renderer *other) {
 	Renderer::init(device, other);

src/libhw/gltexture.cpp

@@ -216,7 +216,7 @@ void GLTexture::init() {
 				Log(EError, "FBO Error: Unknown error status (0x%x)!", status);
 		}
 	
-		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, GL_NONE);
 	}
 }
 
@@ -478,7 +478,7 @@ Spectrum GLTexture::getPixel(int x, int y) const {
 	glViewport(0, 0, m_size.x, m_size.y);
 	glReadPixels(x, y, 1, 1, GL_RGB, GL_FLOAT, &pixels);
 	glPopAttrib();
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, GL_NONE);
 
 	result.fromLinearRGB(pixels[0], pixels[1], pixels[2]);
 	return result;
@@ -488,7 +488,6 @@ Spectrum GLTexture::getPixel(int x, int y) const {
 void GLTexture::activateTarget() {
 	Assert(m_fbType != ENone);
 	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fboId);
-
 	glPushAttrib(GL_VIEWPORT_BIT);
 	glViewport(0, 0, m_size.x, m_size.y);
 }
@@ -525,7 +524,7 @@ void GLTexture::setTargetRegion(const Point2i &offset, const Vector2i &size) {
 void GLTexture::releaseTarget() {
 	Assert(m_fbType != ENone);
 	glPopAttrib();
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, GL_NONE);
 	if (isMipMapped())
 		m_needsUpdate = true;
 }
@@ -541,10 +540,11 @@ void GLTexture::bind(int textureUnit, int textureIndex) const {
 	}
 
 	glEnable(m_glType);
-	if (textureIndex == 1 && m_fbType == EColorAndDepthBuffer) 
+	if (textureIndex == 1 && m_fbType == EColorAndDepthBuffer) {
 		glBindTexture(m_glType, m_depthId);
-	else 
+	} else {
 		glBindTexture(m_glType, m_id);
+	}
 
 	if (isMipMapped() && m_needsUpdate) {
 		glGenerateMipmapEXT(m_glType);
@@ -616,9 +616,9 @@ void GLTexture::blit(GPUTexture *target, int what) const {
 	glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, GL_NONE);
 }
 
-void GLTexture::blit(GPUTexture *target, int what, const Point2i &sourceOffset,
-	const Vector2i &sourceSize, const Point2i &destOffset,
-	const Vector2i &destSize) const {
+void GLTexture::blit(GPUTexture *target, int what, 
+		const Point2i &sourceOffset, const Vector2i &sourceSize,
+		const Point2i &destOffset, const Vector2i &destSize) const {
 	GLTexture *dest = static_cast<GLTexture *>(target);
 	Assert(m_fbType != ENone && (dest == NULL || dest->m_fbType != ENone));
 

src/librender/preview.cpp

@@ -265,7 +265,7 @@ void PreviewWorker::processCoherent(const WorkUnit *workUnit, WorkResult *workRe
 			secRay4.dRcp[0].ps = _mm_div_ps(SSEConstants::one.ps, secRay4.d[0].ps);
 			secRay4.dRcp[1].ps = _mm_div_ps(SSEConstants::one.ps, secRay4.d[1].ps);
 			secRay4.dRcp[2].ps = _mm_div_ps(SSEConstants::one.ps, secRay4.d[2].ps);
-			
+
 			cosThetaLight.ps = _mm_sub_ps(_mm_setzero_ps(),
 				_mm_add_ps(_mm_add_ps(
 					_mm_mul_ps(nSecD[0].ps, lumDir[0]),
@@ -291,6 +291,12 @@ void PreviewWorker::processCoherent(const WorkUnit *workUnit, WorkResult *workRe
 				const Shape *shape = (*m_shapes)[its4.shapeIndex.i[idx]];
 				const BSDF *bsdf = shape->getBSDF();
 
+				if (EXPECT_NOT_TAKEN(!bsdf)) {
+					memset(&emitted[idx], 0, sizeof(Spectrum));
+					memset(&direct[idx], 0, sizeof(Spectrum));
+					continue;
+				}
+
 				if (EXPECT_TAKEN(primIndex != KNoTriangleFlag)) {
 					const TriMesh *mesh = static_cast<const TriMesh *>(shape);
 					const Triangle &t = mesh->getTriangles()[primIndex];

src/qtgui/acknowledgmentdlg.ui

@@ -58,6 +58,7 @@ p, li { white-space: pre-wrap; }
 <ul style="-qt-list-indent: 1;"><li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://qt.nokia.com/products"><span style=" text-decoration: underline; color:#0000ff;">Qt 4</span></a> by Nokia</li>
 <li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://www.openexr.com/"><span style=" text-decoration: underline; color:#0000ff;">OpenEXR</span></a> by Industrial Light & Magic</li>
 <li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://xerces.apache.org/xerces-c/"><span style=" text-decoration: underline; color:#0000ff;">Xerces-C++</span></a> by the Apache Foundation</li>
+<li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://eigen.tuxfamily.org"><span style=" text-decoration: underline; color:#0000ff;">Eigen</span></a> by Benoît Jacob and Gaël Guennebaud</li>
 <li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;">The <a href="http://www.boost.org/"><span style=" text-decoration: underline; color:#0000ff;">Boost</span></a> C++ class library</li>
 <li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://glew.sourceforge.net/"><span style=" text-decoration: underline; color:#0000ff;">GLEW</span></a> by Milan Ikits, Marcelo E. Magallon and Lev Povalahev</li>
 <li style=" margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;"><a href="http://sourceforge.net/projects/collada-dom/"><span style=" text-decoration: underline; color:#0000ff;">COLLADA DOM</span></a> by Sony Computer Entertainment</li>

src/qtgui/glwidget.cpp

@@ -68,6 +68,10 @@ GLWidget::GLWidget(QWidget *parent) :
 }
 
 GLWidget::~GLWidget() {
+	shutdown();
+}
+
+void GLWidget::shutdown() {
 	if (m_preview)
 		m_preview->quit();
 }
@@ -157,9 +161,9 @@ void GLWidget::initializeGL() {
 
 		m_gammaTonemap->setSource(GPUProgram::EFragmentProgram,
 			"#version 120\n"
-			"uniform sampler2D source;\n"
+			"uniform sampler2D colorSource, depthSource;\n"
 			"uniform float invWhitePoint, invGamma;\n"
-			"uniform bool sRGB;\n"
+			"uniform bool sRGB, hasDepth;\n"
 			"\n"
 			"float toSRGB(float value) {\n"
 			"	if (value < 0.0031308)\n"
@@ -168,11 +172,12 @@ void GLWidget::initializeGL() {
 			"}\n"
 			"\n"
 			"void main() {\n"
-			"	vec4 color = texture2D(source, gl_TexCoord[0].xy) * invWhitePoint;\n"
+			"	vec4 color = texture2D(colorSource, gl_TexCoord[0].xy) * invWhitePoint;\n"
 			"	if (sRGB)\n"
 			"		gl_FragColor = vec4(toSRGB(color.r), toSRGB(color.g), toSRGB(color.b), 1);\n"
 			"	else\n"
 			"		gl_FragColor = vec4(pow(color.rgb, vec3(invGamma)), 1);\n"
+			"	gl_FragDepth = hasDepth ? texture2D(depthSource, gl_TexCoord[0].xy).r : 0.5;\n"
 			"}\n"
 		);
 
@@ -185,9 +190,9 @@ void GLWidget::initializeGL() {
 
 		m_reinhardTonemap->setSource(GPUProgram::EFragmentProgram,
 			"#version 120\n"
-			"uniform sampler2D source;\n"
+			"uniform sampler2D colorSource, depthSource;\n"
 			"uniform float key, invWpSqr, invGamma, multiplier;\n"
-			"uniform bool sRGB;\n"
+			"uniform bool sRGB, hasDepth;\n"
 			"\n"
 			"float toSRGB(float value) {\n"
 			"	if (value < 0.0031308)\n"
@@ -204,7 +209,7 @@ void GLWidget::initializeGL() {
 			"                            -0.969256,  1.875991,  0.041556,\n"
 			"					          0.055648, -0.204043,  1.057311);\n"
 			"\n"
-			"	vec4 color = texture2D(source, gl_TexCoord[0].xy)*multiplier;\n"
+			"	vec4 color = texture2D(colorSource, gl_TexCoord[0].xy)*multiplier;\n"
 			"   vec3 xyz = rgb2xyz * color.rgb;\n"
 			"   float normalization = 1.0/(xyz.x + xyz.y + xyz.z);\n"
 			"   vec3 Yxy = vec3(xyz.x*normalization, xyz.y*normalization, xyz.y);\n"
@@ -216,6 +221,7 @@ void GLWidget::initializeGL() {
 			"		gl_FragColor = vec4(toSRGB(color.r), toSRGB(color.g), toSRGB(color.b), 1);\n"
 			"	else\n"
 			"		gl_FragColor = vec4(pow(color.rgb, vec3(invGamma)), 1);\n"
+			"	gl_FragDepth = hasDepth ? texture2D(depthSource, gl_TexCoord[0].xy).r : 0.5;\n"
 			"}\n"
 		);
 
@@ -573,15 +579,14 @@ void GLWidget::keyPressEvent(QKeyEvent *event) {
 		case Qt::Key_Down:
 			m_downKeyDown = true; break;
 		case Qt::Key_A: {
-			if (m_context->selectionMode == ENothing) {
-				m_context->selectionMode = EScene;
-				m_gizmo->init(m_context->scene->getBSphere());
-			} else {
+			if (m_context->selectionMode == EScene) {
 				m_context->selectionMode = ENothing;
 				m_gizmo->reset();
+			} else {
+				m_context->selectionMode = EScene;
+				m_gizmo->init(m_context->scene->getBSphere());
 			}
 			m_context->selectedShape = NULL;
-			updateGL();
 		}
 		// break intentionally missing
 		case Qt::Key_F: {
@@ -653,7 +658,7 @@ void GLWidget::mouseMoveEvent(QMouseEvent *event) {
 	bool didMove = false;
 	
 	if (m_navigationMode == EArcBall) {
-		if (event->buttons() & Qt::LeftButton) {
+		if (event->buttons() & Qt::LeftButton && m_gizmo->canDrag()) {
 			Ray ray;
 			Point2i offset = upperLeft();
 			Point2 sample = Point2(m_mousePos.x() - offset.x, m_mousePos.y() - offset.y);
@@ -811,8 +816,12 @@ void GLWidget::mousePressEvent(QMouseEvent *event) {
 			if (its.t < t) {
 				SLog(EInfo, "Selected shape \"%s\"", its.shape->getName().c_str());
 				m_context->selectedShape = its.shape;
-				m_gizmo->init(its.shape->getAABB().getBSphere());
+				BSphere bsphere = its.shape->getAABB().getBSphere();
+				bool newSelection = (bsphere != m_gizmo->getBSphere());
+				m_gizmo->init(bsphere);
 				m_context->selectionMode = EShape;
+				if (newSelection) 
+					return;
 			}
 		} else {
 			if (t == std::numeric_limits<Float>::infinity()) {
@@ -822,7 +831,7 @@ void GLWidget::mousePressEvent(QMouseEvent *event) {
 				return;
 			}
 		}
-		
+
 		m_gizmo->startDrag(ray);
 		m_storedViewTransform = camera->getViewTransform();
 	}
@@ -856,7 +865,8 @@ void GLWidget::mouseReleaseEvent(QMouseEvent *event) {
 }
 
 void GLWidget::paintGL() {
-	m_renderer->setDepthTest(false);
+	m_renderer->setDepthTest(true);
+	m_renderer->setDepthMask(true);
 	if (m_context == NULL) {
 		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 		m_renderer->clear();
@@ -866,7 +876,7 @@ void GLWidget::paintGL() {
 	} else if (m_context != NULL) {
 		Vector2i size;
 		glClearColor(0.2f, 0.2f, 0.2f, 1.0f);
-		glClear(GL_COLOR_BUFFER_BIT);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 		PreviewQueueEntry entry;
 		GPUTexture *buffer = NULL;
 
@@ -933,7 +943,12 @@ void GLWidget::paintGL() {
 
 			size = Vector2i(m_framebuffer->getSize().x, m_framebuffer->getSize().y);
 			buffer = m_framebuffer;
+		} else {
+			return;
 		}
+		bool hasDepth = m_context->mode == EPreview
+			&& (m_context->previewMethod == EOpenGL ||
+				m_context->previewMethod == EOpenGLSinglePass);
 
 		if (m_softwareFallback) {
 			buffer->bind();
@@ -947,11 +962,15 @@ void GLWidget::paintGL() {
 			if (m_context->mode == EPreview)
 				invWhitePoint /= entry.vplSampleOffset;
 
+			if (hasDepth)
+				buffer->bind(1, 1);
 			m_gammaTonemap->bind();
-			m_gammaTonemap->setParameter("source", 0);
+			m_gammaTonemap->setParameter("colorSource", 0);
+			m_gammaTonemap->setParameter("depthSource", 1);
 			m_gammaTonemap->setParameter("invWhitePoint", invWhitePoint);
 			m_gammaTonemap->setParameter("invGamma", 1/m_context->gamma);
 			m_gammaTonemap->setParameter("sRGB", m_context->srgb);
+			m_gammaTonemap->setParameter("hasDepth", hasDepth);
 			m_renderer->blitTexture(buffer, m_context->mode == EPreview, 
 				!m_hScroll->isVisible(), !m_vScroll->isVisible(),
 				-m_context->scrollOffset);
@@ -1015,13 +1034,17 @@ void GLWidget::paintGL() {
 				logLuminance = 1;
 			}
 
+			if (hasDepth)
+				buffer->bind(1, 1);
 			m_reinhardTonemap->bind();
-			m_reinhardTonemap->setParameter("source", 0);
+			m_reinhardTonemap->setParameter("colorSource", 0);
+			m_reinhardTonemap->setParameter("depthSource", 1);
 			m_reinhardTonemap->setParameter("key", m_context->reinhardKey/logLuminance);
 			m_reinhardTonemap->setParameter("multiplier", multiplier);
 			m_reinhardTonemap->setParameter("invWpSqr", std::pow((Float) 2, m_context->reinhardBurn));
 			m_reinhardTonemap->setParameter("invGamma", 1/m_context->gamma);
 			m_reinhardTonemap->setParameter("sRGB", m_context->srgb);
+			m_reinhardTonemap->setParameter("hasDepth", hasDepth);
 			m_renderer->blitTexture(buffer, m_context->mode == EPreview, 
 				!m_hScroll->isVisible(), !m_vScroll->isVisible(),
 				-m_context->scrollOffset);
@@ -1059,19 +1082,14 @@ void GLWidget::paintGL() {
 		if (m_context->mode == EPreview) {
 			const ProjectiveCamera *camera = static_cast<const ProjectiveCamera *>
 				(m_context->scene->getCamera());
-			m_renderer->setCamera(camera);
-			
-			Point2i offset = upperLeft(true);
-
-			buffer->blit(NULL, GPUTexture::EDepthBuffer, Point2i(0, 0),
-				size, offset, size);
 			glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
-
+			m_renderer->setCamera(camera);
+			glPushAttrib(GL_VIEWPORT_BIT);
+			Point2i offset = upperLeft(true);
 			glViewport(offset.x, offset.y, size.x, size.y);
-			m_renderer->setDepthTest(true);
 			m_renderer->setDepthMask(false);
+			m_renderer->setDepthTest(true);
 			m_renderer->setBlendMode(Renderer::EBlendAdditive);
-			glDepthFunc(GL_LESS);
 
 			if (m_context->showKDTree) {
 				oglRenderKDTree(m_context->scene->getKDTree());
@@ -1085,9 +1103,7 @@ void GLWidget::paintGL() {
 				m_gizmo->draw(m_renderer, camera);
 
 			m_renderer->setBlendMode(Renderer::EBlendNone);
-			m_renderer->setDepthTest(false);
-			m_renderer->setDepthMask(true);
-			glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
+			glPopAttrib();
 		}
 	}
 	swapBuffers();

src/qtgui/glwidget.h

@@ -46,6 +46,7 @@ public:
 	void resumePreview();
 	void refreshScene();
 	void resetPreview();
+	void shutdown();
 	inline const RendererCapabilities *getRendererCapabilities() const {
 		return m_renderer->getCapabilities();
 	}

src/qtgui/mainwindow.cpp

@@ -21,6 +21,7 @@
 #include "rendersettingsdlg.h"
 #include "previewsettingsdlg.h"
 #include "programsettingsdlg.h"
+#include "sceneinfodlg.h"
 #include "sceneloader.h"
 #include "logwidget.h"
 #include "navdlg.h"
@@ -496,6 +497,28 @@ void MainWindow::on_actionShowKDTree_triggered() {
 		ui->glView->resetPreview();
 }
 
+void MainWindow::on_actionSceneDescription_triggered() {
+	int currentIndex = ui->tabBar->currentIndex();
+	if (currentIndex == -1)
+		return;
+	SceneContext *context= m_context[currentIndex];
+	SceneInformationDialog *dialog = new SceneInformationDialog(this,
+		context->scene);
+	QDesktopWidget *desktop = QApplication::desktop();
+	dialog->move(QPoint((desktop->width() - dialog->width()) / 2, (desktop->height() - dialog->height())/2));
+	connect(dialog, SIGNAL(finished(int)), this, SLOT(onSceneInformationClose(int)));
+	m_currentChild = dialog;
+	// prevent a tab drawing artifact on Qt/OSX
+	m_activeWindowHack = true;
+	dialog->show();
+	qApp->processEvents();
+	m_activeWindowHack = false;
+}
+
+void MainWindow::onSceneInformationClose(int reason) {
+	m_currentChild = NULL;
+}
+
 void MainWindow::changeEvent(QEvent *e) {
     QMainWindow::changeEvent(e);
     switch (e->type()) {
@@ -700,6 +723,7 @@ void MainWindow::updateUI() {
 	ui->actionAdjustSize->setEnabled(hasTab);
 	ui->actionShowKDTree->setEnabled(hasTab);
 	ui->actionShowKDTree->setChecked(hasTab && context->showKDTree);
+	ui->actionSceneDescription->setEnabled(hasTab);
 #if !defined(__OSX__)
 	ui->actionPreviewSettings->setEnabled(!fallback && hasTab);
 #else
@@ -863,6 +887,7 @@ void MainWindow::closeEvent(QCloseEvent *event) {
 			return;
 		}
 	}
+	ui->glView->shutdown();
 	QMainWindow::closeEvent(event);
 	m_logWidget->hide();
 	Logger *logger = Thread::getThread()->getLogger();
@@ -1369,7 +1394,6 @@ void MainWindow::onSaveAsDialogClose(int reason) {
 	QFileDialog *dialog = static_cast<QFileDialog *>(sender());
 	m_currentChild = NULL;
 	if (reason == QDialog::Accepted) {
-		m_currentChild = NULL;
         QString fileName = dialog->selectedFiles().value(0);
 		settings.setValue("fileDialogState", dialog->saveState());
 		saveScene(this, context, fileName);

src/qtgui/mainwindow.h

@@ -127,6 +127,7 @@ private slots:
 	void on_actionReportBug_triggered();
 	void on_actionFeedback_triggered();
 	void on_actionShowKDTree_triggered();
+	void on_actionSceneDescription_triggered();
 	void on_tabBar_currentChanged(int index);
 	bool on_tabBar_tabCloseRequested(int index);
 	void on_tabBar_tabMoved(int from, int to);
@@ -153,6 +154,7 @@ private slots:
 	void onExportDialogClose(int reason);
 	void onRenderSettingsClose(int reason);
 	void onImportDialogClose(int reason);
+	void onSceneInformationClose(int reason);
 
 private:
     Ui::MainWindow *ui;

src/qtgui/mainwindow.ui

@@ -151,6 +151,7 @@
       <string>Developer</string>
      </property>
      <addaction name="actionShowKDTree"/>
+     <addaction name="actionSceneDescription"/>
     </widget>
     <addaction name="actionUpdateCheck"/>
     <addaction name="actionStartServer"/>
@@ -467,6 +468,11 @@
     <string>Visualize kd-Tree</string>
    </property>
   </action>
+  <action name="actionSceneDescription">
+   <property name="text">
+    <string>Describe Scene..</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>

src/qtgui/preview.cpp

@@ -325,7 +325,7 @@ void PreviewThread::run() {
 				target.buffer->setFormat(GPUTexture::EFloat32RGB);
 				target.buffer->setSize(size);
 				target.buffer->setFilterType(GPUTexture::ENearest);
-				target.buffer->setFrameBufferType(GPUTexture::EColorBuffer);
+				target.buffer->setFrameBufferType(GPUTexture::EColorAndDepthBuffer);
 				target.buffer->setMipMapped(false);
 				target.buffer->init();
 				target.buffer->incRef();

src/qtgui/sceneinfodlg.cpp

@@ -0,0 +1,42 @@
+/*
+    This file is part of Mitsuba, a physically based rendering system.
+
+    Copyright (c) 2007-2010 by Wenzel Jakob and others.
+
+    Mitsuba is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License Version 3
+    as published by the Free Software Foundation.
+
+    Mitsuba is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "ui_sceneinfodlg.h"
+#include "sceneinfodlg.h"
+
+SceneInformationDialog::SceneInformationDialog(QWidget *parent, Scene *scene) :
+		QDialog(parent),
+	ui(new Ui::SceneInformationDialog) {
+	ui->setupUi(this);
+	ui->textEdit->setText(scene->toString().c_str());
+}
+
+SceneInformationDialog::~SceneInformationDialog() {
+	delete ui;
+}
+
+void SceneInformationDialog::changeEvent(QEvent *e) {
+    QDialog::changeEvent(e);
+    switch (e->type()) {
+    case QEvent::LanguageChange:
+		ui->retranslateUi(this);
+        break;
+    default:
+        break;
+    }
+}

src/qtgui/sceneinfodlg.h

@@ -0,0 +1,39 @@
+/*
+    This file is part of Mitsuba, a physically based rendering system.
+
+    Copyright (c) 2007-2010 by Wenzel Jakob and others.
+
+    Mitsuba is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License Version 3
+    as published by the Free Software Foundation.
+
+    Mitsuba is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#if !defined(__SCENEINFODLG_H)
+#define __SCENEINFODLG_H
+
+#include "common.h"
+
+namespace Ui {
+	class SceneInformationDialog;
+}
+
+class SceneInformationDialog : public QDialog {
+    Q_OBJECT
+public:
+	SceneInformationDialog(QWidget *parent, Scene *scene);
+	~SceneInformationDialog();
+protected:
+    void changeEvent(QEvent *e);
+private:
+	Ui::SceneInformationDialog *ui;
+};
+
+#endif // __SCENEINFODLG_H

src/qtgui/sceneinfodlg.ui

@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>SceneInformationDialog</class>
+ <widget class="QDialog" name="SceneInformationDialog">
+  <property name="windowModality">
+   <enum>Qt::NonModal</enum>
+  </property>
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>676</width>
+    <height>534</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Scene Information</string>
+  </property>
+  <layout class="QGridLayout" name="gridLayout">
+   <item row="1" column="0">
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>198</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <widget class="QPushButton" name="pushButton">
+       <property name="text">
+        <string>&amp;Close</string>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+   <item row="0" column="0">
+    <widget class="QTextEdit" name="textEdit">
+     <property name="font">
+      <font>
+       <family>Monospace</family>
+       <pointsize>8</pointsize>
+      </font>
+     </property>
+     <property name="html">
+      <string>&lt;!DOCTYPE HTML PUBLIC &quot;-//W3C//DTD HTML 4.0//EN&quot; &quot;http://www.w3.org/TR/REC-html40/strict.dtd&quot;&gt;
+&lt;html&gt;&lt;head&gt;&lt;meta name=&quot;qrichtext&quot; content=&quot;1&quot; /&gt;&lt;style type=&quot;text/css&quot;&gt;
+p, li { white-space: pre-wrap; }
+&lt;/style&gt;&lt;/head&gt;&lt;body style=&quot; font-family:'Monospace'; font-size:8pt; font-weight:400; font-style:normal;&quot;&gt;
+&lt;p style=&quot;-qt-paragraph-type:empty; margin-top:12px; margin-bottom:12px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; font-family:'Ubuntu'; font-size:11pt;&quot;&gt;&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>pushButton</sender>
+   <signal>clicked()</signal>
+   <receiver>SceneInformationDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>327</x>
+     <y>263</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>334</x>
+     <y>199</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>