diff --git a/examples/trace/trace_wrapper.c b/examples/trace/trace_wrapper.c
index 0e29b109..b430071b 100644
--- a/examples/trace/trace_wrapper.c
+++ b/examples/trace/trace_wrapper.c
@@ -57,6 +57,7 @@ void* data(uint64_t offset, uint64_t size) {
 }
 
 void image(const char *channel, const void *pixels, int width, int height, ANARIDataType type) {
+    printf("%d %d\n", width, height);
     static int count = 0;
     count += 1;
     char filename[100];
@@ -78,13 +79,16 @@ void trace(ANARIDevice device) {
 
 int main(int argc, char *argv[]) {
 
+    const char *lib = argc>1 ? argv[1] : "helide";
+    const char *dev = argc>2 ? argv[2] : "default";
+
     if(load_whole_file("data.bin")) {
         fprintf(stderr, "ERROR: could not open data file.\n");
         return 1;
     }
 
-    ANARILibrary library = anariLoadLibrary("example", statusFunc, NULL);
-    ANARIDevice device = anariNewDevice(library, "default");
+    ANARILibrary library = anariLoadLibrary(lib, statusFunc, NULL);
+    ANARIDevice device = anariNewDevice(library, dev);
 
     if (!device) {
         fprintf(stderr, "ERROR: could not create device\n");
diff --git a/examples/viewer/MainWindow.cpp b/examples/viewer/MainWindow.cpp
index ea45ac82..9486db89 100644
--- a/examples/viewer/MainWindow.cpp
+++ b/examples/viewer/MainWindow.cpp
@@ -29,6 +29,7 @@ static const std::vector<std::string> g_scenes = {
     "textured_cube",
     "gravity_spheres_volume",
     "attributes",
+    "random_cylinders",
     "file_obj"
     //
 };
@@ -226,7 +227,7 @@ MainWindow::MainWindow(const glm::uvec2 &windowSize)
   ImGui_ImplOpenGL3_Init();
 
   ImGuiIO &io = ImGui::GetIO();
-  io.FontGlobalScale = 1.25f;
+  io.FontGlobalScale = 1.0f;
 
   // set GLFW callbacks
   glfwSetFramebufferSizeCallback(g_window,
@@ -484,7 +485,7 @@ void MainWindow::buildUI()
   ImGuiWindowFlags windowFlags = ImGuiWindowFlags_NoDecoration
       | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoSavedSettings
       | ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav
-      | ImGuiWindowFlags_NoMove;
+      | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoBackground;
 
   ImGui::SetNextWindowPos(ImVec2(10, 10), ImGuiCond_Always);
 
diff --git a/examples/viewer/main.cpp b/examples/viewer/main.cpp
index 7e457e7e..6f3b4581 100644
--- a/examples/viewer/main.cpp
+++ b/examples/viewer/main.cpp
@@ -23,6 +23,7 @@ ANARILibrary g_debug = nullptr;
 bool g_enableDebug = false;
 bool g_verbose = false;
 const bool g_true = true;
+const char *g_traceDir = nullptr;
 
 /******************************************************************/
 static std::string pathOf(const std::string &filename)
@@ -97,6 +98,10 @@ static void initializeANARI(MainWindow *window)
   if (g_enableDebug) {
     ANARIDevice dbg = anariNewDevice(g_debug, "debug");
     anari::setParameter(dbg, dbg, "wrappedDevice", ANARI_DEVICE, &dev);
+    if(g_traceDir) {
+      anari::setParameter(dbg, dbg, "traceDir", ANARI_STRING, g_traceDir);
+      anari::setParameter(dbg, dbg, "traceMode", ANARI_STRING, "code");
+    }
     anari::commitParameters(dbg, dbg);
     anari::release(dev, dev);
     dev = dbg;
@@ -120,6 +125,8 @@ void printUsage()
       << "   [{--library|-l} <ANARI library>]\n"
       << "   [{--device|-d} <ANARI device>]\n"
       << "   [{--renderer|-r} <ANARI renderer>]\n"
+      << "   [{--trace|-t} <directory>]\n"
+      << "   [{--scene|-s} <scene>]\n"
       << "   [.obj intput file]"
       << std::endl;
 }
@@ -144,6 +151,8 @@ void parseCommandLine(int argc, const char *argv[])
       g_verbose = true;
     } else if (arg == "--scene" || arg == "-s") {
       g_startupScene = argv[++i];
+    } else if (arg == "--trace" || arg == "-t") {
+      g_traceDir = argv[++i];
     } else {
       g_objFile = arg;
     }
diff --git a/libs/anari_test_scenes/CMakeLists.txt b/libs/anari_test_scenes/CMakeLists.txt
index 1101f651..833d8be9 100644
--- a/libs/anari_test_scenes/CMakeLists.txt
+++ b/libs/anari_test_scenes/CMakeLists.txt
@@ -11,6 +11,7 @@ add_library(${PROJECT_NAME} STATIC
   scenes/gravity_spheres_volume.cpp
   scenes/instanced_cubes.cpp
   scenes/random_spheres.cpp
+  scenes/random_cylinders.cpp
   scenes/scene.cpp
   scenes/textured_cube.cpp
   scenes/attributes.cpp
diff --git a/libs/anari_test_scenes/anari_test_scenes.cpp b/libs/anari_test_scenes/anari_test_scenes.cpp
index dd7ad345..52cf0ecc 100644
--- a/libs/anari_test_scenes/anari_test_scenes.cpp
+++ b/libs/anari_test_scenes/anari_test_scenes.cpp
@@ -12,6 +12,7 @@
 #include "scenes/gravity_spheres_volume.h"
 #include "scenes/instanced_cubes.h"
 #include "scenes/random_spheres.h"
+#include "scenes/random_cylinders.h"
 #include "scenes/textured_cube.h"
 #include "scenes/attributes.h"
 
@@ -35,6 +36,7 @@ static void init()
     scenes["instanced_cubes"] = &sceneInstancedCubes;
     scenes["textured_cube"] = &sceneTexturedCube;
     scenes["random_spheres"] = &sceneRandomSpheres;
+    scenes["random_cylinders"] = &sceneRandomCylinders;
     scenes["attributes"] = &sceneAttributes;
     scenes["file_obj"] = &sceneFileObj;
   }
diff --git a/libs/anari_test_scenes/scenes/random_cylinders.cpp b/libs/anari_test_scenes/scenes/random_cylinders.cpp
new file mode 100644
index 00000000..0b3c441d
--- /dev/null
+++ b/libs/anari_test_scenes/scenes/random_cylinders.cpp
@@ -0,0 +1,135 @@
+// Copyright 2021 The Khronos Group
+// SPDX-License-Identifier: Apache-2.0
+
+#include "random_cylinders.h"
+// std
+#include <random>
+
+namespace anari {
+namespace scenes {
+
+RandomCylinders::RandomCylinders(anari::Device d) : TestScene(d)
+{
+  m_world = anari::newObject<anari::World>(m_device);
+}
+
+RandomCylinders::~RandomCylinders()
+{
+  anari::release(m_device, m_world);
+}
+
+std::vector<ParameterInfo> RandomCylinders::parameters()
+{
+  return {
+      {"numCylinders", ANARI_INT32, int(1e3), "Number of cylinders to generate."},
+      {"radius", ANARI_FLOAT32, 1.5e-2f, "Radius of all cylinders."}
+      //
+  };
+}
+
+anari::World RandomCylinders::world()
+{
+  return m_world;
+}
+
+void RandomCylinders::commit()
+{
+  auto d = m_device;
+
+  // Build this scene top-down to stress commit ordering guarantees
+
+  setDefaultLight(m_world);
+
+  auto surface = anari::newObject<anari::Surface>(d);
+  auto geom = anari::newObject<anari::Geometry>(d, "cylinder");
+  auto mat = anari::newObject<anari::Material>(d, "matte");
+  anari::setParameter(d, mat, "color", "color");
+  anari::commitParameters(d, mat);
+
+  anari::setAndReleaseParameter(
+      d, m_world, "surface", anari::newArray1D(d, &surface));
+
+  anari::commitParameters(d, m_world);
+
+  anari::setParameter(d, surface, "geometry", geom);
+  anari::setParameter(d, surface, "material", mat);
+
+  int numCylinders = getParam<int>("numCylinders", 2e3);
+  float radius = getParam<float>("radius", 1.5e-2f);
+  bool randomizeRadii = getParam<bool>("randomizeRadii", true);
+
+  if (numCylinders < 1)
+    throw std::runtime_error("'numCylinders' must be >= 1");
+
+  if (radius <= 0.f)
+    throw std::runtime_error("'radius' must be > 0.f");
+
+  std::mt19937 rng;
+  rng.seed(0);
+  std::normal_distribution<float> vert_dist(0.5f, 0.5f);
+
+  std::vector<glm::vec3> cylinderPositions(2*(size_t(numCylinders)));
+  std::vector<glm::vec4> cylinderColors(2*(size_t(numCylinders)));
+
+  for (int i = 0;i<numCylinders;++i) {
+    auto &a = cylinderPositions[2*i];
+    a.x = vert_dist(rng);
+    a.y = vert_dist(rng);
+    a.z = vert_dist(rng);
+
+    auto &b = cylinderPositions[2*i+1];
+    b.x = a.x + 0.1*vert_dist(rng);
+    b.y = a.y + 0.1*vert_dist(rng);
+    b.z = a.z + 0.1*vert_dist(rng);
+  }
+
+  for (auto &s : cylinderColors) {
+    s.x = vert_dist(rng);
+    s.y = vert_dist(rng);
+    s.z = vert_dist(rng);
+    s.w = 1.f;
+  }
+
+  anari::setAndReleaseParameter(d,
+      geom,
+      "vertex.position",
+      anari::newArray1D(d, cylinderPositions.data(), cylinderPositions.size()));
+  anari::setParameter(d, geom, "radius", radius);
+  anari::setParameter(d, geom, "caps", "none");
+
+  anari::setAndReleaseParameter(d,
+      geom,
+      "vertex.color",
+      anari::newArray1D(d, cylinderColors.data(), cylinderColors.size()));
+
+  if (randomizeRadii) {
+    std::normal_distribution<float> radii_dist(radius / 10.f, radius);
+
+    std::vector<float> cylinderRadii((size_t(numCylinders)));
+    for (auto &r : cylinderRadii)
+      r = radii_dist(rng);
+
+    anari::setAndReleaseParameter(d,
+        geom,
+        "primitive.radius",
+        anari::newArray1D(d, cylinderRadii.data(), cylinderRadii.size()));
+  }
+
+  anari::commitParameters(d, geom);
+  anari::commitParameters(d, mat);
+  anari::commitParameters(d, surface);
+
+  // cleanup
+
+  anari::release(d, surface);
+  anari::release(d, geom);
+  anari::release(d, mat);
+}
+
+TestScene *sceneRandomCylinders(anari::Device d)
+{
+  return new RandomCylinders(d);
+}
+
+} // namespace scenes
+} // namespace anari
\ No newline at end of file
diff --git a/libs/anari_test_scenes/scenes/random_cylinders.h b/libs/anari_test_scenes/scenes/random_cylinders.h
new file mode 100644
index 00000000..d3ac85b8
--- /dev/null
+++ b/libs/anari_test_scenes/scenes/random_cylinders.h
@@ -0,0 +1,29 @@
+// Copyright 2021 The Khronos Group
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "scene.h"
+
+namespace anari {
+namespace scenes {
+
+TestScene *sceneRandomCylinders(anari::Device d);
+
+struct RandomCylinders : public TestScene
+{
+  RandomCylinders(anari::Device d);
+  ~RandomCylinders();
+
+  std::vector<ParameterInfo> parameters() override;
+
+  anari::World world() override;
+
+  void commit() override;
+
+ private:
+  anari::World m_world{nullptr};
+};
+
+} // namespace scenes
+} // namespace anari
diff --git a/libs/debug_device/CodeSerializer.cpp b/libs/debug_device/CodeSerializer.cpp
index d892f349..9f30f54e 100644
--- a/libs/debug_device/CodeSerializer.cpp
+++ b/libs/debug_device/CodeSerializer.cpp
@@ -486,26 +486,27 @@ void CodeSerializer::anariNewFrame(ANARIDevice device, ANARIFrame result) {
    out << " = anariNewFrame(device);\n";
 }
 
-void CodeSerializer::anariMapFrame(ANARIDevice device, ANARIFrame object, const char* channel, const void *mapped) {
+void CodeSerializer::anariMapFrame(ANARIDevice device, ANARIFrame object, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType, const void *mapped) {
    uint64_t local = locals++;
+   sanitized_name schannel{channel};
    out << "uint32_t width_local" << local << ";\n";
    out << "uint32_t height_local" << local << ";\n";
    out << "ANARIDataType type_local" << local << ";\n";
-   out << "const void *mapped_" << channel << local << " = anariMapFrame(device, ";
+   out << "const void *mapped_" << schannel << local << " = anariMapFrame(device, ";
    printObjectName(object);
    out << ", \"" << channel << "\", &width_local" << local;
    out << ", &height_local" << local;
    out << ", &type_local" << local;
    out << ");\n";
 
+   out
+      << "// returned width = " << (width ? std::to_string(*width) : "(null)")
+      << " height = " << (height ? std::to_string(*height) : "(null)")
+      << " format = " << (pixelType ? anari::toString(*pixelType) : "(null)")
+      << "\n";
+
    if(auto info = dd->getDynamicObjectInfo<DebugObject<ANARI_FRAME>>(object)) {
-      ANARIDataType mappingType = ANARI_UNKNOWN;
-      if(std::strncmp(channel, "color", 5)==0) {
-         mappingType = info->colorType;
-      } else if(std::strncmp(channel, "depth", 5)==0) {
-         mappingType = info->depthType;
-      }
-      out << "image(\"" << channel << "\", mapped_" << channel << local << ", ";
+      out << "image(\"" << channel << "\", mapped_" << schannel << local << ", ";
       out << "width_local" << local << ", " << "height_local" << local << ", " << "type_local" << local << ");\n";
    }
 }
diff --git a/libs/debug_device/CodeSerializer.h b/libs/debug_device/CodeSerializer.h
index df345a50..908beddc 100644
--- a/libs/debug_device/CodeSerializer.h
+++ b/libs/debug_device/CodeSerializer.h
@@ -42,7 +42,7 @@ class CodeSerializer : public SerializerInterface {
    void anariRetain(ANARIDevice device, ANARIObject object) override;
    void anariGetProperty(ANARIDevice device, ANARIObject object, const char* name, ANARIDataType type, void* mem, uint64_t size, ANARIWaitMask mask, int result) override;
    void anariNewFrame(ANARIDevice device, ANARIFrame result) override;
-   void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, const void *mapped) override;
+   void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType, const void *mapped) override;
    void anariUnmapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) override;
    void anariNewRenderer(ANARIDevice device, const char* type, ANARIRenderer result) override;
    void anariRenderFrame(ANARIDevice device, ANARIFrame frame) override;
diff --git a/libs/debug_device/DebugBasics.cpp b/libs/debug_device/DebugBasics.cpp
index c6a9bf03..cbc6cdd2 100644
--- a/libs/debug_device/DebugBasics.cpp
+++ b/libs/debug_device/DebugBasics.cpp
@@ -275,7 +275,7 @@ void DebugBasics::anariGetProperty(ANARIDevice device, ANARIObject object, const
 void DebugBasics::anariNewFrame(ANARIDevice device) {
     (void)device;
 }
-void DebugBasics::anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) {
+void DebugBasics::anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType) {
     DEBUG_FUNCTION_SOURCE(anariMapFrame, frame)
     (void)device;
     (void)channel;
diff --git a/libs/debug_device/DebugBasics.h b/libs/debug_device/DebugBasics.h
index ef6754b9..fee78504 100644
--- a/libs/debug_device/DebugBasics.h
+++ b/libs/debug_device/DebugBasics.h
@@ -40,7 +40,7 @@ class DebugBasics : public DebugInterface {
     void anariRetain(ANARIDevice device, ANARIObject object) override;
     void anariGetProperty(ANARIDevice device, ANARIObject object, const char* name, ANARIDataType type, void* mem, uint64_t size, ANARIWaitMask mask) override;
     void anariNewFrame(ANARIDevice device) override;
-    void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) override;
+    void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType) override;
     void anariUnmapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) override;
     void anariNewRenderer(ANARIDevice device, const char* type) override;
     void anariRenderFrame(ANARIDevice device, ANARIFrame frame) override;
diff --git a/libs/debug_device/DebugDevice.cpp b/libs/debug_device/DebugDevice.cpp
index 639d5f6e..bf108378 100644
--- a/libs/debug_device/DebugDevice.cpp
+++ b/libs/debug_device/DebugDevice.cpp
@@ -701,12 +701,12 @@ const void *DebugDevice::frameBufferMap(ANARIFrame fb,
     uint32_t *height,
     ANARIDataType *pixelType)
 {
-  debug->anariMapFrame(this_device(), fb, channel);
+  debug->anariMapFrame(this_device(), fb, channel, width, height, pixelType);
   const void *mapped = anariMapFrame(
       wrapped, unwrapHandle(fb), channel, width, height, pixelType);
 
   if (serializer) {
-    serializer->anariMapFrame(this_device(), fb, channel, mapped);
+    serializer->anariMapFrame(this_device(), fb, channel, width, height, pixelType, mapped);
   }
 
   return mapped;
diff --git a/libs/debug_device/DebugInterface.h b/libs/debug_device/DebugInterface.h
index d97ac715..016256f0 100644
--- a/libs/debug_device/DebugInterface.h
+++ b/libs/debug_device/DebugInterface.h
@@ -35,7 +35,7 @@ class DebugInterface {
     virtual void anariRetain(ANARIDevice device, ANARIObject object) = 0;
     virtual void anariGetProperty(ANARIDevice device, ANARIObject object, const char* name, ANARIDataType type, void* mem, uint64_t size, ANARIWaitMask mask) = 0;
     virtual void anariNewFrame(ANARIDevice device) = 0;
-    virtual void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) = 0;
+    virtual void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType) = 0;
     virtual void anariUnmapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) = 0;
     virtual void anariNewRenderer(ANARIDevice device, const char* type) = 0;
     virtual void anariRenderFrame(ANARIDevice device, ANARIFrame frame) = 0;
diff --git a/libs/debug_device/DebugSerializerInterface.h b/libs/debug_device/DebugSerializerInterface.h
index 042d6a91..f087e850 100644
--- a/libs/debug_device/DebugSerializerInterface.h
+++ b/libs/debug_device/DebugSerializerInterface.h
@@ -35,7 +35,7 @@ class SerializerInterface {
     virtual void anariRetain(ANARIDevice device, ANARIObject object) = 0;
     virtual void anariGetProperty(ANARIDevice device, ANARIObject object, const char* name, ANARIDataType type, void* mem, uint64_t size, ANARIWaitMask mask, int result) = 0;
     virtual void anariNewFrame(ANARIDevice device, ANARIFrame result) = 0;
-    virtual void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, const void *mapped) = 0;
+    virtual void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType, const void *mapped) = 0;
     virtual void anariUnmapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) = 0;
     virtual void anariNewRenderer(ANARIDevice device, const char* type, ANARIRenderer result) = 0;
     virtual void anariRenderFrame(ANARIDevice device, ANARIFrame frame) = 0;
diff --git a/libs/debug_device/EmptySerializer.h b/libs/debug_device/EmptySerializer.h
index 1026a262..dd7c72e9 100644
--- a/libs/debug_device/EmptySerializer.h
+++ b/libs/debug_device/EmptySerializer.h
@@ -37,7 +37,7 @@ class EmptySerializer : public SerializerInterface {
    void anariRetain(ANARIDevice device, ANARIObject object) override { }
    void anariGetProperty(ANARIDevice device, ANARIObject object, const char* name, ANARIDataType type, void* mem, uint64_t size, ANARIWaitMask mask, int result) override { }
    void anariNewFrame(ANARIDevice device, ANARIFrame result) override { }
-   void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, const void *mapped) override { }
+   void anariMapFrame(ANARIDevice device, ANARIFrame frame, const char* channel, uint32_t *width, uint32_t *height, ANARIDataType *pixelType, const void *mapped) override { }
    void anariUnmapFrame(ANARIDevice device, ANARIFrame frame, const char* channel) override { }
    void anariNewRenderer(ANARIDevice device, const char* type, ANARIRenderer result) override { }
    void anariRenderFrame(ANARIDevice device, ANARIFrame frame) override { }