message: implement missing object types in MPIDistributedDevice
diff: @@ -365,9 +365,11 @@ namespace ospray {
  return createLocalObject<Geometry, OSPGeometry>(type);
  }
  - OSPMaterial MPIDistributedDevice::newMaterial(const char *, const char *)
  + OSPMaterial MPIDistributedDevice::newMaterial(const char *renderer_type,
  + const char *material_type)
  {
  - NOT_IMPLEMENTED;
  + auto *instance = Material::createInstance(renderer_type, material_type);
  + return (OSPMaterial)instance;
  }
  OSPTransferFunction
  @@ -427,14 +429,16 @@ namespace ospray {
  }
  }
  - void MPIDistributedDevice::setMaterial(OSPGeometry, OSPMaterial)
  + void MPIDistributedDevice::setMaterial(OSPGeometry _geom, OSPMaterial _mat)
  {
  - NOT_IMPLEMENTED;
  + auto *geom = lookupObject<Geometry>(_geom);
  + auto *mat = lookupObject<Material>(_mat);
  + geom->setMaterial(mat);
  }
  - OSPTexture MPIDistributedDevice::newTexture(const char *)
  + OSPTexture MPIDistributedDevice::newTexture(const char *type)
  {
  - NOT_IMPLEMENTED;
  + return createLocalObject<Texture, OSPTexture>(type);
  }
  void MPIDistributedDevice::sampleVolume(float **,
  