Modify QtFreeRender.cpp in the following way to use volume rendering and gpuvolumemapper3d:

1. Add line to includes:

#include "mitkCoreExtObjectFactory.h"

2. Change line

node->SetProperty("volumerendering", mitk::BoolProperty::New(false));
to
node->SetProperty("volumerendering", mitk::BoolProperty::New(true));

3. Add line RegisterCoreExtObjectFactory();

after

mitk::GlobalInteraction::GetInstance()->Initialize("global");

Then execute QtFreeRender.cpp application with file Pic3D.nrrd as parameter

Result: Error message displayed:

ERROR: In MITKBuild\VTK-src\Filtering\vtkDemandDrivenPipeline.cxx, line 727
vtkStreamingDemandDrivenPipeline (0CCE8390): Input port 0 of algorithm vtkImageChangeInformation(0CCDE4E8) has 0 connections but is not optional.

And 3D renderer window shows no content.

Works okay when not activating VolumeRendering or when not registering the Extended Object Factory (so that gpuvolumemapper3d is not used)