_volumeMapper = vtkVolumeRayCastMapper::New();
_volumeMapper->SetVolumeRayCastFunction(_compositeFunction);
_volumeMapper->SetClippingPlanes( _volumePlanes );
_volumeMapper->AutoAdjustSampleDistancesOn();
_volumeProperty = vtkVolumeProperty::New();
_volumeProperty->SetInterpolationTypeToLinear();
_volumeMapper = vtkVolumeRayCastMapper::New();
_volumeMapper->SetVolumeRayCastFunction(_compositeFunction);
_volumeMapper->SetClippingPlanes( _volumePlanes );
_volumeMapper->AutoAdjustSampleDistancesOn();
_volumeProperty = vtkVolumeProperty::New();
_volumeProperty->SetInterpolationTypeToLinear();