[vtkusers] vtkSmartVolumeMapper in GPURenderMode access violation

[sean.larkin at lickenbrocktech.com]

Hello,
I am using vtk 6.0 with Qt 4.8 on Windows 7 64-bit.  I have encountered
a problem when using vtkSmartVolumeMapper in GPURenderMode.  I try to
render the volume, but get access violation errors before it can be
rendered a first time.  I have tracked this issue down to the dimensions
of the input volume data.  The error occurs when the volume dimensions
are not square, and also seemingly random.  I can render any size volume
if I use the vtkSmartVolumeMapper RayCastRenderMode, which uses the CPU
for rendering.  And I can also use the texturerendermode option for any
size volume as well.  I tracked the call to
vtkSmartVolumeMapper::ConnectFilterInput() using the call stack.  The
access violation appears to be the result of an issue with image
resampling, as the calling function is ComputeRenderMode() at what I
think is this "this->ConnectFilterInput(this->GPUResampleFilter)".  My
guess is that the resampler is using a ceil() or something to calculate
the new dimensions, and these new dimensions point past the memory
location of the data.  Although, it seems as if someone else would have
encountered this issue already and reported it.  I could not find
anything in the vtk bug tracker issues.  Could anyone verify this issue
for me or help me fix this issue?  
I've been work with raw data files in 8-bit and 16-bit format.  The data
reads in fine, and as I said I can render this data for any dimensions
using the other rendering options.  

Thanks,
Sean