[vtkusers] Maximum and minimum intensity blend in

[Michael Knopke]

Hi Shashwatch,

 

What exactly do you need to get hardware MIP working? I'm using it already
without problems (besides the intensity prob). Actually this is only the
change of blendingfunction to max blending (unfortunately minimum blending
doesn't work, but I didn't really spend much time on it).

So in order to change the vtkOpenGLVolumeTextureMapper3D you need to load
the openGL extension and change the blending equation (both included in
examples) that's it. If you look through the code you will notice that I
changed the equation only for 1 component data, because I don't need more.
But this is no prob just change the equation in those functions as well. I
think you'll also have to change the file vtkVolumeMapper.h to have the
option to change the blending:

 

void SetBlendModeToMaximumIntensity()

    { this->SetBlendMode( vtkVolumeMapper::MAXIMUM_INTENSITY_BLEND ); }

 

Needs to be added. Anyway, I'll send you all my modified files, so you can
try them. 

I'd be very interested in improving the hardware renderer. But I think the
actual volumerenderer is quite outdated (it colormaps all data (with cpu)
before sending it to videomemory thus being slower and using more memory
than other algorithms). What we need are renders that are written in
shaderlanguage, it's easier to write. I was trying to get some shaders to
work but it seems that the VTK shader support isn't ready yet. (no
improvement since October last year).

 

Regards,

 

Michael

 

 

 

 

 

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