[vtkusers] change contrast in volume object (it's too dark)

[powerhouseofexcellence]

Ok very good point, I had the background color clearing to black, if I
change it to white it looks very nice. I think my opacities are just
way too low. And also I haven't defined and ambient/specular/diffuse
values, I guess it's just using defaults for those. I will try playing
around with those.

On 8/18/05, Lisa Avila <lisa.avila at kitware.com> wrote:
> Hi,
> 
> First you need to determine why your image is dark. Is it dark because you
> are using shading and 1) don't have appropriate lighting parameters
> (ambient, diffuse, specular) or 2) don't have well-defined gradients in the
> data? Or, is it dark because your opacity function is too low and you are
> "seeing through" the whole volume (seeing mostly the background color)? Or
> is it dark because you have dark colors in your color transfer function?
> The solution is different depending on the reason for your dark image.
> 
> Lisa
> 
> At 09:33 AM 8/18/2005, powerhouseofexcellence wrote:
> >Hi Amy,
> >
> >In principle it should just be a matter of:
> >
> >this->WindowLevel->SetInput(this->ImageData);
> >this->VolumeMapper->SetInput(this->WindowLevel->GetOutput());
> >
> >I am afraid it will kill my machine to do window/level on the whole
> >image data which probably has about 50 slices - when I try window
> >leveling it will do the calculation for the whole image data container
> >right? Are there any shortcuts or is this nothing to be concerned
> >about?
> >
> >Thanks
> >
> >On 8/18/05, Amy Squillacote <amy.squillacote at kitware.com> wrote:
> > > You should be able to use vtkImageMapToWindowLevelColors to do what
> > > you want to do. The on-line documentation for that class is here:
> > >
> > http://www.vtk.org/doc/nightly/html/classvtkImageMapToWindowLevelColors.html.
> > >
> > > - Amy
> > >
> > > At 11:01 PM 8/17/2005, powerhouseofexcellence wrote:
> > > >Hello,
> > > >
> > > >I have a volume rendering going on, but the contrast of the volume is
> > > >very poor, it's kind of difficult to see. Is there a way to implement
> > > >a window/level function on the volume object? Or do I shift the values
> > > >in my opacity/color transfer functions to create a window/level type
> > > >effect?
> > > >
> > > >Thanks
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> 
>