[vtkusers] Volume Rendering problem

[Lisa Sobierajski Avila]

Hello Naoko,

I think the problem is your sampling rate - your data spacing is 1/20 and 
the default sampling distance for ray casting is 1 - so you are sampling 1 
of every 20 voxels. You should change the sample distance of the ray caster 
to something like 1/40.

Lisa


At 09:32 PM 9/24/2000, Naoko Takaya wrote:
>Hello Lisa,
>
>  I have set the data type to unsigned short by this,
>  vtkScalars *scalars = vtkScalars::New();
>  ......
>  scalars->SetDataTypeToUnsignedShort();
>  ........
>
>  Naoko
>
> > > -----Original Message-----
> > > From: Lisa Sobierajski Avila [mailto:lisa.avila at kitware.com]
> > > Sent: Friday, September 22, 2000 12:30 PM
> > > To: Naoko Takaya; Vtk Vtk
> > > Subject: Re: [vtkusers] Volume Rendering problem
> > >
> > >
> > > Hello Naoko,
> > >
> > > What type of scalars do you have? The ray caster can only
> > render unsigned
> > > char and unsigned short data.
> > >
> > > Lisa
> > >
> > >
> > > At 11:18 PM 9/21/2000, Naoko Takaya wrote:
> > > >To all vtkusers,
> > > >
> > > >Howdy!!
> > > >
> > > >I have a pblm with Volume Rendering.
> > > >I use ;
> > > >
> > > >vtkSrutcturedPoints
> > > >vtkPiecewiseFunction
> > > >vtkVolumeProperty
> > > >vtkVolumeRayCastCompositeFunction
> > > >vtkVolumeRayMapper
> > > >vtkVolume
> > > >
> > > >When I see the result, it looks OK, but when turning it around
> > > >and having a closer look, the shape changes every time
> > > >I rotate. Why is this?
> > > >Some kind of planes and lines appear and not the solid shape.
> > > >
> > > >Also, I don't exactly understand what "AddSegment" ( member of
> > > >vtkPiecewiseFuntion ) does to the shape.
> > > >I read the manual and said that it adds line segment to the
> > > >function and removes the points between the specified points.
> > > >But why use this when setting the color and opacity to the volume?
> > > >
> > > >This might be a simple question but I hope you would help me.
> > > >Any help would very much be appreciated!!
> > > >
> > > >Thank you in advance!!
> > > >
> > > >PS
> > > >    Just in case, I attached my pgm with.
> > > >
> > > >********************************************************
> > > >*                Naoko Takaya                               *
> > > >*                                                                    *
> > > >*       e-mail: takaya at cv.cs.ritsumei.ac.jp         *
> > > >*                                                                    *
> > > >*********************************************************
> > >
> > >
>
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