[vtkusers] problem to define RGB

[Malcolm Drummond]

Hi
I'm not sure how it works under 4.x but under 3.x you can create vtkScalars
as an array of unsigned char with 4 components. eg ...

vtkScalars seismic
seismic SetDataTypeToUnsignedChar
seismic SetNumberOfComponents 4
seismic SetNumberOfScalars $n

The mapper will pass this straight through - each scalar is seen as RGBA.
Hope this helps.

Malcolm

----- Original Message -----
From: Elkin Arroyo <elkin at kana.stanford.edu>
To: <vtkusers at public.kitware.com>
Sent: Wednesday, November 14, 2001 1:52 AM
Subject: [vtkusers] problem to define RGB


>
> Hi VTKusers
>
> Right now we are trying do display some seismic data using
> VTK libraries, sesimic images are just a single 3D array
> of values (amplitudes), and a colormap to represent it in
> color.
> So we used vtkStructuredPoints and we defined
> a  vtkLookUpTable and  it worked ok. But now we want
> to display some kind of texture mapping, wich is to
> display the amplitudes along with other value called
> "RMS velocities"
>
> Therefore now we need to input 3
> different scalar values to each point in the
> vtkStructuredPoints, each one of this values corresponding respectively
> to the R,G,B components of the color image. Do you happen to know how we
> can plot it ?
>
> Thanks beforehands
>
> Elkin Arroyo
> Numerica Ltda
>
>
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