[vtkusers] COLOR_SCALARS in the ASCII Legacy Format

[Gerrit Groot]

Is this actuallt the right forum for my question?
(I may be mistaken)

--- El jue, 10/2/11, Gerrit Groot <gerritgroot at yahoo.es> escribió:

> De: Gerrit Groot <gerritgroot at yahoo.es>
> Asunto: [vtkusers] COLOR_SCALARS in the ASCII Legacy Format
> Para: vtkusers at vtk.org
> Fecha: jueves, 10 de febrero, 2011 19:04
> Hi,
> 
> I'm new to this mailing list and hope I'm not asking for
> something obvious. Searching on the web, I couldn't find the
> answer, so I subscribed. (In fact I don't even know what a
> mailing list exactly is, but anyway...)
> 
> My question is about the Vtk Legacy File format.
> 
> If I want to give a color to, for example, points, I can
> use COLOR_SCALARS, but the variable definition in
> COLOR_SCALARS remains unclear to me, especially beyond a
> certain extend. I use paraview to view my results.
> 
> About the format now. So far, by trial and error I
> discovered the following:
> 
> In the header I give "COLOR_SCALARS name number"
> 
> For number=1:
> - The color varies from black (0.0) to white (1.0)
> 
> For number=2:
> - The first value gives the greyscale (0.0=black and
> 1.0=white) and the second value the transparency
> (0.0=transparent; 1.0=fully opaque)
> 
> for number=3
> - The three floats seem to represent rgb values from 0%=0.0
> to 100%=1.0
> 
> for number=4 it becomes unclear
> - Here I expected the fourth value to be the alpha
> transparency, but at least visualising with ParaView, the
> fourth value does not seem to have any effect at all!
> 
> Moreover, paraview seems also to accept number=5, number=6
> etc.
> 
> My questions are:
> 
> * What is the fourth value? And why doesn't it have any
> effect?
> * How are the COLOR_SCALARS defined for number>4?
> 
> Thanks in advance,
> 
> Gerrit
> 
> 
>       
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
>