VTK and Volume Visualization - My Octopress Blog

This week for Scientific Visualization, we’re talking about volume rendering and using VTK to explore some data. I got some datasets from The Volume Library and after a little tinkering, got VTK to render them. (And now a quick aside on how to do this as I didn’t find much information on the subject).

I used a tool (pvm2raw) available as part of the V^3 library to convert the pvm files to raw, but VTK requires its own simple header. I actually found that this particular header didn’t work (perhaps a VTK versioning problem?) and so taking guidance from this, checked the header of one of the VTK-included volumes:

head VTKData/ironProt.vk

This header more or less included a little information on the grid size, spacing and representation of the data:

# vtk DataFile Version 1.0
&lt;Name of File&gt;

BINARY

DATASET STRUCTURED_POINTS

DIMENSIONS &lt;x&gt; &lt;y&gt; &lt;z&gt;
ASPECT_RATIO 1 &lt;y/x&gt; &lt;z/x&gt;
ORIGIN 0 0 0

POINT_DATA &lt;x * y * z&gt;
SCALARS scalars &lt;unsigned_char|unsigned_short&gt;
LOOKUP_TABLE default
&lt;remember to include a newline here&gt;

Concatenating the header with the raw: <div class=’bogus-wrapper’>

bash $> cat header CT-Head.raw > CT-Head.vtk

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At that point, I was in business and was able to move on to generating pretty pictures. Granted, these datasets are pretty sparse, but still VTK did a pretty reasonable job. Update: a comment asked for a little bit more detail on this assignment, and so I’m including my report for the project.

[gallery link=”file” orderby=”ID”]

I was amazed today that we can see inside of things… without taking them apart. What an age to live in. Especially the virtual autopsy table I read about recently. In 20 years, we’ll have Firefly-style real-time holographic body scans (ignore music, skip to 0:45):