Recently, I’ve been very busy with POV-Ray and Matlab. This led me onto a website of a (POV-Ray) visualisation specialist, Paul Bourke. Here, I found useful information on making and using a 3D density file.
A 3D density file is a file that contains density values for each volume element (voxel) in a volume. Magnetic resonance imaging (MRI) is one example of that, but also gas clouds (e.g. as in space), or simply electron density volumes.
Rendering this by means of POV-Ray takes an enormous amount of time, but eliminating the “scattering” behaviour of the medium saves much time.
I’d advise all parties interested in data visualisation to take a look at Paul Bourke’s website. It is filled with many goodies and many good images depicting the many capabilities of the POV-Ray raytracing software.
On a related note, there is a nice article out called “Digital Doctoring: How to tell the real from the fake” by Hany Farid. It discusses the artefacts created when manipulating images. It is a nice introduction to image doctoring effects, but unfortunately is very light on details. Rumor has it that Adobe is working on integrating the details in Photoshop®.