June 22, 2011

Open Source Scientific Visualization (vs. Information Visualization)

A colleague recently sent me a link to ParaView, an open source scientific visualization tool.  In my day job I usually work with information visualization techniques but that wasn't always the case;  my visualization career began with scientific visualization (a post-doc working with 3D confocal microscope data).
So what's the difference between scientific and information visualization?  According to Wikipedia, scientific visualization is:
... primarily concerned with the visualization of three-dimensional phenomena (architectural, meteorological, medical, biological, etc.), where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps with a dynamic (time) component

and information visualization is:
... the visual representation of large-scale collections of non-numerical information, such as files and lines of code in software systems, library and bibliographic databases, networks of relations on the internet, and so forth

A couple of examples are shown at the end of this post.

Personally, I think the main difference is the domains from which the data to be visualized is drawn.  Scientific visualization tends to deal with data from the physical sciences; astronomy, meteorology, physics, engineering, geology, biomedicne etc. whereas information visualization works with data sets from different (non-physical) science domains and non-scientific domains.  As a result the nature of the data and the questions being asked also differ and lend themselves to different visualization techniques.  So, for example, scientific visualization makes use of volume rendering and vector field diagrams, which provide a direct view of physical data, whereas information visualization uses parallel coordinates and network diagrams which are abstract representations of non-physical data.  These are generalisations of course; information visualizations can be applied to physical data and scientific visualizations can be used with non-physical data, but as a general rule the difference is the data domains.

So, returning to ParaView, upon seeing it I wondered what other FOSS scientific visualization tools were available these days.  Here's what I found:
  • ParaView: built atop of the venerable VTK visualization toolkit
  • VisIT: developed by the Department of Energy to visualize the results of terascale simulations
  • OpenDX: IBM open-sourced their Data Explorer product

If you know of any others then please let me know.