michaelgalloy.com

At the suggestion of Anne in the comments of a previous posting about line-integral convolution (LIC) algorithm for vector field visualization, I tried pink noise as the input texture map. I think this looks pretty good compared to using white noise or smoothed white noise, but I’m still looking for better ways to show the magnitude and which direction along a flow line the field is really pointing.

A .sav file and API documentation for the POV-Ray object graphics destination that I’ve mentioned before are available here.

I spent some time improving the POV-Ray destination for object graphics I talked about in a previous article. I can now produce visualizations of actual data (like the one on the right) using this destination and its related library of classes.

My goals for this destination are two-fold:

1. Create better renderings of pure IDL object graphics scenes (with no POV-Ray knowledge necessary).
2. Ability to use POV-Ray specific features using custom object graphics classes. These classes render in some way in IDL, but produce effects in POV-Ray that can’t be completely replicated in IDL.

I think the current VISgrPOVRay class supports objective 1 common 3-dimensional object graphics scenes, but lacks support for every property provided by the IDL library. Support for most properties can be easily done as needed.

The second objective requires creating new subclasses of classes in the IDL library with additional properties. For example, there is a VISgrPOVRayLight class which inherits from IDLgrLight class, but also provides support for the POV-Ray area light type. There is a VISgrPOVRayView which provides for features like focal blur in addition to the properties of the IDLgrView. There are also subclasses for grid planes, streamlines, and POV-Ray polygon graphics atoms as well as a finish attribute class. More classes can be added to support additional POV-Ray features as necessary.

Winners of the NSF’s 2007 Science and Engineering Visualization Challenge were announced yesterday. Maybe this will give some inspiration for the Image Competition with ITT VIS’ User Group Meeting. Deadline for submissions is today!

I made a new version of the IDL operators chart that adds information about which operators use the thread pool and cleans up the graphics a bit (over the old version).

I recently stumbled across some great flow visualizations on the Visualization section of NASA Advanced Supercomputing Division’s website. I couldn’t find any references to what was used to produce the animations or how much CPU time they took to render.

I would also like to see the “hyperwall”, a 7 by 7 grid of flat-panel displays each driven by its computer with a high-end graphics card, mentioned on the site.

The distinctive style of Edward Tufte’s books has inspired a project to create a LaTeX template to make mimicking his style easier (Tufte quote: “Don’t get it original—get it right”). Installation is simple (just drop a .cls file into the same directory as your .tex file), though there are many prerequisite packages.

The example given on the project page demonstrates and documents the capabilities of the template.

Fluid-Forms lets you select a region of the Earth via Google Maps and creates a physical model made of wood. They laminate layers of wood together in alternating colors to produce contour lines when the wood is carved. There are several different models (including a clock).

I would get a model of Boulder if it didn’t cost 191 Euros (about $284 right now).

The values for color tables 10 and 11 of the Brewer color tables were swapped in the last update. The new version keeps YlOrRd as 10 and YlOrBr as 11, but makes the values correct. See below for what the color tables look like.

By the way, I was thinking of adding more color tables. matplotlib has more color tables that have a compatible license. Are there other color tables that people are fond of?

While producing some flow visualizations lately, I've found that smoothing a random texture gives less pixellated looking result than using a purely random texture. I added a texture keyword a while ago so that a common texture could be used for several LIC images, but now I've discovered that playing around with the texture a bit can be useful. I've been creating the texture with:

Click on the thumbnail image to see the full image.