Demo of Not-Quite Infinite Terrain (Mars)

There's a great 3-d demonstration program, by Humus which displays an infinite landscape of randomly generated hills and valleys based on the Perlin Noise function. It will give your T&L-enabled video card a real workout. I have modified this program so it will display actual Martian terrain data collected by the Mars Global Surveyor probe. You can fly around the surface of Mars in an interactive relief map. Visit Olympus Mons, Valles Marineris, or the Hellas basin and view them from any angle.

The demo display MEGDR Version 2 topological data (.img) files. Each file contains about 1/16 of the Martian surface, 12 million square kilometers, with 60 million data points. The files are about 120 MB so they are available separately from the MOLA Gridded Topographic Map page.

To run the demo, just put one of the image files in the directory with the MarsDemo executable and rename it to topo.img, then run MarsDemo.

Press F while the demo is running to toggle a display of your current position (relative to the NW corner of the map file) in degrees of longitude, latitude, and the terrain elevation in meters at your position.

You can see a global view here to find interesting stuff to look at.

Visit Humus' site for more on the Infinite Terrain demo. Humus did almost all the work on the Mars Demo.

If you just want the demo, download this. Remember you need to get the data files from here. There are Windows and Linux (slackware) executables included.

If you want to build the demo the way I did, you'll need my slightly bastardized version of Humus' framework. You can download that here.

The changes to Humus' framework consist of the following:

• Change to build on Slackware Linux
• Change to support the vertex array range extension for quick access to vertex information on nVidia cards. This was mainly a learning exercise for me since my current nVidia card only has 32 MB of memory, which isn't really enough to benefit this demo. I'd be interested in hearing from people with heftier nVidia cards to see if this works out for them. It is supposed to give the same performance benefit as ATI's array object buffer extension.

If you already have Humus' framework and want to build against that, you'll need a slightly tweaked version of the MarsDemo source.

To come, actual roughness, ice coverage and albedo data!