3D Models

Greg has been in love with 3D modeling and virtual worlds since the Philips days, but it's taken him more than two decades to put together a web page gathering them into one place. Better late than never, though, eh?

The original ones were in VRML, and once upon a time, browser plugins to view such things were common. Alas, that is no longer the case. However, there is a silver lining: virtually all modern browsers have WebGL accelerated 3D support built in, and the three.js library makes invoking that support fairly easy...though, of course, there's a learning curve to convert from the VRML mindset to that of three.js.

Greg's favorite is a model of the local universe, which slowly revolves and zooms in and out (use the controls in the corner to stop that if you wish). Unlike its VRML predecessor, it has no functioning viewpoints (can't seem to get them to work right), which means the view-from-the-origin, find-me-a-constellation feature is missing:

This is a less-complete but more-accurate variant, limited to the galaxies within 10 or 11 Mpc of the Milky Way, all of which have reasonably accurate distance measurements (as well as labels). The blue ones are the more distant ones (non-members of the Local Group, which extends only to about 1.4 Mpc); the green ones are members of the Local Group but not bound to any of the three spirals; the orange ones are satellites of the Milky Way; the pink ones are satellites of Andromeda; and the purple one may or may not be a satellite of the Triangulum Galaxy:

At the other end of the complexity spectrum, this simple one was by request of mathematician John Baez:

Quite a few of the models below are very simple conversions of GPS latitude/longitude/elevation data to "extrusions" (VRML terminology), a.k.a. TubeGeometry (three.js nomenclature). Greg hasn't yet entirely automated the conversion, but he's getting close. This pair is based on GPS traces in the Bay Area. The first was a hike along the northwest coast of San Francisco (10x vertical exaggeration), and the second is a set of vertically offset bike rides through Mountain View, Sunnyvale, and Alviso (virtually flat terrain):

    

These are a bunch of Tahoe-area ski tracks; they're all to the same scale (the vertical is exaggerated 2x in each), and like the SF hike model above, time always progresses from green to purple:

(The white segment in the Alpine Meadows/Squaw Valley one is a portion of the bus trip home; there was an unfortunate incident with the GPS's "start/stop" button near the end of the day. :-/ ) Alas, snow in the Tahoe region has been uninspiring for quite a few years now, with the exception of 2017...which, sadly, was the year Greg got in exactly 2.5 hours of skiing. :-( Many of the resorts (Kirkwood, Sierra Ski Ranch, even Heavenly and Squaw) are much bigger than they appear here, but there simply hasn't been enough snow coverage, and in some cases high winds have closed large areas of the mountain. And back when there was plenty of snow, Greg didn't have a tracking GPS. Le sigh...

more to come ...