Geocart 3.1 shaping up

[daan]

Happy summer!

We at Mapthematics have been working hard at our first upgrade to Geocart 3. Our primary focus has been to replicate the remaining functionality from Geocart 2 missing in Geocart 3 (but beefed up to the industrial and usability standards of Geocart 3). However, you will find more goodness, including bug fixes, new projections, and new functionality. Expect to see soon:

• • Generalization: Joining the venerable Douglas-Peucker, new to 3.1 will be Visvalingam-Whyatt and Bézier curve generalization. Bézier generalization can be applied after first generalizing with Douglas-Peucker or Visvalingam-Whyatt, or it can be applied to the original data. You can specify the level of generalization you want.
  
  • Cleaned-up vector data sets: Geocart will automatically join up contiguous open polygons, even those whose head and tail points are slightly misaligned. This will work for any vector data sets, but we intend to put out revisions to the sets we ship so as not to waste the processing on sets that are already well-formed. World Vector Shoreline, in particular, consisted of short chains of points that made post-projection work in Illustrator tedious. This data set has been cleaned up and turned into closed polygons throughout. In conjunction with the new generalization methods, WVS will be useful for any scale of map from 1: 250,000 to 1:1,000,000,000, with fine results.
  
  • Metric lines:
  • Small circles (both spherical and ellipsoidal)
    Rhumbs (both spherical and ellipsoidal)
    Great circles
    Ellipsoidal geodesics
    Distortion isocols (areal inflation, angular deformation, average scale)
    Tissot indicatrix specifiable at any point
    Point locations
  You will define these in text files using an XML format. You may include line style information with the definitions, in which case you can describe the characteristics of the line separately for each metric line. Or, you may simply defer to the style declared in the Line Styles dialog.
  
  • Animation cels: Specify two projections to “tween” between, and a number of cels to generate. Or, vary the parameters of a single projection. Either way, you can set Geocart off to create the imagery needed to build an animation of peerless quality. Need to stop the processing for some reason? No worries. Geocart will pick up where it left off next time. (The cels are export-only; we do not intend to render animation on-screen within Geocart in this release.)
  
  • Global Tissot indicatrix network.
  
  • New projections: Philbrick SinuMollweide and its striking interruption scheme, HEALpix, Tissot equal-area conic, Braun stereographic conic, Herschel conformal conic, Gall isographic, Lowry, James far-side perspective, Greschel, Fischer far-side perspective, general far-side perspective, Clarke twilight, and AMS lunar projections. Plus, finer control over the extruded globe projection.
  
  • UI tweaks and enhancements: Map nudging with arrows. “Revert” functionality on Macintosh. Others.

I must say, while Geocart 3 was long, long in the making, its all-new architecture is far easier to work with than the original Geocart. This bodes well for rapid improvement.

Your humble map projectionist,
~ daan Strebe

[daan]

Well. We just suffered a massive server crash. The hard drive would be a doorstop, but it’s a 2.5" thing, so, more like a door wedge. Apologies for the forums being down for a day.