Tuesday, April 17, 2012

The start of making a wooden globe

I always liked globes. A few years ago I got the idea to make one out of wood and I actually started this as a project. Now I'm making a belated attempt at documenting some of this process.

Making a globe has to start with a map.  The best source I had for this was Google Maps, so I painstakingly took screenshots and merged them together to create a map of the world.

Google Maps uses a Mercator projection.  Before it can be useful as a template for making a globe, it needs to be massaged into a shape that we can trace onto a sphere.

A gore is a segment of a three-dimensional shape fabricated from a two-dimensional material.  We need to transform this Google map to look something more like this:

The gores of Waldseemüller's 1509 globe of the world

First, transform to a equirectangular projection.  I did this using a photoshop plugin called Flexify 2 which I was able to get to run under GIMP.

I found a page which has a satellite image of earth with 12 gores (as well as images for other planets), but I want political boundaries for my globe so this doesn't help.  However, that page also has a link to a perl script which can transform an image into gores.  I used this perl script to generate a map with  36 gores.

With some careful scaling, this can then be printed and traced onto the surface of a sphere using carbon paper.

1 comment:

  1. Hallo!

    Greeting from SLOVENIA! I like your project. Great work! I am doing somthing similar as you. And i have the same problem as you. Your map is the only one on the internet that is made from 36 gores. But quality of the picture is not god. Can you send me on mail your original quality picture of those 36 gores?? My mail: rok.jene.pio@gmail.com
    Or you tell me how to use perl script? I can run the program, but where the input image should be, where can you write number of gores, why the program close immediately after start(is that normal)...
    Please help me(one way ore other). Thanks!