I started something like that approach and there are a few questions about how people usually do this that came up:

Here's how it looks so far: https://i.imgur.com/9UphEZw.png

This is for a size-8 world. The middle 9 rows are straightforward, there are 40 hexes around the world for every row. I take the verticies of the hex in latitude and longitude coordinates, and scale them appropriately, and then translate them across the rows and columns for the middle part of the world. It's not quite how I pictured it, the equator is fine but the hexes start to get squished a bit at the top and bottom.

For the next row up the piecewise function should take effect, but I'm not quite sure what approach to take there - should the top verticies of the hex be scaled and the bottom ones not, so the verticies of the neighboring row line up, or do I just skip hexes every so often, in effect making a single large hex every now and then (though it's not really a hex now). The icosahedral maps in the Traveller 5 books appear to take this approach, as hexes have varying neighbor counts - the top row of the interior band has hexes with differing numbers of neighbors which makes it seem that the approach taken was to do something like this, though that doesn't maintain vertical longitude lines if translated back to the flat map. Hexes do have to be skipped as there are 40 in the center region per latitude line and 35 in the first polar latitude line.

​

​

-------- Original Message --------
 On February 14, 2018 3:16 AM, Tim <xxxxxx@little-possums.net> wrote:

>On Wed, Feb 14, 2018 at 03:33:58AM -0500, Caleuche wrote:
>>I had some difficulty coming up with a good system for translating
>> the flat traveller maps that you generate as part of the rules to a
>> sphere and started to wonder if it wouldn't be useful (in some
>> cases) when defining a world to not use hexes but points on the
>> world defined in latitudes and longitudes
>>
> The icosahedral maps can be translated very directly into latitude and
> longitude coordinates.  Latitude as just a linear function of height
> on the map.  Longitude as just a proportion of number of map tiles
> along a line of latitude (and so piecewise linear).
>
>
> - Tim
>
>The Traveller Mailing List
> Archives at http://archives.simplelists.com/tml
> Report problems to xxxxxx@simplelists.com
> To unsubscribe from this list please go to
>http://www.simplelists.com/confirm.php?u=0og3DHdoRHgL9lI7peOXYWnk6UF4c1zE
>