Re: Zero-G and 3D starmaps
In reply to #6277 3d Format.. by Dane Johnson
Jeff Zeitlin writes, > Or, just strap on wings and fly in the empty space. I remember > reading a "kid's" SF book where one of the recreational > activities on the moon (which is hardly 0G) was just this. > Damned if I can remember the name of the book - or the author. > Just that the protagonist's boyfriend's name was "Jeff Hardesty." The short story was "The Menace from Earth", by Robert Heinlein. Dane Johnson writes: > The X-Y-Z group should maintain the "current" XXYY grouping, giving us > Terra/Solomani Rim (1827ZZ G867975-8 etc...), thus requiring little > variation on existing data and file-formats, and making the resulting data > files useable by people who want to maintain 2D orientations... I'm not sure how valuable this would be. 3D starmaps look very different from 2D ones, and the resulting trade routes and political boundaries would be quite meaningless. I've done some analysis of a near-star catalog (*), and it doesn't look as though the standard Traveller jump drive price and size hierarchy makes much sense in three-space. Now, in the Spinward Marches, there is approximately one star every other square parsec, leading to the wondrous Spinward Main. Approximately half of the stars in a 40x32x(1) parsec rectangle are reachable by jump-1, and most of the rest by jump-2. The extra jump distance mainly provides speed. On the other hand, each star has (at most) six neighbors within 1 parsec, 12 within 2, 18 within 3 and so forth. In the 25-parsec radius around Sol, there are 2250 stars in ~1750 star systems. Ignoring the possibility of drop-tanks for now, here are tables with the number of reachable systems in 'real life' and in the Solomani Rim sector in Traveller for set distances. 'Real Life' Traveller Distance Systems Distance Systems 1 0 1 0 2 4 2 all but a few 3 1027 3 all 4 1720 Breaking down the 2-3 parsec range (because with this degree of detail the numbers can be broken down any which way), 'real life' looks rather gradual: 'Real Life' Distance 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 Stars 4 88 190 299 326 561 723 842 1027 In fact, this gradual nature is more of a product of not using gridsquares rather than of using a 3D representation. But it also means that the size of your jump drives/fuel tanks also determines where you can go _at_all_ as well as how quickly you can get there to a much greater degree than in standard Traveller. A Beowulf-class Free Trader won't get much business with just Jump-1 drives, even if they do get enough fuel for two jumps! One of the reasons, for me, that 2300 feels different than Traveller is that star travel is constrained. They seem to have cunningly picked a limit of 7.7 light years ( <2.4 parsecs ) in order to give space a degree of texture that allows Terran national governments to dominate space. Perhaps also, to avoid overwhelming players with choices, which could happen given their limited display abilities... Going back to 3D Traveller, I don't think it would be very valuable to use 2D subsectors in 3D games, and vice versa. A 3D map will assume that it has six borders, not four, and will have trade routes coming in from the subsectors above and below. Furthermore, for the same number of stars, it will be of different dimensions. (more like a cube 5 parsecs on a side). If Z-coordinates are arbitrarily removed, the star systems will be in different positions, leading to different relations between them, and an entirely different political and economic situation. This also applies to the large scale boundaries of empires. Being 3-dimensional entities, they will have borders that follow the contours of their stars, rather than those of a flat map. As such, they will probably be smaller and more spherical than indicated on the standard Traveller maps. I believe that it would be a mistake to assume that 3D can be added to Traveller simply by layering subsector sheets on top of each other, because the original mapping was highly unrealistic, and many of the assumptions implicit in it are not portable. 3D Traveller sounds like fun, and I'd like to work on a universe using it. However, anything related even remotely to astrography would need to be reworked in its entireity. As such, it's unlikely to be Classic Traveller + 3D. Jack Dietz // [email removed] (*) Royal Observatory Annals number 5: Catalogue of Stars within twenty-five parsecs of the Sun (Herstmonceaux, 1970). Almost the same catalog as GDW used for the data from 2300 (Gliese 2nd Edition, also 1970). The raw data is available from arc.ames.nasa.gov, I believe, and a processed version is available for FTP somewhere. (Sorry I'm so forgetful, but I had to rebuild my filesystem recently and I've lost a lot of back mail.) - -- Jack Dietz, Southern Research Labs, Evil Geniuses for a Better Tomorrow. * Little. Yellow. Different. Sol. * [email removed], [email removed]