Showing posts with label galaxy. Show all posts
Showing posts with label galaxy. Show all posts

2013-12-21

Zoom

I made a bit of a video:


I wrote a Python script which generated Tile API URLs centered on Regina at various scales. Piped that through to curl to fill a directory with images, then used ffmpeg to assemble them. Once I had the kinks worked out it only took about 10 minutes to render.

(I used the live site rather than my development machine. If you attempt something similar, be gentle and don't request more than one image at a time!)

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2009-03-15

Galaxy Scale Mismatch

Hrm... my two sources of data for the Traveller galaxy structure don't quite equate, leading to fairly dramatic mismatches.

If you measure the Local Arm's girth at the Ray 0 i.e. through Reference (Core 0140) on the detailed map from Security Leak by Mike Mikesh, you get a distance of 1600 parsecs. If you measure the distance on the detailed map by Clifford Linehan - which he used to construct the Zhodani Core Route - you get a distance of 1760 parsecs.

Composite of the two maps.

That's about a 10% difference... and it's going to bother me. I dug a bit further and it looks like the Security Leak #5 map is the original source, per this conversation between Marc Miller and Clifford Linehan. Mr. Linehan took Mike Mikesh's original, scanned it, cleaned it up, and handed the results back to MWM who took it under the FFE fold. This would indicate that either Mr. Linehan corrected the size (to fit known dimensions of the galaxy) or accidentally scaled it up. (Charted Space doesn't quite line up either.)

Since Traveller parsecs are based on a hexagonal grid, it's actually easy to introduce an error of around 14% - hexes pack more tightly horizontally than vertically, with a ratio around 0.868. This is factored in when I map from image-space to world-space (and you'll see residue in the API). Here's a sample - the red square is precisely 10 parsecs tall, but more than 11 parsecs wide - yet it's a perfect square if you count the pixels.


If I had to guess, I'd say that one of the two galactic-scale map authors was unaware of this, and and used a horizontally-biased parsec scale for determining the number of sectors between Charted Space and the galactic core.

Bleah. :( Ω

2009-03-14

Far Out, Man!

Start at Reference in "Candy" style - and then zoom out. A lot.

Go ahead, I'll wait for you.

Nifty, huh?

Okay, if you're lazy, here's the image:


Well, I think it's nice, at any rate. This is inspired by the latest renderings of the real Milky Way galaxy, such as the one over at the Atlas of the Universe:


(Milky Way image © Richard Powell, c/o Atlas of the Universe.)

However, the TravellerMap site is a map of the Traveller galaxy, not the real Milky Way, so I had to pull out the image editor and build it from scratch. This is based on the Traveller galaxy map first introduced to the site back in 2005, courtesy of Clifford Linehan from his (now defunct?) Zhodani Core Route site, sourced by Marc Miller:


(Traveller Galaxy image © Far Future Enterprises, c/o Clifford Linehan)

There are definite differences between the real and fictional galaxy. For example, in the real Milky Way, Earth's sun is part of the Orion Arm, which is mere spur off of the Perseus Arm, next to the Sagittarius Arm. In the Traveller galaxy, Terra appears to be in the main body of a major arm. The real Milky Way is a distinctive barred spiral, whereas the Traveller galaxy is not notably barred (although I rendered a subtle bar in anyway). In a real galaxy, there are nearly as many stars in the rifts between arms as there are in the arms themselves - the arms are slowly propagating gas density waves that induce more star formation, so they are full of bright young stars. In the Traveller galaxy, the rifts have much lower density, which makes things trickier for the Zhodani core expeditions. I don't have a problem with this difference - after all, space in Traveller is 2D. I view this as a perfectly acceptable simplification for the game universe, and don't attempt to fit it to reality. To me, it's a lot like chess. Real battles between opposing armies rarely take place on a perfectly flat 8x8 grid, but that doesn't mean chess isn't a fun game that teaches real strategy.

To create the image I took the galaxy map (isolated to a white-on-black mask), the pseudorandom stars from the map site, Paint.NET and experimented with various layers, blurs, and mixing functions. The cloudy arms were created by blurring the map, rendering in clouds, then using a twist filter. This had various densities of galactic structure and stars layered on top. The core was generated with several overlapping gradients to get an overall white glow, the rosy core, and the bright bar.

If you zoom in, the "Galaxy" image will gradually fade to the "Nebula" background used for candy-style rendering (c/o Wayne Peters). The only really grody bit is that the local rifts fade in as well, and they have abrupt edges. I'm pondering what to do there. Classic Library Data states:

Situated in the center of the Imperium, Capital's astrographic location has proven of prime importance, as it controls the only gap in the Rifts for thousands of parsecs. Besides being a communications hub, Capital is a cultural center, and educational focus. - Adventure 3: Twilight's Peak (emphasis mine)
The emphasized portion is not present in Supplement 8: Library Data (A-M) and later updates of the Library Data for Capital, possibly because the Traveller universe was more refined. However, looked at on the scale of hundreds of parsecs, it is true that the Imperium - centered on Capital, does control the only large gap in the rifts... if the Great Rift and Lesser Rift are presumed to continue on for a thousand parsecs in each direction.

w00t! Google just found me an issue of Security Leak Magazine where Mike Mikesh analyzes the local rifts in the context of the overall Traveller galaxy - sweet! Well, I guess I know what I have to do next...

(EDIT 2015-10-17 - restored the galaxy bitmap to the one in use circa 2009; the blog post contained a link to the live resource which was replaced so the post had become nonsensical.)
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