Questions on filling IS Form 8 / 9

[samuelvss]

A few questions about filling the canonical World Grid:

Is there a canonical coordinate system for the world grid?

I am looking for a table or formula to convert world size to Hexagon Size in Kilometers.

Is there a simple automated mechanism (presumably freeware) for filling for the form? (I usually use Paint for whatever I do, and don't have time to do much.)

The only version I have is the PDF posted at:

http://www.signalgk.com/files/IS8_9.pdf

Technical, Financial, and Skill Level Constraints:
I have, with slack-jawed wonder, read some of the mapping threads that I would consider advanced. For various reasons, I'm nowhere near there, and I'm not going. At least not until I finished my [SPITS] dissertation. (Social sciences, don't you know!!) I'm doing this for occasional play with my sons, so anything more advanced than a stubby pencil impresses them; they don't get out much. So if I need to buy it, learn it, or craft it with care, it is pearls before swine...

 

[gammamutant]

((600*pi)*World Size) / 35 will give it in km

 

[samuelvss]

Thanks! So, in round numbers:

54 km * World Size = Hexagon Size in Kilometers

Anyone smart please feel free to check my math!

 

[rancke]

Is there a canonical coordinate system for the world grid?

Not officially.

I always start by assuming that the prime meridian runs down the middle of the map, separating it into two equal halves. I sometimes have hard time coming up with reasons for it, but it can also serve as an inspiration. On the map of Regina, for example, the centerline runs through some island far from the place the first colony was set up. so in the end I decided that it ran through the spot where the original survey party landed and set up camp while they searched for a good spot to place the first settlement. There's a big monument there nowadays.


Hans

 

[far-trader]

Not to dispute the answer above, just not sure where it was sourced from. Figured out perhaps? First question of course is which way are you measuring the hexes? Point to point or side to side?

Your simpler calculation is correct for the above.

For what it's worth CT Supplement 12 - Forms & Charts states the scale is determined by multiplying the world size by 146km, which is quite a difference. It doesn't say if that is point to point or side to side either.

I haven't checked to see which, if either, is actually correct or closer to the real value.

 

[far-trader]

Not officially.

I always start by assuming that the prime meridian runs down the middle of the map, separating it into two equal halves. I sometimes have hard time coming up with reasons for it, but it can also serve as an inspiration. On the map of Regina, for example, the centerline runs through some island far from the place the first colony was set up. so in the end I decided that it ran through the spot where the original survey party landed and set up camp while they searched for a good spot to place the first settlement. There's a big monument there nowadays.


Hans

I like that! Nice bit of imagination prodding

I thought I'd seen once (canon, fanon, or my own?) the prime meridian being laid on the starport.

And I recall a good looking coordinate system somewhere, but not the specifics. Might have a copy of it around here somewhere...

 

[far-trader]

OK, a quick bit of math shows gammamutant's work is the one that is off.

The S12 method is close. Multiplying world size digit by 144* would be closer if I did the math right (for hex side to side distance).

* rounded, actually 143.625, though that is also rounded, more precisely would be 143.61553 imo 144 is close enough and easier to remember

 

[gammamutant]

I counted the hexes across the equator to get 35. The formula for circumference is pi * dia. The world digit is the number of thousands of miles in diameter the world is. A kilometer is .6mi. where is the mistake?

WHOA I caught my error. I multiplied by .6 and I should have divided. My bad, sorry.

 

[far-trader]

No worries gammamutant I've done worse

 

[samuelvss]

Coordinates

Thanks, BTW, for getting the math. As to whether this is point-to-point, or side-to-side, isn't the idea behind hexes is that it's both, because they (and the whole projection) just an abstraction? If we took the hex, and broke it down into smaller hexes, it would be the same number of hexes point-to-point or side-to-side.

But for the coordinates, what is the format to express the location of a given hex. I have seen something somewhere, forgotten that, and made something else up elsewhere.

 

[BytePro]

Far-trader's 144 km matches what I use - plus or minus 71 km (i.e. taking UWP size as crude estimate). Supp 12 appears incorrect - suspect 143.6 got typed up as 146.

Side to side seems more relevant:

• On the map, that is how they are oriented on the equator
• In use, hex 'directions' point thru the sides, not the 'corners'

Sure the 'distortion' of the hexes 'squashes' the planet out of a true sphere - which, ironically, sorta represents the equatorial bulge of a planet like the earth (though a bit over exaggerated)!

As to coordinates: Recommend simply drawing normal lines on the map (an overlay would work). This could even account for the distortion on the map.

I suspect a Mega Traveller DGP book has what you are recalling in the way of a 'formula'...

 

[samuelvss]

My Solution

I have posted examples of the coordinate system I made up in my TAS Form 8-9 GIF's.

The lattitude is from a presumably canonical TAS Form 8; North is postive, South negative. To that I have added a roughly longitudinal coordinate, that labels the NW-SE hexrows alphabetically.

Thus, the Pegaton/District 268 starport is at (-2,o) in my posted example: http://www.travellerrpg.com/CotI/Gallery/index.php?n=1324

 

[Gray Pennell]

Wasn't there a method in one of the early JTAS. I cant remember the issue. errr

 

[shaunhilburn]

A few questions about filling the canonical World Grid:

Is there a canonical coordinate system for the world grid?

I am looking for a table or formula to convert world size to Hexagon Size in Kilometers.

Hexagon area sq km is approx SizDigit^2 × 16,605.6 (you can use fractional size digits)

A planet's surface area is proportional to radius squared; e.g., a planet 0.5 earth radii has a surface area 0.5^2 = 0.25 earth's.
Earth's surface area is approx. 510,065,913 sq km x 0.25 = 127,516,478 sq km. IS Form 9 contains 490 hexagons, so divide this by 490
= 260,237 sq km per hex.


On a world of size 7.76, each hex is exactly 1 million sq km.

 

[77topaz]

Is there a simple automated mechanism (presumably freeware) for filling for the form? (I usually use Paint for whatever I do, and don't have time to do much.)

You could use Hexographer.