Mapping Issues: Curvature, Latitude and Global Projection

A directory of geographical maps for the world of Mystara.

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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Thu Aug 21, 2008 3:35 pm

Hmm, it looks like the Master Set also has the latitudes from TM1 marked almost completely correctly based on my grid: Farend at 60N, Landfall at 40N (less sure about this one), Thyatis at 30N and the Thanegioth Archipelago at 20N. (The last two are spot on.)
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby nerik » Fri Aug 22, 2008 4:06 pm

Given that the map of Mystara was based upon a map of the Earth in the distant past (I recall a date of 100 million years ago being mentioned somewhere), whould it be helpful to obtain such a map and use it as the basis of an updated map of Mystara?
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Gawain_VIII » Fri Aug 22, 2008 4:36 pm

Geologist Dr. Chris Scotese developed the continental timeline which is considered by most geological professionals to be the most likely series of continental formations. It is this same series that predicts, several million years in the future, a new "Pangaea Ultima". His continental prediction of the Late Jurassic period (approx. 145-160 million years ago) is the closest image to our own Mystara/Urt/Known World map--and is most likely the original source. The images on Scotese's webpage are quite small--however another image, of decent size, "based on" Scotese's map can be found here.

As you can see... the Pacific Ocean is FRIGGIN' HUGE!

A very good reproduction of the original source images can be found in the TimeLife Books Planet Earth series "Continents in Collision". Unfortunately, I no longer have that series (nor the amazing Enchanted World series--I still kick myself for letting those books go!)

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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Fri Aug 22, 2008 5:05 pm

I have a book at my parents' house which has a similar map, but (as far as I remember) it is even closer to Mystara's map. It could just be a different projection, or it could be that as science has advanced in the past 30 years the maps have been made more accurate - in which case what we really would need would be an old version of the map. :D

Unfortunately I've yet to see such a map online...
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby metal » Fri Aug 22, 2008 5:25 pm

This site has a pretty good map (looks very close to Mystara)
http://www.bbm.me.uk/portsdown/PH_065_Palaeo.htm#cret

This one has even nicer maps, but the "Late Jurassic" map doesn't look like Mystara. :(
http://jan.ucc.nau.edu/~rcb7/rect_globe.html
I'm considering redrawing one of these maps to build a "homebrew" world.

Edit because I can't get the darn link to work.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby LoZompatore » Fri Aug 29, 2008 3:35 pm

At last I managed to finish my work about arranging the official maps in an unfolded icosahedron scheme. :)
See it as an attempt to keep most of the official data as it is: scale map and shape are unchanged, though latitudes and longitudes would likely be quite distorted.

As my maps are quite large and thumbnails are too blurred to be of hany help, I post them in a zipped version.

The first map shows how is it possible to unfold the icosahedron in such a way that the whole official maps are covered without cuts or rescaling. This map covers just a selection of the unfolding. The full unfolding is shown in a sketch left of the main picture.
The standard icosahedron unfolding for a spherical map is opened at N and S poles, while the belt between 30N and 30S latitudes runs unbroken in the middle of the picture. The unfolding of the picture below is basically a 60° tilting of the one above. The unbroken belt intersects the equator but its middle line is rotated 60° with respect to the equator.
A single triangle is rotated with respect to the standard (60° tilted) unfolding in order to keep the official map unbroken.
Scale is 72 miles/hex: coastlines and lakes are taken from official data. This map is 2917 kb unzipped.

http://it.geocities.com/lutetius00/Mapp ... o_72mi.zip

In the two pictures below I leave a copy of the official region covered in a 72 mi/hex scale, without any reference to the icosahedron unfolding. It is just a collection of 72 mi/hex maps. Just coastlines and lakes are shown: see if those maps can be useful for you. I did not draw the Sylvan Realm as I was not sure where to exactly place it.
The first map is 3374 kb unzipped.

http://it.geocities.com/lutetius00/Mapp ... p_72mi.zip

The map below is without hexes outside the official area. It is a lighter picture than the one above (1485 kb unzipped):

http://it.geocities.com/lutetius00/Mapp ... _clean.zip

That's all. If you hane any question or if you have some remark about the first picture please don't hesitate! ;)
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Big Mac » Mon Feb 16, 2009 12:05 am

I came to this thread from the Hollow World forum.

This is a really interesting thread, but I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.

Is Mystara supposed to look like a sphere (with a hole at either pole) or is it supposed to have dents in the poles (and look more like an apple)?

Would an apple like dent explain away any of the "mistakes" in degrees on official maps? Or have I introduced a red (or a red steel ;) ) herring?

BTW: I would really love to see all D&D worlds turned into accurate maps that could be imported into programs like Google Earth or used by artists like Silverblade to make space pictures of the planets. I do hope that when this project is finished, there will be plenty of instructions so that people with less cartography-fu can work out how to import a KW or HW map into any appropriate application. (Maybe when I give Truespace another go, I'll see if I can import the Known World into it. 8-) )
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Gawain_VIII » Mon Feb 16, 2009 6:28 am

Big Mac wrote:This is a really interesting thread, but I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.

Is Mystara supposed to look like a sphere (with a hole at either pole) or is it supposed to have dents in the poles (and look more like an apple)?

Would an apple like dent explain away any of the "mistakes" in degrees on official maps? Or have I introduced a red (or a red steel ;) ) herring?

According to cannon, the Known World (before it was labelled as Mystara) was the exactly like our R/W Earth, except that it was perfectly spherical instead of bulging at the equator, as our own planet does.

When the Hollow World boxed set came out (and all later resources followed suit) the size of the planet was drastically reduced (primarily by reducing the size of the "Pacific Ocean" and the "Sea Kingdoms" older maps had made reference to) and, naturally, made hollow. All other aspects of the planet's physical features are assumed to be the same.

So... to answer your question, the answer is "a perfect sphere" without indentation.

However, to make the matter even more confusing, we've recently learned, thanks to our many Mystaran cartographers, that there is more mapped surface area of Mystara than there is surface of Mystara to be mapped. This, with the aid of Google Earth, is where we learned of the distortion of the latitude lines. The simplest fix is simply retro-resize the outer world back to it's original R/W Earth dimensions by replacing the missing ocean (and Sea Kingdoms).

Doing that raises a new problem. If we change the outside dimension (which, btw, seems to have a majority of support amongst the Mystaran community) we either have to increase the surface area of the Hollow World (essentially doubling the size) or double the thickness of the crust in order to retain the interior surface area, subsequently making the curve of the openings even more gradual. This is where the community has yet to find consensus. Some like the prospect of having alot of "virgin territory" in the Hollow World with which to populate. Others prefer to retain the integrity of the setting by changing as little as possible.

Myself, I see the benefits of both and have not chosen a "camp". However I will play Alphak's advocate and argue in favor of the position hat seems to be loosing at the moment.

The third option, is to leave the outer surface smaller... but in my mind, that is not an option because it would require the removal of already-mapped surface areas. I have always been an advocate of "Earth-sized Mystara". I just don't know how to reconcile the HW problem.

Disclaimer: The above statements are purely my own opinion. I am not a cartogropher, geologist, or mathmetician. I do not have the technical expertise required for determining the best solution for the problems described above, nor even sure that I have described the issue accurately (but I think I've got the jist across).

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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Mon Feb 16, 2009 7:39 am

Big Mac wrote:This is a really interesting thread...


Welcome, David! I imagine that many of the issues discussed in this thread probably apply to settings other than Mystara too - because essentially all we're trying to reconcile is the original cartographers' tendency to make maps without thinking about globes, distortion, and projection.

...I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.

Is Mystara supposed to look like a sphere (with a hole at either pole) or is it supposed to have dents in the poles (and look more like an apple)?

Would an apple like dent explain away any of the "mistakes" in degrees on official maps? Or have I introduced a red (or a red steel ;) ) herring?


The consensus on this issue seems to be that Mystara is spherical or near-spherical. To be perfectly honest, I don't really know much about our planet bulging at the equator, so I tend to just ignore such things.

The confusion about polar openings is easily resolved if you look at the cross-section illustration originally provided in the Hollow World set. Unfortunately I haven't yet made a replica of it, and I can't find a scan of it anywhere online, but here's the next best thing:

Image

I think this image predates TSR's Hollow World set. It's part of the so-called "Hollow Earth Theory", upon which the Hollow World Campaign Setting seems to have been based. The reason I say this is that TSR's actual Hollow World cross-section diagram bears a very strong resemblance to this image.

In any case, for the purposes of this discussion please consider this diagram to be a pretty accurate cross-section of the world of Mystara. You can see that the 90 degrees north and 90 degrees south points - the poles - do not exist on this globe. Instead, the world curves gradually back round, forming a sort of lip, and leaving a big hole. None of this really affects the whole issue of whether or not the world is a sphere, other than the fact that the diagram certainly makes it look like one.

In any case, one of our issues is that we're not entirely sure at what latitude the lip begins, and official maps seem to be a bit contradictory on how to label the degrees from that point to 90 degrees.

If by your apple analogy you meant that there is a sort of dimple instead of the poles, then it was a good analogy (other than the not being hollow bit!).

BTW: I would really love to see all D&D worlds turned into accurate maps that could be imported into programs like Google Earth or used by artists like Silverblade to make space pictures of the planets. I do hope that when this project is finished, there will be plenty of instructions so that people with less cartography-fu can work out how to import a KW or HW map into any appropriate application. (Maybe when I give Truespace another go, I'll see if I can import the Known World into it. 8-) )


Not only is compatibility with existing tools such as Google Earth a priority, but in fact Hugin has already gone ahead and done a lot of work in that field! :) Things are somewhat complicated by the fact that we have an inner world to map too, and that none of the existing tools are likely to be very good at mapping it...

Your comments are really making me wish to see Silverblade doing some Mystara planetary artwork. :D It would be great to see some renderings of the planet from interesting angles such as looking down through the polar openings and such. (Although actually these are always covered with vast banks of clouds to keep them hidden... However now that I think about it the clouds would be lit from underneath by the central sun, so there could certainly be some interesting effects going on.)
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby metal » Mon Feb 16, 2009 8:14 am

Thorf, where did you find that image?
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Re: Mapping Issues: Curvature, Latitude and Global Projectio

Postby Thorf » Mon Feb 16, 2009 9:35 am

Gawain_VIII wrote:According to cannon, the Known World (before it was labelled as Mystara) was the exactly like our R/W Earth, except that it was perfectly spherical instead of bulging at the equator, as our own planet does.


Yeah, specifically I think the Immortal Rules Set dealt with this the most, didn't it? It even went as far as explicitly placing the Known World (=Mystara) in our own solar system, and adding a 10th planet called Damocles, destined to blow up and become what is now the asteroid field. (Of course now it would be the 9th planet, since Pluto has been demoted...)

Couple this with the fact that the Known World as featured in the Master Set (and partially in the Companion Set and modules before that) is closely based on a map of the Earth as it may have appeared millions of years ago, and we can see that it was indeed originally intended to be the same dimensions (indeed the very same planet) as our Earth.

When the Hollow World boxed set came out (and all later resources followed suit) the size of the planet was drastically reduced (primarily by reducing the size of the "Pacific Ocean" and the "Sea Kingdoms" older maps had made reference to) and, naturally, made hollow. All other aspects of the planet's physical features are assumed to be the same.


You made a good point here: "all later resources followed suit". It sounds obvious but if we are going to be changing things it can be useful to establish the source of the original changes, and then whether the products following it just used that data verbatim, adapted it, or expanded it somehow.

Anyway, another key point is that I don't think they knew they were changing the size of the world.

But most importantly, they changed the fundamental shape of the world. Partly this is due to the use of a projection (as opposed to the Master Set's rectangular, apparently distortion-free map), but in adapting the map to the projection they stretched it so that it no longer fits with the established maps - i.e. the area hex maps that most people are most familiar with.

However, to make the matter even more confusing, we've recently learned, thanks to our many Mystaran cartographers, that there is more mapped surface area of Mystara than there is surface of Mystara to be mapped. This, with the aid of Google Earth, is where we learned of the distortion of the latitude lines. The simplest fix is simply retro-resize the outer world back to it's original R/W Earth dimensions by replacing the missing ocean (and Sea Kingdoms).


This image should help in visualising the problem at hand. The icosahedron net is the enhanced projection we have come up with, and the coloured map is the old (non-projected) map that will be fit into the net. You can easily see that about half the net will end up empty.

Image

Just out of interest, this is what happens when we fit the second (projected) official version of the world map to the icosahedron net. It fits almost perfectly, but as a consequence the whole world has been stretched quite drastically horizontally.

Image

Doing that raises a new problem. If we change the outside dimension (which, btw, seems to have a majority of support amongst the Mystaran community) we either have to increase the surface area of the Hollow World (essentially doubling the size) or double the thickness of the crust in order to retain the interior surface area, subsequently making the curve of the openings even more gradual. This is where the community has yet to find consensus. Some like the prospect of having alot of "virgin territory" in the Hollow World with which to populate. Others prefer to retain the integrity of the setting by changing as little as possible.


Yep, we Mystara fans certainly know how to complicate things! :lol: As if the Outer World problem wasn't enough, we also have the Hollow World to deal with - and whatever solution we choose will obviously have to fit with both maps. The icing on the cake is that we need to work with the Master Set map for the Outer World, since that is the one that fits closely with the hex maps. But even though the Hollow World Set Outer World map is no good, we nonetheless have to work with the Hollow World map from that very same set, since it is our only source - and of course it fits with all the Hollow World hex maps.

Personally I think we have pretty much been forced to accept the thickening of the crust, because anything else will require messy rescaling or redrawing of hex maps. Additionally, the polar regions are in my opinion one of the most problematic areas already, and I'm pretty sure that all the various official maps don't add up, so we're going to have to largely redo them anyway.

Myself, I see the benefits of both and have not chosen a "camp". However I will play Alphak's advocate and argue in favor of the position hat seems to be loosing at the moment.


Agitator. :mrgreen:

The third option, is to leave the outer surface smaller... but in my mind, that is not an option because it would require the removal of already-mapped surface areas. I have always been an advocate of "Earth-sized Mystara". I just don't know how to reconcile the HW problem.


Yes, I agree. My priorities in this regard are quite simple:

  1. Large scale (1, 2, 4, 6, 8 mile per hex) maps are the most trustworthy, and supersede smaller scale maps as primary sources.
  2. Medium scale (24 and 48 mile per hex) maps are useful for lining things up when large scale maps are absent.
  3. Small scale (72 and 150 mile per hex, world and regional line-art) maps are only useful for getting vague pictures of overall terrain/coastlines, especially when nothing else is available.
  4. All efforts should be made to preserve the integrity of the large scale maps as much as possible, in regards to shape as well as scale.
  5. As much as possible, it's desirable to maintain the overall shapes shown in the small scale maps.

Put all these together and it seems the conclusions pretty much decide themselves. (Once we discover them, that is. ;) )

Disclaimer: The above statements are purely my own opinion. I am not a cartogropher, geologist, or mathmetician. I do not have the technical expertise required for determining the best solution for the problems described above, nor even sure that I have described the issue accurately (but I think I've got the gist across).


I think you were pretty much spot on, Roger! :) It's a very complex issue, and I don't think any of us have the technical expertise required to find the best solution - at least not by ourselves. But collectively we rock. :twisted:
Last edited by Thorf on Mon Jan 25, 2016 1:27 pm, edited 2 times in total.
Reason: Mixed up my polyhedrons.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Mon Feb 16, 2009 9:52 am

metal wrote:Thorf, where did you find that image?


There used to be a site all about it which used that image, but it seems to have been taken down. You can see an old version of it here, but I can't seem to find the exact page I remember.

It seems that there is a whole conspiracy theory behind the concept which dates back rather a long time. Or it may just have been a science fiction/fantasy idea, who knows. (And it's not as if there's any real difference anyway! ;) )

I think some members of our community may be aware of this already, because for example there is a Hollow Moon theory in the original concept too.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Hugin » Tue Feb 17, 2009 5:00 pm

Thorf wrote:My priorities in this regard are quite simple:

  1. Large scale (1, 2, 4, 6, 8 mile per hex) maps are the most trustworthy, and supersede smaller scale maps as primary sources.
  2. Medium scale (24 and 48 mile per hex) maps are useful for lining things up when large scale maps are absent.
  3. Small scale (72 and 150 mile per hex, world and regional line-art) maps are only useful for getting vague pictures of overall terrain/coastlines, especially when nothing else is available.
  4. All efforts should be made to preserve the integrity of the large scale maps as much as possible, in regards to shape as well as scale.
  5. As much as possible, it's desirable to maintain the overall shapes shown in the small scale maps.

Put all these together and it seems the conclusions pretty much decide themselves. (Once we discover them, that is. ;) )

This certainly the best approach to tackling this problem. If only we all had all the time we wanted to do our various projects; wouldn't that be perfect!
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby nerik » Wed Feb 25, 2009 10:59 pm

Thorf wrote:
metal wrote:Thorf, where did you find that image?


There used to be a site all about it which used that image, but it seems to have been taken down. You can see an old version of it here, but I can't seem to find the exact page I remember.


Well, I did find This. Edgar Rice Burroughs wrote a number of novels about Pellucidar, which was his take on the hollow world idea. Yes, Tarzan shows up in a few of them. IIRC there was a Tarzan TV show a few years back which featured a trip to Pellucidar, in fact, now I think of it, the Disney spin of of their animated Tarzan included a Pellucidar episode as well!

Thorf wrote:It seems that there is a whole conspiracy theory behind the concept which dates back rather a long time. Or it may just have been a science fiction/fantasy idea, who knows. (And it's not as if there's any real difference anyway! ;) )

Yup, there are people who believe this is all true, I remember reading a book by Sir Patrick Moore many (about 20) years ago which described a number of 'alternate' cosmologies that described the hollow earth theory, and I'm sure it got mentioned in The Supressed Transmission as well.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Big Mac » Sun Mar 01, 2009 3:44 am

Gawain_VIII wrote:
Big Mac wrote:This is a really interesting thread, but I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.

Is Mystara supposed to look like a sphere (with a hole at either pole) or is it supposed to have dents in the poles (and look more like an apple)?

Would an apple like dent explain away any of the "mistakes" in degrees on official maps? Or have I introduced a red (or a red steel ;) ) herring?

According to cannon, the Known World (before it was labelled as Mystara) was the exactly like our R/W Earth, except that it was perfectly spherical instead of bulging at the equator, as our own planet does.

When the Hollow World boxed set came out (and all later resources followed suit) the size of the planet was drastically reduced (primarily by reducing the size of the "Pacific Ocean" and the "Sea Kingdoms" older maps had made reference to) and, naturally, made hollow. All other aspects of the planet's physical features are assumed to be the same.

So... to answer your question, the answer is "a perfect sphere" without indentation.


Hmm. So you don't agree with Thorf's "dimples" at the polar openings?

Gawain_VIII wrote:However, to make the matter even more confusing, we've recently learned, thanks to our many Mystaran cartographers, that there is more mapped surface area of Mystara than there is surface of Mystara to be mapped. This, with the aid of Google Earth, is where we learned of the distortion of the latitude lines. The simplest fix is simply retro-resize the outer world back to it's original R/W Earth dimensions by replacing the missing ocean (and Sea Kingdoms).

Doing that raises a new problem. If we change the outside dimension (which, btw, seems to have a majority of support amongst the Mystaran community) we either have to increase the surface area of the Hollow World (essentially doubling the size) or double the thickness of the crust in order to retain the interior surface area, subsequently making the curve of the openings even more gradual. This is where the community has yet to find consensus. Some like the prospect of having alot of "virgin territory" in the Hollow World with which to populate. Others prefer to retain the integrity of the setting by changing as little as possible.


I myself, am a great believer in sticking to canon as much as possible.

Where I seriously dislike canon, I believe that (to retain integrity to a campaign setting) I should create stuff that complies with the original canon (for the official site) and then create "variant house rules" that can replace the canon. (However, I usually prefer to present canon in a new way, rather than decide it doesn't exist.)

Ultimately, any GM can change anything: rules, maps, whatever, but in order to allow fans to collaborate, you really need to have a common agreement on a setting. (Once you get the vanilla stuff done, everyone can run off and create their own variant stuff, but while the vanilla stuff remains incomplete, attempts to make material that is incompatible with canon*, just derail the central project that everyone else can spin off of.)

* = I don't know how much of this sort of thing the Mystara community gets, but people often join the Spelljammer community with plans to reinvent Spelljammer with "the phlogiston replaced by hyperspace", "Grubbian gravity replaced by Newtonian physics", "the Elven Imperial Navy replaced by Star Fleet" or some other idea that is potentially interesting, but ultimately not Spelljammer.

Gawain_VIII wrote:Myself, I see the benefits of both and have not chosen a "camp". However I will play Alphak's advocate and argue in favor of the position hat seems to be loosing at the moment.

The third option, is to leave the outer surface smaller... but in my mind, that is not an option because it would require the removal of already-mapped surface areas. I have always been an advocate of "Earth-sized Mystara". I just don't know how to reconcile the HW problem.


My personal preference with canon, is stick to it if possible, but where canon is broken make the least amount of changes possible.

The Dragonlance cosmology might be a good yardstick for deciding what to do with Mystara's size.

Back in Dragonlance Adventures (1e) Dragonlance had its own cosmology. It wasn't well documented, but the Dragonlance Chronicles novels described one of its three outer planes. During 2nd edition AD&D, Dragonlance was switched over to the Great Wheel cosmology (the Greyhawk/Planescape cosmology). The Speljammer product SJR7 Krynnspace gave Dragonlance its own planetary system.

The 3rd edition version of Dragonlance (which had a major input from the Dragonlance fans) switched away from the Great Wheel cosmology and also switched away from the Spelljammer planets. I was initially convinced that this was some sort of anti-crossover concept (i.e. dump the Planescape and Spelljammer stuff) so was initially highly suspicious of it.

But looking at the changes, a lot of them are actually fixes for things that 2e DL broke. Reading the novels convinces me that 2e Dragonlance should never have been put into the Great Wheel**. As for the changes with the planets, that did bug me more, but looking at the new set up, each god*** now gets one constellation, one moon or one planet (and all the neutral gods except two have a planet). I'm told that there is a 2nd edition Dragonlance product or a Dragonlance novel where the planets are named and match what was put into the 3rd edition DLCS.

** = It should have been put into Planescape, but not via the Great Wheel. They should have used another way to connect Sigil to the DL outer planes. (But that is another topic for another forum.)

*** = The old SJ system had a planet called Nehzmyth that is basically a joke about Bruce Nesmyth and Shinare was left without a planet.

So while I initially disagreed with the DLCS, I have looked at stuff and decided that the changes it makes are in the interest of the campaign setting.

I think that is what you lot need to do with this size thing. If I understand you: the new size would "damage" the Known World, but the original size would "damage" the Hollow World.

To me, the actual diameter of a planet is not too important. So when compared with the potential damage to the map, I say toss it out of the window.

If the later Mystara products were based on an error, then it is your "duty" to the canon to remove that one error and restore the previous (workable) size, so that the Known World maps work.

That seems to give you a problem with the Hollow World, and you seem to be torn between retaining the Hollow World size or retaining the thickness of the world.

To me it seems that both changes to the Hollow World would be a break from canon. So the important thing is to ask which is "less damaging to Mystara".

It seems to me that stretching the Hollow World maps would be disruptive to how things work, and while adding in fanon areas would be fun, if you have a total surface map, then new areas could be a unnecessary disruption to the original HW canon.

On the other hand making the "crust" (or whatever it is called) of Mystara thicker would also be a disruption to the original HW canon.

How many adventures deal with travel through the planet surface? How many products deal with the Mystaran underdark? How many products would actually be "damaged" if you put the KW surface at the original (RW Earth) size and put the HW surface at the later HW size and let the crust "soak up" TSR's "continuity error"?

I'm pretty sure there were a fair number of Hollow World products. If there were a lot less "underdark" products, I'd probably side with keeping Hollow World constant and "screwing around" with the underdark. (And if Mystara doesn't have any underdark products, I wouldn't even spend a second of regret - I'd just boost up the thickness of the crust or make the World Shield thicker.)
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Big Mac » Sun Mar 01, 2009 4:52 am

Thorf wrote:
Big Mac wrote:This is a really interesting thread...


Welcome, David! I imagine that many of the issues discussed in this thread probably apply to settings other than Mystara too - because essentially all we're trying to reconcile is the original cartographers' tendency to make maps without thinking about globes, distortion, and projection.


Thanks for the welcome, Thorf!

Spelljammer* is a setting of thousands of worlds, yet each planet gets far less detail than even the Hollow World setting added to Mystara. So as a SJ fan, any work you do here is of a lot of interest to me. But as someone interested in cartography maps of all TSR's gameworlds are very interesting to me.

* = One thing that is either cool or annoying about Spelljammer, is that (like Planescape) it was designed to double up as a transitive setting and allow GMs to connect other gameworlds together. So while a FR fan might want to raid Mystara canon for their FR game, a SJ fan would rather see Mystara thrive and then build a Mystaraspace around it.

I wasn't really a fan of the old hex maps, but the new maps (that look more like real world maps) really help me bring TSR's worlds to life in my head. Even if I never get to play in a Mystara game, I'd love to have a large laminated map of Mystara's Outer World and a large laminated map of Mystara's Hollow World for my collection.

Thorf wrote:
Big Mac wrote:...I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.

Is Mystara supposed to look like a sphere (with a hole at either pole) or is it supposed to have dents in the poles (and look more like an apple)?

Would an apple like dent explain away any of the "mistakes" in degrees on official maps? Or have I introduced a red (or a red steel ;) ) herring?


The consensus on this issue seems to be that Mystara is spherical or near-spherical. To be perfectly honest, I don't really know much about our planet bulging at the equator, so I tend to just ignore such things.


Well, if the argument for Mystara being Earth-sized is based on it being "the same as the Earth" then you need to look this up. Either you are going to use the diameter across the equator as the diameter of Mystara or use the diameter from pole-to-pole as the diameter of Mystara. Or take an average. Or some sort of thing like that.

My un-scientific understanding of the bulge at the equator is that gravity is the same on both the poles and the equator, but the equator is turning quickly (at 1 revolution per day) and this causes centripetal** force that balances out some of the force of gravity. By the same principle, you should be slightly lighter and slightly taller when you stand on the equator.

** = Centrifugal force is nonsense, by the way. Things do not fling outwards, they carry on travelling in a straight line. However, I'd be tempted to use centrifugal force for Spelljammer (or D&D in general) because SJ uses so many other disprooved scientific theories that adding in another bit of faulty logic seems to be the way to expand SJ.

When it comes to Mystara, I'd ignore science and say that the World Shield is creating uniform gravity. It is far more simple to have a sphere (with any appropriate distortions around the polar openings) so I'd say that trying to be scientifically accurate would be a mistake. Scientific accuracy*** will complicate your 3D planetary model and add zilch to the GM's ability to run a good game.

*** = I occasionally have debates with people who want to replace the wonky "laws of nature" that Spelljammer has with real-world physics. I can't think of a single proposed change to SJ canon that didn't unzip an important part of the background and make the GM have a bunch of work keeping the universe working.

Thorf wrote:The confusion about polar openings is easily resolved if you look at the cross-section illustration originally provided in the Hollow World set. Unfortunately I haven't yet made a replica of it, and I can't find a scan of it anywhere online, but here's the next best thing:

Image


I love that image. I knew that I'd had a deja vous feeling the first time I'd seen the Hollow World boxed set, but couldn't recal where I had seen it before!

BTW: You should really provide a like back to Flickr's image page, when you grab their images. It helps people search for related stuff. And it is also in their terms and conditions (they could get narky, one day, and delete your account :o ).

Thorf wrote:I think this image predates TSR's Hollow World set. It's part of the so-called "Hollow Earth Theory", upon which the Hollow World Campaign Setting seems to have been based. The reason I say this is that TSR's actual Hollow World cross-section diagram bears a very strong resemblance to this image.


The pseudoscientific theory of a Hollow Earth, with open poles, seems to date back to 1818. This is one of two models that you can see on Wikipedia (in a more simplified form). The earlier (1692) theory doesn't have open poles and has concentric spheres.

Edgar Rice Burrows was writing novels about Pellucidar back in 1914 and some of those may have been inspiration for TSR's Hollow World material.

Thorf wrote:In any case, for the purposes of this discussion please consider this diagram to be a pretty accurate cross-section of the world of Mystara. You can see that the 90 degrees north and 90 degrees south points - the poles - do not exist on this globe. Instead, the world curves gradually back round, forming a sort of lip, and leaving a big hole. None of this really affects the whole issue of whether or not the world is a sphere, other than the fact that the diagram certainly makes it look like one.

In any case, one of our issues is that we're not entirely sure at what latitude the lip begins, and official maps seem to be a bit contradictory on how to label the degrees from that point to 90 degrees.


Hmm. You are going to get a mapping problem if the lip is curved. Slice the map along the World shield and "iron it out" and the geography would get a lot closer to the poles than it actually is. You are going to get the false impression, that you are closer to due north than you actually are. I think that claiming you can get to 90 degrees is probably a little bit steep, but you might add in a couple of extra degrees and get to 85 instead of 80 (or 89 instead of 87 or whatever). It might be interesting for someone to measure the distances and say how much "extra land" is getting created.

Thorf wrote:If by your apple analogy you meant that there is a sort of dimple instead of the poles, then it was a good analogy (other than the not being hollow bit!).


Yep. Dimple. That is what I was looking for. A dimple on the outside and a second dimple on the inside (i.e. the Hollow World could dimple outwards towards the World Shield).

I don't know if dimples could help fix the map. And if you had dimples, I don't know how you would measure the "false northwards" that would happen after the planet curves away from the pole and towards the World Shield.

Thorf wrote:
Big Mac wrote:BTW: I would really love to see all D&D worlds turned into accurate maps that could be imported into programs like Google Earth or used by artists like Silverblade to make space pictures of the planets. I do hope that when this project is finished, there will be plenty of instructions so that people with less cartography-fu can work out how to import a KW or HW map into any appropriate application. (Maybe when I give Truespace another go, I'll see if I can import the Known World into it. 8-) )


Not only is compatibility with existing tools such as Google Earth a priority, but in fact Hugin has already gone ahead and done a lot of work in that field! :) Things are somewhat complicated by the fact that we have an inner world to map too, and that none of the existing tools are likely to be very good at mapping it...


I'm not sure if it was him who said it, but I think Silverblade said this was possible.

If the normal mapping tools didn't do this, you could just look for tools designed to create dyson sphere's for science fiction. Essentially, the Hollow World is a fantasy version of a dyson sphere, so they should work.

Thorf wrote:Your comments are really making me wish to see Silverblade doing some Mystara planetary artwork. :D It would be great to see some renderings of the planet from interesting angles such as looking down through the polar openings and such. (Although actually these are always covered with vast banks of clouds to keep them hidden... However now that I think about it the clouds would be lit from underneath by the central sun, so there could certainly be some interesting effects going on.)


If I could clone Silverblade, I'd love to see him make models of every D&D world and have a big poster where I can see all of them alongside each other. Sadly most of the D&D worlds are not properly mapped. Ironically, your project might actually turn out the first 100 percent surface map. So you might be able to help him. :D

If you surf around his website you will see that occasionally (mostly with the Spelljammer images) he has turned objects into glass, so that you can see how inner details work. So if he (or someone else) made a 3D model of Mystara, he could probably recycle the same model to make a cross-section diagram that showed how thick the crust was and where the inner sun was.

BTW: He can do animation too. A rotating Mystara would take longer to render, but would be possible.

What I would really love to see, would be a space voyage into Mystaran orbit, and then through the pole into the Hollow World. :mrgreen:

Trouble is most Mystara fans want to use non-SJ ships. It takes Silverblade eons to build ships, so even if you could get him accurate deck plans of the Princess Arc, he would need to spend ages getting it right****.

**** = If you think getting maps to work is fun, you should have a chat to Silverblade about the vertical errors that TSR put into its two dimensional SJ deck plans. A lot of these errors make 3D versions of the original ships totally impossible (or make a 3D model look nothing like the ship illustrations that come with the deck plans). And with Grubbian-gravity forming a plane through the middle of a SJ ship, every ship has flipped lower decks and you get the same sort of errors that prevent the Hollow World lining up with the Outer World. It seems you have one planet-sized error and we have dozens of ship-sized errors. :lol:
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Big Mac » Sun Mar 01, 2009 4:57 am

Big Mac wrote:Trouble is most Mystara fans want to use non-SJ ships. It takes Silverblade eons to build ships, so even if you could get him accurate deck plans of the Princess Arc, he would need to spend ages getting it right.


Talking of deck plans for the Princess Arc, is this sort of thing, and dungeon and building maps, ever going to be part of your project, or are you strictly focusing on the big maps?
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Sun Mar 01, 2009 9:09 am

Big Mac wrote:
Gawain_VIII wrote:So... to answer your question, the answer is "a perfect sphere" without indentation.


Hmm. So you don't agree with Thorf's "dimples" at the polar openings?


I'm pretty sure we both agree, actually, because we're all working from the same diagrams and maps of Mystara, which make it pretty clear. The form and dimensions of the polar openings are also covered in detail by official maps. The only possible point of contention really is whether Mystara is perfectly spherical, or ever-so-slightly bulged like the real world.

I looked into this bulging on Wikipedia, and it seems really pretty inconsequential:

[table][tr][th]Equatorial radius[/th][th]Polar radius[/th][th]Mean radius[/th][/tr]
[tr][td]6,378.1 km[/td][td]6,356.8 km[/td][td]6,371.0 km[/td][/tr][/table]

(Yay, my first table! It's just like HTML so not that hard to do manually. ;) )

That's not a lot of variation - so little, in fact, that I think we can safely ignore any effect it might have on maps.

I myself, am a great believer in sticking to canon as much as possible.

Where I seriously dislike canon, I believe that (to retain integrity to a campaign setting) I should create stuff that complies with the original canon (for the official site) and then create "variant house rules" that can replace the canon. (However, I usually prefer to present canon in a new way, rather than decide it doesn't exist.)

Ultimately, any GM can change anything: rules, maps, whatever, but in order to allow fans to collaborate, you really need to have a common agreement on a setting. (Once you get the vanilla stuff done, everyone can run off and create their own variant stuff, but while the vanilla stuff remains incomplete, attempts to make material that is incompatible with canon*, just derail the central project that everyone else can spin off of.)


Yep, the point of sticking with official info as much as possible is that it makes your work more usable by the community. Original ideas are great, but if they violate someone's perceived "spirit" of the world, or worse if they remake the world, the number of people interested will be a lot less.

This is why you will be unsurprised to hear that my Atlas project has staying official as much as possible as one of its primary aims. Currently I'm still working through official source material, but at some point I'm going to begin development on new areas, as well as using fan-made sources. I have already outlined my policy for this, which is to go as far as possible using official sources and release the results before going ahead and developing new stuff. This way, people who don't like the way I (or my sources) have developed a region will still be able to use my base-maps to develop their own version a lot more easily.

* = I don't know how much of this sort of thing the Mystara community gets, but people often join the Spelljammer community with plans to reinvent Spelljammer with "the phlogiston replaced by hyperspace", "Grubbian gravity replaced by Newtonian physics", "the Elven Imperial Navy replaced by Star Fleet" or some other idea that is potentially interesting, but ultimately not Spelljammer.


This does happen, and we do have people in the community who like this kind of redevelopment. I don't have anything against them, but personally I'm not interested in that kind of thing unless it's done deliberately and explicitly as an alternate world type thing. I tend to be put off when the first glaring difference with my view of Mystara comes up.

That said, we all have different ways of doing things and I won't complain just because someone posted something that I'm not going to read. ;)

My personal preference with canon, is stick to it if possible, but where canon is broken make the least amount of changes possible.


Yep, that's the plan. In this case it comes down to what to sacrifice to keep the most important things intact while resolving the problems TSR's cartographers left for us.

<snip> <snip> <snip>

To me it seems that both changes to the Hollow World would be a break from canon. So the important thing is to ask which is "less damaging to Mystara".

It seems to me that stretching the Hollow World maps would be disruptive to how things work, and while adding in fanon areas would be fun, if you have a total surface map, then new areas could be a unnecessary disruption to the original HW canon.

On the other hand making the "crust" (or whatever it is called) of Mystara thicker would also be a disruption to the original HW canon.

How many adventures deal with travel through the planet surface? How many products deal with the Mystaran underdark? How many products would actually be "damaged" if you put the KW surface at the original (RW Earth) size and put the HW surface at the later HW size and let the crust "soak up" TSR's "continuity error"?

I'm pretty sure there were a fair number of Hollow World products. If there were a lot less "underdark" products, I'd probably side with keeping Hollow World constant and "screwing around" with the underdark. (And if Mystara doesn't have any underdark products, I wouldn't even spend a second of regret - I'd just boost up the thickness of the crust or make the World Shield thicker.)


I mostly agree with your analysis. The simple answer is that the crust doesn't matter. The official version has it 1200 miles thick. That's way more depth than any setting could possibly ever productively use, and we're in general agreement that the deepest official culture (the Shadow Elf Territories) is at about 6000 feet below the ground.

There are quite a few officially detailed ways to traverse the planet's crust and get to the Hollow World, but most involve magic (such as Atruaghin's Mystic Conveyer, which is essentially a lift between the Outer and Hollow Worlds), and as such the increased depth is unlikely to cause problems.

Simply put, increasing the depth of the crust is so near irrelevant that it's an easy choice - especially when compared with the other choices we have to rectify these mapping mistakes.

Big Mac wrote:Spelljammer* is a setting of thousands of worlds, yet each planet gets far less detail than even the Hollow World setting added to Mystara. So as a SJ fan, any work you do here is of a lot of interest to me. But as someone interested in cartography maps of all TSR's gameworlds are very interesting to me.


Great! I'm happy if our mapping efforts are going to be of use to you in some way. :) And it's also great to have you here to do some objective criticism for us. (It has nothing to do with getting you interested in Mystara. Really! :twisted: )

I wasn't really a fan of the old hex maps, but the new maps (that look more like real world maps) really help me bring TSR's worlds to life in my head. Even if I never get to play in a Mystara game, I'd love to have a large laminated map of Mystara's Outer World and a large laminated map of Mystara's Hollow World for my collection.


Havard is the king of pretty non-hex maps so far, and LoZompatore is the hands down winner for useful and insightful maps. I'm specialising in hex maps because they're a lot easier to do (and I love them :D ), but eventually my project is scheduled to include more modern/realistic looking maps too. Since my hex maps are all vector graphics, I will be using the same base elements for both types of map. :)

Thorf wrote:
Big Mac wrote:...I've been a bit confused by the talk of the polar openings being beyond 90 degrees and by talk of distortion at the lips of the openings.


The consensus on this issue seems to be that Mystara is spherical or near-spherical. To be perfectly honest, I don't really know much about our planet bulging at the equator, so I tend to just ignore such things.


When it comes to Mystara, I'd ignore science and say that the World Shield is creating uniform gravity. It is far more simple to have a sphere (with any appropriate distortions around the polar openings) so I'd say that trying to be scientifically accurate would be a mistake. Scientific accuracy*** will complicate your 3D planetary model and add zilch to the GM's ability to run a good game.


Yep, this is exactly what I intend to do.

Regarding the polar openings, I think you're getting confused by the degrees thing. Here's how things are: the world map shows a normal projection with latitudes all the way up to 90 degrees, even though the existence of the polar openings means that the land curves inwards before it reaches the 90 degree point on a perfect sphere. To compound the problem, we don't know the exact latitude at which the curve begins (although we can have a pretty good guess). And yet they marked the northernmost point on the Outer and Hollow Worlds as 90 degrees.

What this means is that the land from 60 degrees north to 90 degrees north is not marked using the same degree notation as the rest of the planet. Instead, each of these thirty degrees are less than a real degree. And then the actual land on the curve ends up between Outer World 90 degrees and Hollow World 90 degrees!

It's weird, but that's how they did it.

I love that image. I knew that I'd had a deja vous feeling the first time I'd seen the Hollow World boxed set, but couldn't recal where I had seen it before!

BTW: You should really provide a like back to Flickr's image page, when you grab their images. It helps people search for related stuff. And it is also in their terms and conditions (they could get narky, one day, and delete your account :o ).


It's not my Flickr account I'm linking to... I just used the "link to this page" link that Flickr provided. What sort of link should I add?

The pseudoscientific theory of a Hollow Earth, with open poles, seems to date back to 1818. This is one of two models that you can see on Wikipedia (in a more simplified form). The earlier (1692) theory doesn't have open poles and has concentric spheres.

Edgar Rice Burrows was writing novels about Pellucidar back in 1914 and some of those may have been inspiration for TSR's Hollow World material.


This is interesting - thanks for the info. :) But let's get back to the subject at hand - I don't want to derail my own thread! ;)

Hmm. You are going to get a mapping problem if the lip is curved. Slice the map along the World shield and "iron it out" and the geography would get a lot closer to the poles than it actually is. You are going to get the false impression, that you are closer to due north than you actually are. I think that claiming you can get to 90 degrees is probably a little bit steep, but you might add in a couple of extra degrees and get to 85 instead of 80 (or 89 instead of 87 or whatever). It might be interesting for someone to measure the distances and say how much "extra land" is getting created.


I'm not entirely sure what you're saying here - that a compass is going to act weird when you're on the curve between the worlds, perhaps?

In any case, this is how things were officially defined, so there's really nothing to discuss about the nature of the polar openings - other than working out how they're supposed to be, and possibly adjusting their size if we need to due to making the crust wider.

I'm not sure if it was him who said it, but I think Silverblade said this was possible.

If the normal mapping tools didn't do this, you could just look for tools designed to create dyson sphere's for science fiction. Essentially, the Hollow World is a fantasy version of a dyson sphere, so they should work.


Very true! In any case it's still a pipe dream at this point. We need to get the map sorted out before we can work on anything like that.

If I could clone Silverblade, I'd love to see him make models of every D&D world and have a big poster where I can see all of them alongside each other. Sadly most of the D&D worlds are not properly mapped. Ironically, your project might actually turn out the first 100 percent surface map. So you might be able to help him. :D


That would be great! I'm definitely aiming for 100 percent coverage, but remember that Mystara technically needs 200%. ;) It's taking a while.

What I would really love to see, would be a space voyage into Mystaran orbit, and then through the pole into the Hollow World. :mrgreen:


Yeah, that would be great. Putting together a model with all the right textures would presumably be the hard part, after which it should be reasonably simple to render it from a bunch of different angles.

Trouble is most Mystara fans want to use non-SJ ships. It takes Silverblade eons to build ships, so even if you could get him accurate deck plans of the Princess Arc, he would need to spend ages getting it right****.


Yeah... Mystaran airships tend to look just like sailing ships, mostly. I can imagine how that could pose some problems, although it also means that existing models of sailing ships could be used if Silverblade has any. Of course there are specialised ships too, such as the Princess Ark (specialised is an understatement in its case...), Heldannic Warbirds, and so on.

I can only imagine the fun there must be from working with TSR's deck plans... ;)

Talking of deck plans for the Princess Arc, is this sort of thing, and dungeon and building maps, ever going to be part of your project, or are you strictly focusing on the big maps?


Building maps are already included in the plan, although geographical maps takes priority, and there is so much to do with them that to be realistic I may never get around to them. Dungeon maps, deck plans, and other stuff are a distant third.

So yes but not any time even vaguely soon.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Big Mac » Sun Mar 15, 2009 10:08 pm

I'll be replying to the above post when I have a while (probably at least three hours) to spare, but wanted to give you the heads up on an interesting thread in the Spelljammer forum: OT: improving my space art ;)

This is a thread by Silverblade, he has just made a tutorial about how to use Vue to turn a map into 3D picture of a world.

He has used high resolution images from NASA for his tutorial, but I'm sure the exact same thing could be done with a fantasy world.

Obviously the polar openings would be the big change from a conventional planet. And, I personally wonder if (despite any cloud cover over the poles) the inner sun might cause a bit of an inner glow to be visible from space. :?

But if anyone is planning on making any space art for Mystara, I'd suggest surfing over to Silverblade's thread and having a look at his Vue tutorial.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Sat Mar 28, 2009 7:36 pm

LoZompatore wrote:At last I managed to finish my work about arranging the official maps in an unfolded icosahedron scheme. :)
See it as an attempt to keep most of the official data as it is: scale map and shape are unchanged, though latitudes and longitudes would likely be quite distorted.


Can it be that I never replied to this amazing post?!? :o :shock: :oops: :| I'm so sorry, Michele! :(

The first map shows how is it possible to unfold the icosahedron in such a way that the whole official maps are covered without cuts or rescaling. This map covers just a selection of the unfolding. The full unfolding is shown in a sketch left of the main picture.
The standard icosahedron unfolding for a spherical map is opened at N and S poles, while the belt between 30N and 30S latitudes runs unbroken in the middle of the picture. The unfolding of the picture below is basically a 60° tilting of the one above. The unbroken belt intersects the equator but its middle line is rotated 60° with respect to the equator.
A single triangle is rotated with respect to the standard (60° tilted) unfolding in order to keep the official map unbroken.
Scale is 72 miles/hex: coastlines and lakes are taken from official data. This map is 2917 kb unzipped.


Wow! That's really quite impressive. I'm not entirely sure how easy it's going to be to calculate the rest of the world with this net, but I'm sure it can be done with some effort. :)

The only potential problem I can see is that the surrounding sections of the world might be warped quite badly in order to avoid warping the official hex map areas at all. I'm not really sure, we'll just have to try it and see. The advantage with keeping the icosahedral net horizontal is that only the north and south regions of the planet will be warped - and those regions are (by and large) the least developed. Moreover, they include the polar openings, which effectively means we're hiding the worst distortion in the empty space of the polar holes.

This is not to say that I disagree with the idea of not warping the hex mapped areas. But perhaps it would be good to see what sort of distortion we're looking at before deciding on such a radical (but brilliant) rethink as this.

In the two pictures below I leave a copy of the official region covered in a 72 mi/hex scale, without any reference to the icosahedron unfolding. It is just a collection of 72 mi/hex maps. Just coastlines and lakes are shown: see if those maps can be useful for you. I did not draw the Sylvan Realm as I was not sure where to exactly place it.
The first map is 3374 kb unzipped.


That's a very nice composite map. Do you by any chance have it in vector format? :geek: Actually, what programs do you use for your mapping anyway? I keep meaning to ask you. (In fact I may have asked you already in the past... :oops: )

Now, the reason why I came to this thread and realised that I hadn't replied to your message was that I think I've found a tool that can be very helpful for our efforts. :D :ugeek:

While our discussions have come very close to solving the problems with the Outer World, since last year I have been very worried about the fate of the Hollow World. Specifically, I have been trying to work out how exactly we are going to change the projection of the only existing world map to allow the remaining areas to be developed. Working on Geoff's map of Selhomarr on Suridal only made me worry even more, because the outer regions of that map are the most warped of all.

Well, my worries are almost over. :D

Here's a little preview... First, take the Suridal part of the Hollow World map. As you can see, I've added extra lines of latitude; you can see lines for every ten degrees in addition to the 0, -30, -60 and -90 lines. I'll explain why that is in a moment.

Image

The next step is to add control points to the map. We can define these control points as latitude and longitude coordinates, while will allow us to map them onto a different projection.

Image

Each of the coordinates marked in this image is a control point, telling the program the correct latitude and longitude of that particular point.

Here's what happens if you just use the intersections from the official map (which is to say only 19 of the 50 or so coordinates marked on the image above):

Image

You can clearly see that although the control points are all in the right places, the points in between still curve quite badly. In order to fix this we need to add more control points. Here's how it came out after I added more control points, including extra ones in the far south where the warping is worst:

Image

Pretty great, isn't it? 8-) :D :geek: This is what Suridal is supposed to look like!! Of course the southern part is actually more squashed horizontally, but the north-south aspect is fixed at last.

Unfortunately this will mean revising Geoff's maps, but I think it's worth it in the long run.

Right now I'm working on a map with extra longitude lines too, so that I can make it as accurate as possible. I may not add all of the control points to the whole map, though, because there are just over 700 of them altogether! Using them in the outermost portions of the map will help to solve the warping problems there, while the inner parts don't really need that much control.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Sat Mar 28, 2009 8:45 pm

Reading over this page again, I couldn't help but think...

Gawain_VIII wrote:Geologist Dr. Chris Scotese developed the continental timeline which is considered by most geological professionals to be the most likely series of continental formations. It is this same series that predicts, several million years in the future, a new "Pangaea Ultima". His continental prediction of the Late Jurassic period (approx. 145-160 million years ago) is the closest image to our own Mystara/Urt/Known World map--and is most likely the original source. The images on Scotese's webpage are quite small--however another image, of decent size, "based on" Scotese's map can be found here.

As you can see... the Pacific Ocean is FRIGGIN' HUGE!


This point about the ocean being huge is very interesting. It sort of confirms our idea that the Master Set map should indeed be extended with ocean rather than stretched to fill the missing space - it's supposed to be a huge ocean.

I wonder how the Hollow World set Outer World map would look if it were reprojected. I'm pretty sure it has been stretched quite significantly so that the land takes up the whole world instead of leaving lots of empty blue space, but it would be interesting to see. I'll have to do a de-warping of that map too, although the time it takes to plot control points will probably mean I just do a rough version (it doesn't seem worth spending all that much time on it after all).
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Sun Mar 29, 2009 8:26 am

So here it is - the Hollow World in the same type of projection as the Master Set Outer World map.

Here's what I did:

First, I added longitude lines every 10 degrees in addition to the latitude lines I put on earlier. So the whole world has a 10 degree squared grid (or graticule in cartography terms) over it.

Image

The next step was to mark control points on every single intersection of latitude and longitude lines.

Image

It probably took me a good two hours to mark all 703 control points, but the results speak for themselves. I mapped the control points to another image which is nothing more than a grid with the same control points marked, and it converted the Hollow World from the Robinson projection we're all so used to into a Latitude/Longitude projection (which is just all the info put into a regular grid of squares).

Image

Quite surprising how the distortions unfold, don't you think? I never realised Iciria was quite the shape it appears here.

Incidentally, this is by no means the end of the story as far as projections go. Now that I have all these control points set and pinned down to a known projection, it's possible to convert the map into any other projection! :D

The next step is to make a vector map of this (probably in Illustrator), and then try to adapt it to the icosaderal projection. It may be possible to do this automatically or semi-automatically, but I'm not sure yet - icosahedral projections are not standard, so it's not listed as one of the possible projections.

At worst, I will have to manually cut the world into sections and warp each one individually, but the point is that this program will allow me to do that much more accurately than Illustrator can.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Ashtagon » Sun Mar 29, 2009 4:50 pm

Awsome work, as usual :)

This makes me curious what the outer world version would look like. It might give us an idea of exactly how much horizontal stretching took place if this were done for the OW map too.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Thorf » Sun Mar 29, 2009 5:57 pm

Ashtagon wrote:Awsome work, as usual :)

This makes me curious what the outer world version would look like. It might give us an idea of exactly how much horizontal stretching took place if this were done for the OW map too.


Hehe. I could easily do a rough version, since we don't need it to be nearly as detailed as the Hollow World map.

Another map I will definitely be doing is the preapocalyptic outer world map. LoZompatore already did a detailed study on the pre-Great Rain of Fire world, but it will still be interesting to see what the official take is like unwarped. That map is also likely stretched quite badly, so it will need to be compressed to fit with the smaller Master Set version of the world.

On a related issue, it just occurred to me that perhaps there will be less need for squashing of the polar regions when fitting the Master Set map into the icosahedral net, because the map is smaller than we thought, and the massive Far End Ocean will be able to absorb some of that.
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Re: Mapping Issues: Curvature, Latitude and Global Projection

Postby Cthulhudrew » Sun Mar 29, 2009 8:47 pm

I'm not sure I'm understanding what you're doing here exactly, at least in regards to the Hollow World. Are you warping the maps to match the way they'd fit if they were on the inside of a sphere, or as they'd appear due to curvature on the outside of a sphere (as the Outer World would)?
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