How many people here are good at making polar maps?

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Big Mac
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How many people here are good at making polar maps?

Post by Big Mac » Mon Nov 17, 2014 3:49 pm

One thing I asked about over at the Kickstarter (and it isn't going to be an initial feature) was some sort of tools to help deal with the problem of making global maps with poles that are not "broken".

Quite a lot of people I've seen over the years (including professionals) do not seem to realise that the entire width of the top and bottom of a rectangular map represent a single point at the north pole and south pole of a planet.

The mistake that people seem to make is to think that they can make an "island" that does not stretch all the way across the top or bottom of the map. (And if that is wrapped onto a sphere, it looks a bit like PacMan).

I've got a friend, called Thorfinn Tait, who uses some software called G.Projector, to create different projections that allow him to view a planet from another angle. But it seems a bit of a fiddly process.

Does anyone here have any other methods for making a north pole or south pole that looks right?
David "Big Mac" Shepheard
(A Spelljammer fan hoping to user Other World Mapper to make lots of maps of planets.)
You can see more of me over at The Piazza campaign settings forums

stefanstr
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Re: How many people here are good at making polar maps?

Post by stefanstr » Mon Nov 17, 2014 4:40 pm

The only thing I could think about that does this right is this online tool: http://davidson16807.github.io/tectonics.js/

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Re: How many people here are good at making polar maps?

Post by Big Mac » Tue Nov 18, 2014 7:31 am

stefanstr wrote:The only thing I could think about that does this right is this online tool: http://davidson16807.github.io/tectonics.js/
Here is a discussion (over at The Piazza) where I was talking about the cartography tutorial put up by Thorfin Tait. Thorf goes into some detail about how to use G.Projector.

I've read the tutorial a few times, and understand the general principle, but have never actually tried to do this.
David "Big Mac" Shepheard
(A Spelljammer fan hoping to user Other World Mapper to make lots of maps of planets.)
You can see more of me over at The Piazza campaign settings forums

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Re: How many people here are good at making polar maps?

Post by gareth_w » Wed Nov 19, 2014 5:14 pm

This is a good discussion, as the major world I'm working on at the moment is a polar/scandinavian setting.

What I have used in the past is a dodecahedron "net" template to work out how regional boundaries would fit together. How that would translate into a software program I don't know. I've used a program in the past that allowed you to render your flat world to a sphere (can't remember which, sorry), but that still doesn't help the design.

OWM from the video seems to be an island/continent/land mass tool - thats what we've been shown so far, but that doesn't mean that's where the limits are. Using it as a full world design tool - is it in or out of scope? or is that a v2 thing? Don't know yet; would be interesting to find out.

The only thing I can think of that might help in software is some sort of variable grid lines, so as you move toward or away from the equator the grid lines move to compensate.

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Re: How many people here are good at making polar maps?

Post by Big Mac » Thu Nov 20, 2014 8:06 pm

gareth_w wrote:This is a good discussion, as the major world I'm working on at the moment is a polar/scandinavian setting.

What I have used in the past is a dodecahedron "net" template to work out how regional boundaries would fit together. How that would translate into a software program I don't know. I've used a program in the past that allowed you to render your flat world to a sphere (can't remember which, sorry), but that still doesn't help the design.
It sounds like you are just ahead of me, in this area.
gareth_w wrote:OWM from the video seems to be an island/continent/land mass tool - thats what we've been shown so far, but that doesn't mean that's where the limits are. Using it as a full world design tool - is it in or out of scope? or is that a v2 thing? Don't know yet; would be interesting to find out.
I'm guessing that you could probably ignore the main bulk of the planet and design your polar region with the pole in the dead centre of the map. That should allow you to use OWM (or any other tool) to create a polar continent that is the exact shape you need. But I'm not sure how you could then shunt that data up to become a strip at the top of a rectangular projection (aside from following Thorf's G.Projector technique).

I had a chat with one of the OWM staff about this sort of thing in the replies to Update #4: Almost at 70% and more features
Other World Mapper at Kickstarter wrote:
David Shepheard at Kickstarter wrote:Re: "If you have a type of map you'd like to see, let us know!"

How well is Other World Mapper able to prepare entire planet surface maps?

(I'm told that these maps need to be 1:2 ratio to wrap correctly around a sphere.)
@David Look at the third stretch goal. We're introducing meridians and parallel's from projections other than equirectangular. With Mercator, Elliptical, Gauss conformal (maybe others) meridians and parallels it would be easier to keep track of the ratios as you try to make an entire planet surface map.

We have other features planned, but that's for other stretch goals (or later updates to the software).
So it looks like global maps are going to be supported. But, having previously seen (in the Spelljammer community) that there was an issue with TSR cartographers not being able to get poles right, I asked a bit more:
Other World Mapper wrote:
David Shepheard at Kickstarter wrote:Those features sound great.

I wonder if you will be able to provide any sort of tools to help people avoid breaking the poles of spherical planets. Me and my RPG friends have found a lot of *professional* maps, that have poles that do not work.

Here is a post where a friend has faithfully copied a map of a Spelljammer world called Comporellon:
http://www.thepiazza.org.uk/bb/viewtopic.php?f=2&t=3216&start=50#p48087

The island on the South Pole (called Southcap by the TSR cartographer who designed the original map) is just not going to wrap onto a sphere properly. Instead the south pole is going to look like Pac Man. (My friend at The Piazza knows this. We were going to attempt to correct the mistake later on.)

And here is another thread showing how Anna Meyer is trying to get the poles of Oerth to work properly:
http://www.thepiazza.org.uk/bb/viewtopic.php?f=11&t=12474

Thorfinn Tait (who is as well known in the Mystara community as Anna Meyer is in the Greyhawk community) actually wrote a detailed tutorial showing how he used multiple tools to avoid polar distortion, when he helped do cartography for Bruce Heard's World of Calidar project:
http://thorf13.blogspot.co.uk/2013/12/thorfs-world-building-techniques_11.html

I've read through this multiple times, and get the general idea, but it is a very complex issue. I've spoken to Thorf about it on The Piazza:
http://www.thepiazza.org.uk/bb/viewtopic.php?f=85&t=11489

I think it would need to be another stretch goal, but if you could get Other World Mapper to do all the annoying spherical mathematical geometry stuff, you could maybe give OWM users some sort of "polar shift" ability, where they can work on the north and south poles, without needing to make them into long strips outside of your software. Then they could design the continents close to poles that look the shape they want them to look from above.

What do you think?
@David Are you asking for the option to have Other World Mapper take a landmass and turn it into a polar landmass (long strip)? So you could work with the "shape" you want, but then have a correct Equirectangular representation in the map? I want to make sure I understand fully before answering!
I think I might have been a bit confusing there, luckily the OWM team are uber patient and willing to talk about things. :)
Other World Mapper at Kickstarter wrote:
David Shepheard at Kickstarter wrote:Yes. Something like that. I'm not entirely sure what the best way to do it would be, because I'm not a great cartographer (not yet anyway).

All I know is that people that are not experts often seem to not even realise that making poles for maps is difficult. And even when people do realise it is difficult, they don't seem to know how to get around the problem, unless they go use a bunch of other tools, like Thorf did. And most people can't do what Thorf does, because he has spent years studying how to make poles work.

Maybe if the data was stored normally (is that the equirectangular representation) but we were able to "move a camera" up over the top of the pole, we would be able to draw an island that looks approximately circular, but have the data stored corrrectly (to make that long strip).

From what I could tell of Thorf's technique, he went backwards and forwards, distorting data using G.Projector and then fixing errors that G.Projector dropped into his data. I think that changing the viewpoint, but not saving the data the "original way" (instead of saving it in a new projection and then bending it back to the original view) could avoid the need to fix things.

I'm not sure of the exact maths here. I realise that spheres are a bit tricky. I think this would be a fairly hard bit of programming. But I think that if you had a stretch goal to solve this problem, it could help a lot of people solve a problem that most people don't understand.
@David We have planned something like that, which would allow you to work on the poles separately, and take care of turning them into the proper Equirectangular projection, if you create your map project as an spherical world map . However, it's going to have to be a later stretch goal (or something for after the first release).

Thanks!
So I'm happy that OWM is going to deal with this weirdness, but I'm not sure if it is going to do it on Version 1.0 or somewhere a bit later down the line.

I think that generally, with things like computer games, they "cheat" and just ignore the fact that planets have poles. If you have a game like World of Warcraft, and you don't allow your players to have full access to the planet, you can pretend that a rectangular map is a spherical map, but design a map that is a cylinder...and your players are never going to know. But I think the OWM team are going to up their game and go beyond what the competition can do here. 8-)

I think it is great that you want to design a polar setting, Gareth. Because if there is going to be any sort of distortion when OWM first try to solve the polar problem, I think that someone like you could be the person who designs the map that shows that up. If it works for you, it is probably going to work for everyone. :D
gareth_w wrote:The only thing I can think of that might help in software is some sort of variable grid lines, so as you move toward or away from the equator the grid lines move to compensate.
As you get towards the pole, I am pretty sure that grid lines would all converge into a single point. What is meaningful near the equator is pretty meaningless within a few miles of the pole. Or maybe not meaningless, but something that needs to be interpreted in a different way.

Perhaps your setting would have grid lines that radiate out from a central point and other grid lines that are a series of circles that are equal distances from your pole. You are probably going to have a pole that is uninhabitable and deadly cold, so perhaps you might have the central area cause "cold damage" and have less and less cold damage as people cross the various circles around the pole (until you get to the stage where it is possible for people to live). There might also be a circle where things like trees can start to live.

I'm not sure how large an "Arctic Circle" should be, but on a planet with tilt, you would have a zone that has 24 hour daytime or 24 hour nighttime. And you might also have "Northern Lights" be more probable inside a specific circle. So circles on your map (instead of horizontal and vertical grid lines) could actually help with world-building).
David "Big Mac" Shepheard
(A Spelljammer fan hoping to user Other World Mapper to make lots of maps of planets.)
You can see more of me over at The Piazza campaign settings forums

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Re: How many people here are good at making polar maps?

Post by gareth_w » Fri Nov 21, 2014 2:30 pm

The moving gridlines (medians, parallels, latitiudes, longitdues) - and by this I mean curving on the display - would be the best tool.

I think it is always best to work flat, but as you rotate the globe you get a different flat bit to work on . You then get to see the perspective of the other bits to compare. That would be the ideal for me. Without this, the difficult thing is gauging how distance A-B near the pole compares to distance X-Y at the tropics.

I'm currently working with a bit of a cop-out solution where I'm only showing a partial globe in my map! Plus the fact that it's an essentially medieval setting, and they don't have GPS and can't measure the distances to the mm. Plus I'm the GM and if I say it's a 3 day walk, it's a 3 day walk unless you want to slow it down with more "random" encounters!

My Main Map:
http://www.odyle.co.uk/Erlambir/content/nations-map

My Northern Map:
http://www.odyle.co.uk/Erlambir/content/nordhelm-map

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Re: How many people here are good at making polar maps?

Post by Kanchou » Sat Nov 22, 2014 1:39 pm

gareth_w wrote:The moving gridlines (medians, parallels, latitiudes, longitdues) - and by this I mean curving on the display - would be the best tool.
The stretch goal that added additional map projections added elliptical projections (AKA Mollweide projection) that would take care of at least part of what you are discussing. Of course, the map itself would be made on that projection.

http://en.wikipedia.org/wiki/List_of_ma ... ion_SW.jpg

A possible future feature we've thought about, would be to generate a view in a different projection from your map (i.e. generate equirectagular map from elliptical projection map, and vice verse).
Big Mac wrote:So I'm happy that OWM is going to deal with this weirdness, but I'm not sure if it is going to do it on Version 1.0 or somewhere a bit later down the line.

The multiple map views in the same map project opened the door to having the feature to work on the poles separately, but it is likely a post release feature. In essence, the pole view would look like the pole part of the Gauss conformal projection
http://en.wikipedia.org/wiki/List_of_ma ... ranEll.png

- Alejandro
Alejandro S. Canosa
Three Minds Software

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Re: How many people here are good at making polar maps?

Post by Laoena » Sun Nov 30, 2014 5:59 am

Interesting. Are you planning on having the main map in a latitude / longitude co-ordinate system then? Or planning on draping a 2d map over a 3d spherical surface? You will get some distortion that way.

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Re: How many people here are good at making polar maps?

Post by Kanchou » Sun Nov 30, 2014 1:41 pm

Laoena wrote:Interesting. Are you planning on having the main map in a latitude / longitude co-ordinate system then? Or planning on draping a 2d map over a 3d spherical surface? You will get some distortion that way.
The feature that is part of the first release from the Kickstarter is to have parallel and meridian overlays in the map to match different projections, so you are building the map in that projection already.

For the future features we talked about, the main map would be in a latitude/longitude coordinate system, and the other projections calculated from the main map (to go between projections, or to work on the poles on the side and them being converted back to a equirectangular projection).

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Re: How many people here are good at making polar maps?

Post by Big Mac » Thu Dec 04, 2014 5:30 pm

Kanchou wrote:
gareth_w wrote:The moving gridlines (medians, parallels, latitiudes, longitdues) - and by this I mean curving on the display - would be the best tool.
The stretch goal that added additional map projections added elliptical projections (AKA Mollweide projection) that would take care of at least part of what you are discussing. Of course, the map itself would be made on that projection.

http://en.wikipedia.org/wiki/List_of_ma ... ion_SW.jpg

A possible future feature we've thought about, would be to generate a view in a different projection from your map (i.e. generate equirectagular map from elliptical projection map, and vice verse).
That sounds like it would do exactly what NASA's G.Projector software does, but inside OWM.

I don't think I would personally want to use all the different types of cartographic projection myself. I do not even understand the advantages of all of them - I've only worked out the "selling points" of a fairly small subset of them - but I think that would really open up OWM to fans of those individual projections. (If the Kickstarter was still going, or if you were doing OWM Kickstarter 2, I would probably suggest doing a poll to find out the most popular map projections and then make support for each one its own stretch goal.)
Kanchou wrote:
Big Mac wrote:So I'm happy that OWM is going to deal with this weirdness, but I'm not sure if it is going to do it on Version 1.0 or somewhere a bit later down the line.

The multiple map views in the same map project opened the door to having the feature to work on the poles separately, but it is likely a post release feature. In essence, the pole view would look like the pole part of the Gauss conformal projection
http://en.wikipedia.org/wiki/List_of_ma ... ranEll.png
I do know that this problem is a very complex one. And I know that there are only a certain number of cartographers (like Thorfin Tait) who can instinctively work out how to do this sort of thing in their head. So I would be very surprised (happily so) if you could add this on Version 1.0.

I think that getting the main features to work is going to have to be your main priority. This is going to be the cherry on the cake, if/when you can work out how to make this easy enough for people like me.
Kanchou wrote:For the future features we talked about, the main map would be in a latitude/longitude coordinate system, and the other projections calculated from the main map (to go between projections, or to work on the poles on the side and them being converted back to a equirectangular projection).
Yay! That is exactly how I wanted it. Thanks Alejandro! :D
David "Big Mac" Shepheard
(A Spelljammer fan hoping to user Other World Mapper to make lots of maps of planets.)
You can see more of me over at The Piazza campaign settings forums

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