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Iggy
09-02-2013, 02:26 PM
I've been struggling how to produce a globe world map in Photoshop CS6 that uses a world projection type. I've read a thing or two around here, particularly this thread on map projections (http://www.cartographersguild.com/general-discussion/23098-map-projections.html), brought to my attention in the topic where I posted my world map (http://www.cartographersguild.com/regional-world-mapping/24507-my-first-world-map-feedback-wanted.html) which doesn't use a world projection, but it still evades me how I can paint landmass on top of the provided templates that follow the curves of the world projection as pointed out in this post (http://www.cartographersguild.com/general-discussion/23098-map-projections.html#post213549). Other programs like Flex Projector (http://www.flexprojector.com/index.html) came to my attention through here (http://www.cartographersguild.com/regional-world-mapping/23609-map-projections-using-flexify.html) as well as Quantum GIS (http://www.qgis.org/) and G.Projector (http://www.giss.nasa.gov/tools/gprojector/) but do I need to use these or is Photoshop all it takes? Sure, with Flexify 2 I can easily transform a flat land map (http://i.imgur.com/92yzrPr.jpg) into a globe in Winkel Tripel (http://i.imgur.com/KYX5bnx.jpg) but I don't see how that brings me any closer in making a proper globe map.

Photoshop tutorials I have seen so far do not cover the subject of world projection so those are not helpful.

I need a proper map for a fantasy novel I'm working on, I could resort to a complete flat land but I would rather have a (proper) globe world. I need to get the geography right before I continue.

Azelor
09-02-2013, 02:42 PM
Do you mean an orthographic projection? Orthographic projection (cartography) - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Orthographic_projection_%28cartography%29)

It would make your world look like a globe seen from space just like earth.

Iggy
09-02-2013, 02:45 PM
Yes. I was pointed out to at least use a world map projection type, the exact how to do this still evades me after doing some searching around on it hence this topic.

I feel as I've seen all pieces of the puzzle but how to put it together is still not clear to me.

Azelor
09-02-2013, 02:46 PM
Do you plan to keep your already made landmasses ?

Iggy
09-02-2013, 02:51 PM
It is no problem if I have to make it all over again.

Azelor
09-02-2013, 02:56 PM
Ok well then if you paint your map using a layout what is the problem ?

Personaly, I made a world map before thinking about the projection. It seems to be equirectangular, but even so, I'm not sure. If I want to, I can say that it's Hammer or mercator as long as the world fit the layout and the climates remains similar.

Hai-Etlik
09-02-2013, 03:51 PM
I can easily transform a flat land map (http://i.imgur.com/92yzrPr.jpg) into a globe in Winkel Tripel (http://i.imgur.com/KYX5bnx.jpg) but I don't see how that brings me any closer in making a proper globe map.

I think you've got this a bit backwards. The "real" shape is a globe, as in a 3D, close to spherical shape. Any map is a distortion of the globe because it's flat, while the globe is not. The particular way that flattening is done is the projection.

You can think of it as if you put a light at the centre of a clear sphere with the features painted on the surface. Then held a flat piece of paper up to the globe, and traced out the shadows cast on it. This particular projection is called Gnomonic and it's used in geology, and for building projections on the surfaces of polyhedra. Other projections role the paper into cones or tubes, move the light, or even bend the light or do other strange things.

So don't think about drawing a flat map and then putting it in a projection. Think about drawing in a projection, and then changing to another projection. You need to draw the distortion for the first projection into the map otherwise when you change projections, you'll get the reverse of that distortion combined with the distortion of the second projection. Even if you stick with the original projection, you still need to get that distortion right or the map will look wonky to anyone familiar with real maps.

One thing to ask yourself is, just how much area does the map need to cover? Do you really need a map of the whole globe? Smaller extents are easier. You still need to think about where you are on the globe and pay some attention to projections, but it's a lot easier. You should also think about what kind of map it is and what level of cartographic and surveying sophistication was employed. It might be that dropping things you are used to seeing on modern maps like graticules, compas roses, scale bars, or even trying represent the spatial relationships between things at all will make your life easier. In the times most fantasy draws on, maps were fairly rare, and tended to be more topologocal than topographic; they were about connectedness rather than shape and distance, more like a modern subway map. They also had very poor source material to work with.

Iggy
09-02-2013, 04:58 PM
So don't think about drawing a flat map and then putting it in a projection. Think about drawing in a projection, and then changing to another projection. You need to draw the distortion for the first projection into the map otherwise when you change projections, you'll get the reverse of that distortion combined with the distortion of the second projection. Even if you stick with the original projection, you still need to get that distortion right or the map will look wonky to anyone familiar with real maps.

Can I do this with just Photoshop CS6 or do I need some of the other applications I named in my openings post?



One thing to ask yourself is, just how much area does the map need to cover? Do you really need a map of the whole globe? Smaller extents are easier. You still need to think about where you are on the globe and pay some attention to projections, but it's a lot easier. You should also think about what kind of map it is and what level of cartographic and surveying sophistication was employed. It might be that dropping things you are used to seeing on modern maps like graticules, compas roses, scale bars, or even trying represent the spatial relationships between things at all will make your life easier. In the times most fantasy draws on, maps were fairly rare, and tended to be more topologocal than topographic; they were about connectedness rather than shape and distance, more like a modern subway map. They also had very poor source material to work with.

I would greatly prefer it to have a good world map of my realm. It needs to show locations of capitals, borderlines of kingdoms and I should be able to calculate the distance between two points so I can determine how long my character's travel should take. I will make maps of smaller regions based on it later. I know that some fantasy authors such as J.R.R. Tolkien and David Eddings started their projects with a map (heck, Edding's entire fantasy career started with a map!) and both advise to get your geography right.


Ok well then if you paint your map using a layout what is the problem ?

Personaly, I made a world map before thinking about the projection. It seems to be equirectangular, but even so, I'm not sure. If I want to, I can say that it's Hammer or mercator as long as the world fit the layout and the climates remains similar.

I simply don't know how. If drawing land mass on top of a template such as this (http://www.cartographersguild.com/attachments/general-discussion/53786d1366487180-map-projections-mollweide2a.png) is a good way to start, how does one do this in Photoshop? Alternatively, if I have a flat land, how do I add the right distortion for the projection type I want?

waldronate
09-02-2013, 05:31 PM
The ultimate cheat to avoid confusion about projections is to go to your local thrift store and buy a used globe. They're usually pretty cheap, at least around here. Then spray paint it flat white and draw on its surface to rough things out. From there, you can stitch together and reproject a few pictures to get an image in something like the Equirectangular projection.

If you're intent on doing a digital-only map, try using a template like the one you referenced above. Load it into Photoshop and resize as appropriate. Then make a new layer and draw onto that. Once in a while, use a program that supports reprojecting images like G.Projector to see how your map looks in other projections. Drawing in the distortions digitally can be a bit confusing because of how the grid lines converge toward the poles.

Ideally, you'd use a paint program that has an understanding of projections, but I haven't run across a good and easy-to-use one yet. If I'd ever get things in gear and add projective brushes to Fractal Terrains, it would be close to suitable for this use. As it is, FT does make viewing things in various projections a little easier, if not exactly correct.

As far as reprojecting your flat map into a world map, it's a matter of what you already have. If your continents are reasonably equatorial, you can probably just select an existing projection like Mollweide or Hammer and declare that your map is defined in that projection (any distortions around the edge are likely to be far away from the primary area of interest along the central meridian and you can simply say that they are due to cartographic error).

Iggy
09-03-2013, 01:37 PM
Thanks for the suggestions, I'll try out some tricks. I also found this PS plug-in called Spherical Mapping Corrector (http://www.richardrosenman.com/software/downloads/) that might help with creating the right distortion.

Thorf
09-04-2013, 11:02 AM
Iggy, I think perhaps what you need is a little knowledge of projections and distortion. What are the dimensions of your current map? In many ways the easiest projection to work in is the equirectangular, which is just a regular grid of squares with latitude and longitude plotted on them like a graph. This projection uses a 2:1 image, for example 6000 x 3000 pixels, and it's perfect for using as an overlay in Google Earth so you can see how things "really" look on your spherical world.

The next step is to read up about and play with the distortion. Basically, there is no perfect projection of a sphere - all projections distort something, and in fact most projections only preserve one or at most two aspects of the following: shape, area, distance and direction. Some preserve none of these aspects, instead choosing to compromise.

What you need to know about equirectangular maps is that they preserve distance along the equator and along all meridians (north-south), but east-west distances away from the equator are progressively more and more stretched, until the poles are represented by lines the entire width of the map. You can clearly see how this works if you overlay your map on Google Earth.

The approach I have taken with this in my world maps is to start off with an equirectangular map, then reproject it using G.Projector to do both poles, as well as any other region I want an exact shape with. Specifically, if you reproject into equirectangular oblique centred on your area of interest, then do your design, and finally reproject back to equirectangular and update your original map, you should end up with a good base map. G.Projector is a bit fiddle in this regard, but it does work.

The final step of course is to choose whatever projection you like best to present your world map in. It's important to remember that no one projection will do everything you want it to. Also, you should realise that large scales (local) are inherently less distorted than small scales (regional and world). If you want to do measurements, it may well be better to make several large scale maps of important areas.

Iggy
09-06-2013, 03:55 PM
This is the current map (http://i.imgur.com/jDoN9kb.jpg) I'm working on, it's 6000x3000 pixels, up scaled from 2000x1000 pixels before, no projection so far. I think my problem is that I understand the process you describe, not how you carry it out.

I couldn't find the Photoshop plug in that I mentioned in my previous post so that one is out.

Azelor
09-06-2013, 04:54 PM
Just to be clear, your map as it is right now uses a projection. No projection would mean that your map have the shape of a globe and is rendered in 3D. Projections exist so we can show Earth on a flat piece of paper wich is more useful but lee accurate than a globe. So doing a rectangular map mean you used a projection, even if you were not aware of it.

If you want no projection, my guess would be that you use a 3D software to create a sphere and then paint on that sphere. Maybe PS6 can handle it, I have no idea.

Maybe I just repeated what the others said but I am not sure to understand what is not working.

waldronate
09-06-2013, 05:13 PM
If you can identify some points on the map and corresponding latitudes, folks here should be able to recommend a projection and/or process that might be helpful. Polar regions, for example, are best painted in a polar projection. Equatorial regions are generally good using a cylindrical projection. Regional maps might benefit from an azimuthal projection with its center of projection in the center of the map. Local maps are usually small enough that the distortion is minimal as long as the center of projection is in the center of the map.

As always, it's a matter of what you're optimizing for (which differs with the type of map).

I really, really need to spend a couple of weeks working on FT's brush tools to get useful dynamics and projective brushes. If only I had time and money...

Iggy
09-08-2013, 12:02 PM
I found out something that might be helpful. Photoshop CS6 Extended has 3D functionality through which I can create a sphere and paint directly on top of that. Here's how it looks (http://i.imgur.com/SWNLEir.jpg). I haven't figured out how to sharpen the blurry lines of the grid and the sphere itself but what I have seen so far looks promising. I'm also curious if I can export the texture of the sphere as a flat image using a map projection type. To be continued.....

vorropohaiah
09-08-2013, 12:19 PM
you really need to work with an equirectangular base map if youre going to be projecting it ontoa sphere, otherwise your poles are going to start looking kinda odd (to say the elast) once you wrap the skin around a globe

Iggy
09-08-2013, 04:16 PM
you really need to work with an equirectangular base map if youre going to be projecting it ontoa sphere, otherwise your poles are going to start looking kinda odd (to say the elast) once you wrap the skin around a globe

How does one start with an equirectangular base map? (In Photoshop to be precise) Can I use my existing map or do I need to start from scratch? I loaded my map in G.Projector, applying the equirectangular projection had no effect. I think equirectangular projection is sufficient for my map.

I've searched quite a bit on Google on this whole subject and I just can't find much that helps me further. Lots of tutorials on stuff but not what I was looking for.

Azelor
09-08-2013, 07:50 PM
If you can, you should export the spherical map into an equirectangular projection. But now that you have a globe, why would you want a flat map? :)

You start an equirectangular projection by making the latitudes and longitudes lines always at the same distances. So you end up with a grid made of equal sized squares. Your map is already rectangular so do as Thorf said: keep a ratio of 2:1 ( the lenght is twice the height). That's prety much all there is to do.

Iggy
09-09-2013, 05:31 AM
If you can, you should export the spherical map into an equirectangular projection. But now that you have a globe, why would you want a flat map? :)
Exactly my thought. I will continue to play with it and do some searching. if there's anything worth mentioning I'll post it.

Hai-Etlik
09-14-2013, 08:36 PM
How does one start with an equirectangular base map? (In Photoshop to be precise) Can I use my existing map or do I need to start from scratch? I loaded my map in G.Projector, applying the equirectangular projection had no effect. I think equirectangular projection is sufficient for my map.

I've searched quite a bit on Google on this whole subject and I just can't find much that helps me further. Lots of tutorials on stuff but not what I was looking for.

It has no effect because G.Projector assumes that you are starting with that projection. The option is there so you can shift the standard parallels or to apply overlays. Of course if the map isn't in a normal aspect equirectangular/equidistant cylindrical projection to begin with, putting it though G.Projector isn't going to do anything to fix it.