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Thread: Program to calculate size of map and point to point distance.

  1. #21

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    I have absolutely no idea if I can help in your specific case (because my husband is speaking loudly with a student at the moment and I'm unable to focus enough and read the full thread ^^'), but Photoshop itself has a tool for measures of distances & areas. Have a look there maybe :
    - In Italian,
    - In English,
    - In French.

  2. #22
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    Quote Originally Posted by waldronate View Post
    You can keep using the demo after the month trial, you just can't export or save data. You can keep measuring distances and viewing things as long as you like. Nothing ever prevents you from taking a screenshot of the program to collect data.

    To import your data, you need to do a little math. Your scale bar says that it's 120km across. Loading the map in Photoshop, selecting the scale, copying it, and making a new map from the copy shows that your scale bar is 197 pixels across (for simplicity of the math, I'll declare it to be 200 pixels wide). That means that each pixel in your map is just about 0.6km across (120km/200pix=0.6km/pix). Your whole map is 2000pix by1500 pix, meaning that the map is 1200km by 900km.

    For a spherical Earth-sized world (40000 km around at the equator and from one pole through the other and back again), that means that your map is 1200/40000*360=10.8 degrees across and 900/40000*360=8.1 degrees high. Why do you care about that? Because FT's image import assumes that the map edges are specified in degrees. Because we've declared that the map is "flat enough", we don't have to worry about the consideration that FT wants Equirectangular projection images as its input. Because we're only concerned about measuring distances, we can center the image at the equator to reduce errors. If you want to put that image at a specific point in the world, you'll need to reproject that base image using a program such as ReprojectImage ( http://fracterra.com/ReprojectImage.zip ).

    Due to a quirk in FT's image process, you need to flip the top and bottom edges to get things upright.

    The image below shows how you'd attach your map to an FT world on the left and a measurement across the central lake using FT's ruler tool.

    You have a map that already has a scale on it. As described above, your scale can be used to make the map the correct size for a world. If you export from FT to CC3, the scale should be correct for that map. The FT demo is very resolution-limited, so outputting to CC3 from the demo isn't a whole lot of use. You already have a map in Photoshop with the scale on it (that's how you made the JPEG, right)? When the map is imported into F, the original calculations above were done to ensure that FT's understanding of your map was a close match to the information originally expressed in your scale bar.

    Attachment 116019
    I didn't realize how small my test map was before seeing it on the Fractal Terrain globe .

    Wanderful, so FT is everything i need .
    Thanks verry verry thenks I will try to buy it in the future.

    One last question , from how i have undstand more small are the map more precise are the measuration, right?
    That becouse in the future i wanna make one map more large then this (the map for my book, becouse this map is only a test map, for testyng my abilitys and learn how to make a map), maybe the size of south america more or less, do you advice me to create that map in FT and export in photoshop? Bypassing CC3? Can i?

    If i export my map in Photoshop from FT, i dont loose the scale? Maybe if i wanna reupload the map in FT to measure?
    That becouse my plan is to create my own world in FT and use only one continent for my book and preserve me the rest of the world to the future.

    For that reason im searching a method to measure the map, is verry important to me .


    Thenks again for all .

  3. #23
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    Quote Originally Posted by MistyBeee View Post
    I have absolutely no idea if I can help in your specific case (because my husband is speaking loudly with a student at the moment and I'm unable to focus enough and read the full thread ^^'), but Photoshop itself has a tool for measures of distances & areas. Have a look there maybe :
    - In Italian,
    - In English,
    - In French.
    interesting
    Thenks i did not know. I will try.

    Edit: i have the standard edition i cant use that function
    Last edited by Elros; 06-13-2019 at 06:57 AM.

  4. #24
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    One of the problems of a map on a globe is that traditional fantasy map decorations like a scale bar and compass rose start to lose meaning as a map covers a larger and larger area of the globe. This change in meaning has to do with the map projection (the transformation from a sphere to a flat map). The scale bar and compass rose are useful for maps that over a small area because the direction is well-defined and the scale doesn't change enough to matter. https://www.reddit.com/r/MapPorn/com...ing_continent/ shows a worst-case example of what can happen to a compass rose (a compass rose on this map wouldn't be useful because there isn't a single direction "north"). Cylindrical map projections such as the well-known Mercator and Equirectangular projections are examples where a scale bar isn't very useful because the scale on such a map is true only at one latitude and is progressively more wrong as you approach the poles.

    I don't know that CC3 would be useful for your problem unless you want to use it to create or decorate maps. If you're already comfortable using Photoshop for mapmaking, CC3 might not add much. FT3 can be useful for keeping multiple maps consistent in projection. For example, a rough outline of the world in FT can be used to get template images in a desired projection and then those template images can be fleshed out in Photoshop to get your final maps.

    You can then (if desired), push those final maps back into FT and measure on their surface. If you use a projection other than Equirectangular for your Photoshop map, you will need to reproject the image back to Equirectangular before importing it into FT, but that's not too difficult to do.

    In any case, FT will be able to give you accurate physical distances as long as your inputs are well-defined. It's like a low-end GIS system in some ways.

    One thing to consider is that a physical distance across the map likely doesn't have a direct mapping to time of travel. A horse travels very different distances along roads on a grassland as opposed to forging across high mountains or swamp. FT doesn't have a "time of travel" calculator, just a distance measurement tool.

  5. #25
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    Quote Originally Posted by waldronate View Post
    One of the problems of a map on a globe is that traditional fantasy map decorations like a scale bar and compass rose start to lose meaning as a map covers a larger and larger area of the globe. This change in meaning has to do with the map projection (the transformation from a sphere to a flat map). The scale bar and compass rose are useful for maps that over a small area because the direction is well-defined and the scale doesn't change enough to matter. https://www.reddit.com/r/MapPorn/com...ing_continent/ shows a worst-case example of what can happen to a compass rose (a compass rose on this map wouldn't be useful because there isn't a single direction "north"). Cylindrical map projections such as the well-known Mercator and Equirectangular projections are examples where a scale bar isn't very useful because the scale on such a map is true only at one latitude and is progressively more wrong as you approach the poles.

    I don't know that CC3 would be useful for your problem unless you want to use it to create or decorate maps. If you're already comfortable using Photoshop for mapmaking, CC3 might not add much. FT3 can be useful for keeping multiple maps consistent in projection. For example, a rough outline of the world in FT can be used to get template images in a desired projection and then those template images can be fleshed out in Photoshop to get your final maps.

    You can then (if desired), push those final maps back into FT and measure on their surface. If you use a projection other than Equirectangular for your Photoshop map, you will need to reproject the image back to Equirectangular before importing it into FT, but that's not too difficult to do.

    In any case, FT will be able to give you accurate physical distances as long as your inputs are well-defined. It's like a low-end GIS system in some ways.

    One thing to consider is that a physical distance across the map likely doesn't have a direct mapping to time of travel. A horse travels very different distances along roads on a grassland as opposed to forging across high mountains or swamp. FT doesn't have a "time of travel" calculator, just a distance measurement tool.
    I could use city names instead of geographic coordinates to solve the problem of the many north direction.
    How much inaccurate are the scale bar in a map like south america?

    I dont need precision, i suppose approximately 10 miles is 1 day of walk, maybe more maybe less.
    The important thing is: if the reader wants to establish the distance between two places, he can do it without destroying the credibility of my story.
    In north america 100 km in straight line to the north direction, in an equirectangular map, how much are in the real world? I can afford a bit of error space, since the story takes place in the Middle Ages.


    Last question: if i import a map from FT to photoshop, how can i find out the scale of map? Is indicated somewhere?

    In any case, thanks for all the patience you're having with me. I'm really grateful.

  6. #26
    Administrator waldronate's Avatar
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    http://desktop.arcgis.com/en/arcmap/...F-FC70BE1F7E8D offers suggestions for picking a suitable map projection. How accurate a scale bar would be on something like South America depends entirely on the chosen projection.
    FT3 can export a scale bar in the CC3 version of the map. That scale bar is valid only for the precise center of the map, however.
    FT3 doesn't offer an on-screen scale bar, but it does have an information window that will show the visible extents of the screen area measured across the middle and center of the display.

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    Quote Originally Posted by waldronate View Post
    http://desktop.arcgis.com/en/arcmap/...F-FC70BE1F7E8D offers suggestions for picking a suitable map projection. How accurate a scale bar would be on something like South America depends entirely on the chosen projection.
    FT3 can export a scale bar in the CC3 version of the map. That scale bar is valid only for the precise center of the map, however.
    FT3 doesn't offer an on-screen scale bar, but it does have an information window that will show the visible extents of the screen area measured across the middle and center of the display.
    What is the most commonly used projection in the fantasy maps on books? Equirectangular as i have undstand, right?
    Using that projection, how much are the the imprecision?


    How can i set the scale in photoshop when i have imported the map from FT ? I mean, how can i visually set the layer?

    Maybe is not much important the scale but i want give at the readers an idea of map size.

  8. #28
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    Most fantasy maps that I have seen don't specify a projection because it usually isn't important to the story. Equirectangular is a horrible projection because its distortion is 1/cos(latitude), meaning that it's literally infinite distortion at the poles. If you're not drawing a latitude/longitude graticule on your map, you can assume that it's in a projection that's flat enough for storytelling purposes.

    The simplest way to give users a sense of scale is to use a scale bar on the map, even if it's not precisely correct. The simplest way to ensure scale transfers from FT to something line Photoshop is to draw a rectangular island or two of known size off of one or more coasts. Then mask out those islands in your final map using a legend or title layer.

  9. #29
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    Most fantasy maps use no projection at all, not out of any particular thought but rather it's just easier that way. ie, their maps occur 1x1 as if the world was flat. and then they sort of stick it like a post it on their globe if they later expand their setting. The only fantasy world I can think of that this would actually work for is Discworld, but I don't think it's something one needs to worry about really.

  10. #30
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    Quote Originally Posted by Falconius View Post
    Most fantasy maps use no projection at all, not out of any particular thought but rather it's just easier that way. ie, their maps occur 1x1 as if the world was flat. and then they sort of stick it like a post it on their globe if they later expand their setting. The only fantasy world I can think of that this would actually work for is Discworld, but I don't think it's something one needs to worry about really.
    So i can create my own world, then isolate one continent and i dont have to worry about projection?

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