Very Large Maps, is it a problem?

[Redrobes]

Bigger maps does not necessarily mean a slow down its just generally true due to the way they have programmed the app. I have done raster maps up to 40K using about 30 layers but you cant generally do it with the usual apps and methods. The main thing I would suggest is to tile your map and deal with one tile at a time - much like doing one continent as Kodiak says.

I would suggest first looking at what res you need. I expect that you need a certain resolution at some points of the map and higher in specific other areas and probably much much higher in cities etc - a resolution which is completely unreasonable to map the whole world at. I.e. Although you may need quite a high res for the world map its probably not 40K sqr. I don't think there are any standard pixels per mile type resolutions and in any case some apps will cope with a variety of resolutions and scales.

[waldronate]

There's also a matter of personal expectations. Some folks are perfectly fine with operations taking 20 seconds, others find operations that take longer than 2 seconds to be intolerable. I recommend working at a medium resolution (4kx2k or so) to get the world and then do more local areas as has been suggested. This technique will balance the amount of data the machine has to handle against the quality of the final output. And, the bigger the machine, the larger the map before you hit the slowdown where it has to swap to disk continually.

The biggest problem with this technique is that certain whole-image operations are extremely sensitive to the size of a pixel in order to get plausible results. The most common example is fluvial erosion. In the case of erosion, a river is almost never even a pixel wide, but most flow analysis and erosion algorithms require and/or generate rivers more than one pixel wide. The results are beautiful, but they have a certain signature to them, just as most simple fractally-generated terrains do.

[Yandor]

hmm weird my second post didn't make it, I understand the whole dpi when printing and all that, I was just wondering what people personal preference on the dpi when using such a large image size. Cause I wouldn't assume you would have a 300 dpi on a 10,000x10,000 image, but on the reverse side if you are using that big of an image do you lower the dpi down a lot (say in the 40's 50's instead of the standard 72)? Thats really what I was getting at

[Gamerprinter]

It depends on your final needs - how will the map be used. If intended for print, like most my maps, I say a minimum of 200 dpi for print. If your intended use is for a Virtual Terrain app, 30 or 50 ppi is plausable, though I know many VT users who prefer 100 ppi, so you can zoom in and still see detail. If your map will only appear as a way graphic for say PbP, 72 or 96 ppi is optimum as it is only intended to fit on a computer monitor and that's likely to be 1024 x 768 or some other screen size factor.

Whatever your use for a map is the pixel dimension it should be designed for. It varies.

GP

[a2area]

hmm weird my second post didn't make it, I understand the whole dpi when printing and all that, I was just wondering what people personal preference on the dpi when using such a large image size. Cause I wouldn't assume you would have a 300 dpi on a 10,000 x 10,000 image, but on the reverse side if you are using that big of an image do you lower the dpi down a lot (say in the 40's 50's instead of the standard 72)? Thats really what I was getting at

As i get into larger and larger maps i have to tile them, especially in wilbur, probably because i'm running vista (ugh) on a mac. It really doesn't matter what the ppi is until you output it so i generally work at 72 ppi for monitor/web resolution. ppi doesn't make any difference in document size as long as the pixel dimensions stay the same... the only real working difference is that when you zoom to 100%, the larger the ppi the smaller it will appear on the screen.

[PhrozenDragon]

Thanks for the replies, way more than I expected.

Something else i have picked up is having two files... one labeled filename_backup which i'll save out to occasionally. With work that big saving can take a while and you never know when something might glitch and freeze up.. at least you'll have an extra file rather than one corrupt file!

I never thought of it, but I'll remember to do that.

As for keeping multiple files, I don't know that I have the patience to carry that out just yet. I suppose I'll have to resort to it though if things to start to slow down though. Though I could of course cut away a lot of ocean to conserve space. No need to go around the entire globe if there's nothing but water at the edges.

Another thing you may want to do is build all of you continents seperately, so you are only generally working with maps 1/4 to 1/8 of your desired world size. When you have finished all of your continents, make your 40000x20000 blank canvas, and add your continents to it. This way you only have to deal with slow down for the final stages of your map as opposed to getting decreased performance the longer you work on it.

I thought of that, but the world is mostly one super-continent, so I figured it would be hard to make sure mountain ranges, rivers and forests lined up in the final version if I did it this way.

But to answer your question, it really depends on what software you are using. Sounds like Photoshop or GIMP, both with lots of layers and pixel area are problematically slow. That's why I use a vector app with robust image handling capability, Xara Xtreme, and that I create most of my maps with the intention of printing - as I run Gamer Printshop and specialize in printing large format maps. If you're using an image editor and using lots of layers, performance will go down, its how the application manages memory.

I have 4GB of RAM, running Vista. Also, does it matter that it's going to be just black&white?

I guess I'll just have to test and find out. And yes, I'm using Photoshop.

I would suggest first looking at what res you need. I expect that you need a certain resolution at some points of the map and higher in specific other areas and probably much much higher in cities etc - a resolution which is completely unreasonable to map the whole world at. I.e. Although you may need quite a high res for the world map its probably not 40K sqr. I don't think there are any standard pixels per mile type resolutions and in any case some apps will cope with a variety of resolutions and scales.

Well of course I can't add citiy maps to it, I didn't mean that great amount of detail

I do hope it will be helpful for me to be able to get a sense of how big (and far away) things are from each other if I can mark down more than just a country and capital, but also towns and smaller lakes and forests (which I found hard to represent in my smaller map).

[Midgardsormr]

4GB on Vista might be straining for an image that size. If you were in XP, you'd have an easier time of it. Windows 2000 would be better still. Seems backward, doesn't it? If you start to have problems, try turning off Aero and any other unnecessary bells and whistles. Vista seems to have pretty good memory management in my experience, but it's still rather bloated.

Reducing the color depth, though, will help you a lot. Are you really talking black-and-white (1 bit) or grayscale (8-bit)? A 1-bit image is going to be light enough that you'll probably be fine even at the huge size you're talking about. An 8-bit grayscale is still better than full color, as it has only 1/2 the amount of information that an RGB image has (assuming that you're working non-destructively. 1/3 if you're not using masks.) Just make sure you're actually in greyscale mode, though, or you won't get any of the benefits. Image > Mode > Grayscale.

[PhrozenDragon]

Reducing the color depth, though, will help you a lot. Are you really talking black-and-white (1 bit) or grayscale (8-bit)? A 1-bit image is going to be light enough that you'll probably be fine even at the huge size you're talking about. An 8-bit grayscale is still better than full color, as it has only 1/2 the amount of information that an RGB image has (assuming that you're working non-destructively. 1/3 if you're not using masks.) Just make sure you're actually in greyscale mode, though, or you won't get any of the benefits. Image > Mode > Grayscale.

Yes, I meant 8-bit. Sounds worth a shot then.

[The Stoat]

I am designing a campaign world that I intend to be very large. The two things I am finding I need to do is tiling and different scales. The large scale maps give overviews and keep the tiles in alignment. I am using Gimp for my mapping. I am learning as I go how to transfer the different elements between maps so I can change the scale of elements such as roads, mountains and rivers.
I imagine it as taking a page from the google earth playbook letting me scale up to continents and down to a village and both will hold consistency.

[Natai]

Here's an excerpt from a post I made in this thread Question on huge size images

The image is 20122x11634 @ 450 px/in. The PSB file is about 3.7GB saved, and PS consumes around 7.75GB in memory while I'm working with it. So tilt's point is a good one - go with 2-3 times the amount of RAM relative to the saved file size.

So, bottom line if you're working with files larger than about 1.5GB, you will probably benefit from upgrading to 64-bit. Just be sure to keep in mind what Redrobes posted - you're entire system has to be 64-bit, the CPU, OS and the application.

That thread might be useful as it contains some good information about RAM, memory pointers, etc. And just about all the posts are referencing maps at the scale you were talking, 20k x 10k and up.