How do YOU create various resolutions of the same map?

[guyanonymous]

I write an app which is specifically designed to alleviate this issue. See sig. So naturally this is the way I do it. I don't have a fixed resolution image for the map.

Can you export the maps you create in viewing dale at full size (e.g., massive resolutions like 30000x___) or as tiles for use in googlemaps?

[Redrobes]

Can you export the maps you create in viewing dale at full size (e.g., massive resolutions like 30000x___) or as tiles for use in googlemaps?

In the app you zoom the map so that you get on the screen what you would like to export. Then you can export the screen image as a BMP, PNG, or JPG and you can set the resolution. You can set that as either a DPI with image size in mm or inches and it will calculate the pixel size or you can set the pixel size directly. It will make the aspect ratio whatever you had the apps main map window set to.

You can easily export up to about 20,000 pixels wide but as you go higher then it will start to struggle because of the limitations of the file formats and the PC memory required to render the screen image. Generally, whatever the app, I would say that about 10,000 is the max anyone should export images at. I have various apps which start to generate rendering issues after about 14K square. Gimp and Photoshop are almost certainly able to cope tho. Remember that if a pixel is 4 bytes then 20,000 square is 4x20x20Mb or about 1.6Gb of image.

There is no option in the app to export a set of tiles which line up in a grid but there is an option to import a large image and have it break it up into tiles and import it. So it will import 20,000 pixel images into it. Using arrays of images from tile commercial sets, I have imported a 100,000 pixel square bitmap into it. Its slow of course but it will cope with it.

There is a setting where you can request the map as an image over a web page interface so that you can get a web browser to view the image with the correct URL. In the URL is the X,Y, zoom and image size. If you got a script to ask it for a set of tiles of the map and changed the X and Y values and saved out all of the images then you could get it to make lots of map tiles that way. That's not a trivial thing to do but it could be done. If your looking to serve up the map to players using a browser only then you can note that the app has a map web server built in for that purpose. But you would not be able to host that on the net as a web page hosted by some web company. Your machine running the app would be serving up the map images.

For googlemaps or some other similar map serving java I guess it comes down to the requirements of the images it needs to build up the page. A quad of 20K square images would get you a pretty deep zoom image for a google map tiling app to run with tho.

[guyanonymous]

Redrobes,

Interesting. I really should check it out someday....it's only 'being stuck in the app' that's held me back since.

If I understand right, I can zoom out to encompass the whole map, export that at 20000pixels (or so) width, and it will include details that would resolve at that 20000 pixel resolution as though I'd had a 20000x____ window open and done a screen capture? (e.g., all the detail would be there)

I've found 30000x15000 or so is the max. size that compfortably works in -most- programs I've tried. Granted, I've not printed anything out that's 100 inches/50 inches, but you never know - I want to be prepared.

Do people need to own the viewingdale software to view the maps served on the web?

Thanks!

[Redrobes]

If I understand right, I can zoom out to encompass the whole map, export that at 20000pixels (or so) width, and it will include details that would resolve at that 20000 pixel resolution as though I'd had a 20000x____ window open and done a screen capture? (e.g., all the detail would be there)

That is correct. It is NOT like a screen capture scaled up to 20,000 pixels, its, as you say, as tho you had a 20,000 pixel screen so that detail which would be at the 1 pixel res is still there in the export. I had a video showing that somewhere. If I find it ill link it.

EDIT - Here it is:
http://www.viewing.ltd.uk/Temp/CG/VD...Demo1_xvid.avi
Its a bit long. Start half way through to see it save a 12,000 pixel image with 1 pixel detail.

Do people need to own the viewingdale software to view the maps served on the web?

Theres two modes of seeing a remote viewingdale map. You can a) use the VTT aspect of it where you locally generate the transferred map on your local copy of viewingdale. In that case you can modify the map locally and everyone gets the changes sent back. Its also super fast (realtime) scroll and zoom. For the VTT mode you need a copy. Or there is b) where you can set one master copy of viewingdale to act as a web server for the currently loaded map. In which case other people can use just a web browser only to request an image of the map at a set X,Y & Zoom and image size. In this case you can look at the map at different positions and scales but you cant edit it. You cant get a grid switched on or off or do very much. You just get an image. In a similar way that say google maps sends out tiles of maps to view but not edit. Note also this mode is served from the app not a web site. With your browser you need to ask for the image at your local IP address and do all the normal port forwarding for being a web server as opposed to normally being just a web client.

Using a combination of the two you can play the game with some people using a copy editing the map and have a couple of people using a web browser and they could use browser refresh to get a new image with changes made by the DM and other VTT players but he would have to request someone to move his characters icon.

If you have a static IP address and an always on windows box server then you could make web pages with links to your viewingdale web service so that you could have a wiki or a web based map and have links to map images which might change if you edited the map with the app. I.e. it would be a dynamic up to the minute view of the map areas without any need to FTP upload new static map images to a web site.

Hope that explains it.

[guyanonymous]

Thank you for the great explanation!

[sam]

Hello, a newbie here. I'd like to resurrect this thread.

Basically, I would like to use Google map API (or something that works similarly) to display both a country-level map,
and county, and then city-level detail. I made a largish map; and managed to slice it into tiles using the GMap Image Cutter.
The resulting Google map javascript-based API is very convenient. But even on my relatively small map,
the labels don't really work -- they are either too large or too small. Other problems have been noted upthread:
there is no feature discrimination, and roads (when I have them) and streams disappear at smaller scales.

Does anybody know a way to host zoomable maps on a generic web hosting site,
without a large investment in GIS software and data entry? Any pointers to further research would be welcome.