Google Maps API - What I've been working on.

[RPMiller]

NICE!!

You definitely have it now. The tiling at zoom 0 is odd, but understable to allow for a sphere. If only there was a way to get the better pic exports...

Everything else seems to be working smoothly now.

[Robbie]

As for the weird tiling: go to maps.google.com and zoom ALL the way out. You'll see the exact same effect, only with our earth. Unfortunately I didn't map the stretching at the poles and google actually handles that in its map coordinates.

As for the weirdness in the export of the images...the text being choppy and things like that actually is how the png originals turned out. Now, I imagine that if I used a different less flashy font, it would probably be easier to read, but meh...I'm not really worried about it too much since this is just a proof of concept at this stage.

[Robbie]

BTW...those 5 zoom levels all add up to 14 megabytes...bleh. Thats all at jpeg quality 6. 12 is maximum quality.

[RPMiller]

I wouldn't worry about the size of the files myself. There was a time when I would be concerned about those with slow connection speeds, but in this day and age I would give a warning that broadband is required and be done with it.

[Intermagus]

I have to agree with RPMiller....a broadband connection is quickly becoming the norm instead of the exception, plus the idea that since these maps are tiled, which will load the first tile zoomed into and work its way out, will be very little wait time for viewing the sections of the maps as needed.

My largest map is my Kalam worldmap, at 7000 pixels wide by 3000 pixels tall. It's a PNG image and at last check was a 60+ MB file. Will I be able to use this one once it's also been sliced into tiles after the interface for this mapping becomes available? Ideally, I am aiming for city street level viewing in the same map as would also be available to view the whole planet, hence the massive file.

*edit* Oops.....I forgot about the "monster file" I made a year ago, sitting in my other maps folder. That bad boy is a pixel per mile file, 26250 by 11250, and still not street level (which by my estimates would require at least 1 pixel per 20 feet to make the street level view able to be recognizable). 866 MB PNG file. Now we're talking ACK. But that's with no compression at all.

[Robbie]

Well, given the way the Google API is designed, all of what you say is possible...Whether or not I'll be able to provide a simple way of doing something like that without SOME level of user scripting is a different question though. Also, storage space isn't really a concern for me I don't think, but hosting bandwidth could become a concern eventually. If I were to start hosting map tiles (become a map tile server) I'd need to generate some additional ad revenue in order to afford the bandwidth costs of running something on that scale. Like I said on the CC2 List...I don't want to make any promises at all, but This looks very promising for the world of game mapping. Google maps go down to the street level, reasonably this could too. BUT...you wouldn't want that much detail for the whole world at every possible zoom level. Just like certain areas of the Google maps world aren't available at closest zoom, neither would your super-large world map.

The biggest concern would be lining up your street level zooms with the previous level of zoom, and so on and so forth. Of course you'd probably want to start at the widest view and work your way down. Remember the chart I posted previously that lists the pixel size and tile count all the way up to Zoom Level 7? Well, If I'm not mistaken the API currently supports zooming in all the way to level 17. I'm not willing to do the math, but thats a helluva lot of pixels.

[Intermagus]

Considering the calculations, the farthest zoom is well within the parameters of even my monster file map. IMO if the larger the map, the less details per pixel required and therefore a much lower file size/higher compression needed for each level of zoom-out. Compression/detailing of the individual tiles would be easier, unless the API can use only the 1 whole file (which doesn't look like that's the case from what I'm reading here).

[Robbie]

No it can't use the whole file, it has to be chopped up and "served" accordingly. Each tile is named according to its position in the map. For example the tile I linked to previously (and subsequently renamed after I redid the map) is 13_8_4...meaning its position is x:13, y:8, zoom level 4. The google api allows for code to call those tiles from a tileserver or host directory based on a formula.

I think in your case it would be unreasonable for you to detail every square mile of your world down to the street level. BUT it is possible. Google doesn't detail every square mile of our world down to the street level, but they've sure done a lot of it.

For every 1 tile at zoom level 4, there's 4 tiles that represent the same area at zoom level 5. So every zoom level doubles the amount of space available to show detail on a particular area. Should an interface be built that allows maps to be automated, a tool would have to be built (or duplicated) that allows smaller maps to be lined up with the appropriate area at a previous zoom level. All logistical issues that I'll be trying to work out.

In the meantime...it appears that since I have moved the demo to the Cartographers Guild site template, the page is not viewable in IE. I'm trying to work out that issue right now. (EDIT: Fixed for now)

[RPMiller]

So basically each zoom level has its own image, and then that image is sliced up. So for instance if I wanted to do something similar to Intermagus, I would start with the way my world map from FT looks lets say, then I would turn on the various layers to display more detail and save that as another file but with a higher resolution. Rinse and repeat. Is that correct?

[ravells]

Superb!!!

i suspect the 'how do to it' bit will be completely beyond me though!

Ravs