Celestia Forums

Hi all,

finally, I have finished my analysis of the Importance weight assignments, such that the location label density at any distance from earth remains constant. This avoids label overlaps to a large extent, despite the vast number of labels!

It is, however, worth emphasizing that one should really have ~ 32k VT textures installed in order to enjoy the amazing richness of this data base! 32k Nightlight textures are particularly important, allowing to precisely check the great accuracy of the label coordinates!


For people interested in the derivation, here is my HTML-converted and extensively commented Maple9 worksheet.

http://www.shatters.net/~t00fri/earth.html

The locations file with 41245 cities/towns may be downloaded from here:

http://www.shatters.net/~t00fri/earth-Gazetteer.ssc.zip

Enjoy,
Bye Fridger

t00fri wrote:http://www.shatters.net/~t00fri/earth-Gazetteer.ssc.zip

Oop. Error 404.

Grant

granthutchison wrote:

t00fri wrote:http://www.shatters.net/~t00fri/earth-Gazetteer.ssc.zip

Oop. Error 404.

Grant

Grant,

you started to download while I was still in an editing loop;-). Should be OK now.

Bye Fridger

t00fri wrote:you started to download while I was still in an editing loop;-).

Hey, I'm keen.

Grant

Wow!

This is really impressive.

Actually, there are so many labels that I am looking for a simple way to make them appear later (on KDE). Any Idea?

Harald

P.S: I guess someday celestia will be able to replace a roadmap

Harry wrote:Wow!

This is really impressive.

Actually, there are so many labels that I am looking for a simple way to make them appear later (on KDE). Any Idea?

Harald

P.S: I guess someday celestia will be able to replace a roadmap

Harald,

what do you mean with "later"?? Have a look at my derivation of the importance weights, which was most of the work. The result for the weights is certainly optimal for my 1600x1200 Moni and 32k VT textures. If you care to have my Perl scripts, you may play with the only free parameter yourself.

But anyway, I am not sure what you meant. What has KDE to to with all this?

Bye Fridger

Sorry for the unclear post, didn't really concentrate on writing

My problem was the screen getting too crowded with labels, I prefer them with some space between. So I admire the way you calculated the relative weights, but I like them more if scaled down by say 0.5 (which is what I just tried). Just a matter of personal taste.

Regarding KDE: I can't remember for sure, but I think the Windows version has a slider to control the required weight of labels (or somethink like this), so I wanted to mention I am not using the Windows version.

Hope this clears it up,

Harald

I would like to propose a very large vote of thanks in making your Earth-gazetteer ssc file available - I've been looking for something as detailed as this for some time. It's wonderful!
I feel I ought to point out that it is not without location errors, unfortunately (not your fault of course!)
Just skimming around my little country of New Zealand, I have noticed a half dozen places I am familiar with are in quite the wrong part of the country - there may be more as I'm not familiar with every little town in NZ...yet!
I guess someone typing in so many lats and longs, a tedious process, is entitled to make a few typos.
I'll be making my own corrections as I have access to detailed maps of the country on my PC. Be happy to share this info if anyone is interested.
cheers
Neil

Fridger:

I want to add my thanks for this contribution -- I am really enjoying the extra dimension it adds to the high-res virtual Earth textures. And the work you did with the importance weights really made the difference in usability.

Tim Crews

Glad to see that some of you also like that amazing locations file.

At present, I am still trying to improve on the somewhat too high label density (in Holland for example) in the range between

16000 and 100000

inhabitants. To remedy, it is just a matter of deforming my weight function a bit in that range of population.

Harry,

could you tell me what screen resolution and monitor size your are using?

Bye Fridger

guest wrote:I would like to propose a very large vote of thanks in making your Earth-gazetteer ssc file available - I've been looking for something as detailed as this for some time. It's wonderful!
I feel I ought to point out that it is not without location errors, unfortunately (not your fault of course!)
Just skimming around my little country of New Zealand, I have noticed a half dozen places I am familiar with are in quite the wrong part of the country - there may be more as I'm not familiar with every little town in NZ...yet!
I guess someone typing in so many lats and longs, a tedious process, is entitled to make a few typos.
I'll be making my own corrections as I have access to detailed maps of the country on my PC. Be happy to share this info if anyone is interested.
cheers
Neil

Neil,

I would be very grateful if you could let me know the 'mislocations' that you spotted in NZ!

If you do not know their precise coordinates, I can find them.

Thanks in advance,

Fridger

Howdy Fridger,

Finally got a chance to look at this file. WOW! This is one amazing file full of cities and towns!!! Looks like you did a real good job on it Fridger. This file alone is gonna give me hours of fun, looking at all the cities around the world. Thank you!

BTW, changing the FOV setting in Celestia also helps to split up the labels a little bit without having to go all the way down to 40 km or so.

Cheers,

-Don G.

Thanks Fridger
Here are corrected coordinates for the places in question

Hampden 170.81 -45.33 (was exactly coincidental with Murchison!)
Kaikoura 173.68 -42.40
Kaingaroa Forest 176.57 -38.40
Meremere 175.06 -37.32
Orewa 174.70 -36.58
Richmond 173.18 -41.34
Te Puru-Thornton Bay 175.51 -37.05 (Actually Te Puru, Thornton Bay is 2km south and is much smaller)

there may be others, these are the ones that leapt out at me!
want me to check the ones I'm not familiar with?
best wishes

Neil

Neil wrote:Thanks Fridger
Here are corrected coordinates for the places in question

Hampden 170.81 -45.33 (was exactly coincidental with Murchison!)
Kaikoura 173.68 -42.40
Kaingaroa Forest 176.57 -38.40
Meremere 175.06 -37.32
Orewa 174.70 -36.58
Richmond 173.18 -41.34
Te Puru-Thornton Bay 175.51 -37.05 (Actually Te Puru, Thornton Bay is 2km south and is much smaller)

there may be others, these are the ones that leapt out at me!
want me to check the ones I'm not familiar with?
best wishes

Neil

Neil,

thanks a lot for your active help! Things look much better already. If you are interested you should install the 32k VT Nightlights texture. Then you can directly see the cities&towns!

I am checking since some time with the help of my 'bible', the 'heavy weight' edition of the Times Atlas.

Any further help in sorting out the coordinates from your side is highly appreciated!

Bye Fridger

It is a great addon Fridger! I did not want to complain, but I did notice the high density in Holland too. Good to see you noticed it also... Am I Living in a very off-standard country?

Buzz wrote:It is a great addon Fridger! I did not want to complain, but I did notice the high density in Holland too. Good to see you noticed it also... Am I Living in a very off-standard country?

Yes and no it seems;-). Of course my mathematical derivation for minimal label overlap is based on the assumption of an idealized, homogeneous label( city/town) density on earth. Holland indeed deviates substantially. So all one can try, is to play some tricks here. This is still in progress...Apart from Holland, with my 1600x1200 setup, I have essentially very little label overlap remaining! Of course I can just "dilute" everything, but then one needs really huge zooms and hence huge VT tile sets to exploit fully the richness of the label data base...


Bye Fridger

Fridger

I've now checked all the New Zealand sites against a map. The ones below need correcting, everywhere else appears to be in it's proper place, without checking coordinates.

Te Teko 176.79 -38.03
Te Kopuru 173.92 -36.03
Waitara 174.23 -39.00
Waipawa 176.60 -39.95
Waitangi -176.52 -43.94 (changed longitude sign only - this is the Waitangi on the Chatham Islands, not Waitangi in Bay of Islands)

I wonder if other Celestia fans resident in other countries are checking their localities for misplacements. Be nice to eliminate as many errors as possible. Or am I opening a can of worms?
Will look at upgrading my nightlights texture, only running 8K at present
(speed tradeoff?)
cheers
Neil

Neil wrote:Fridger

I've now checked all the New Zealand sites against a map. The ones below need correcting, everywhere else appears to be in it's proper place, without checking coordinates.

Te Teko 176.79 -38.03
Te Kopuru 173.92 -36.03
Waitara 174.23 -39.00
Waipawa 176.60 -39.95
Waitangi -176.52 -43.94 (changed longitude sign only - this is the Waitangi on the Chatham Islands, not Waitangi in Bay of Islands)

I wonder if other Celestia fans resident in other countries are checking their localities for misplacements. Be nice to eliminate as many errors as possible. Or am I opening a can of worms?
Will look at upgrading my nightlights texture, only running 8K at present
(speed tradeoff?)
cheers
Neil

Neil,

many thanks! I'll enter the corrections right away into my source data file. Also within a short while, I shall release an upgrade...

You should look at Texture tiles (VT's). They work even with slower systems extremely well.

Bye Fridger

Fridger
Glad to help
Could I suggest you add Halfmoon Bay (Oban) on Stewart Island (the only settlement of note there, pop. about 400, coords 168.11 -46.90

Where would I find VT files? - I'm still a newbie here

cheers
Neil

Anonymous wrote:Fridger
Glad to help
Could I suggest you add Halfmoon Bay (Oban) on Stewart Island (the only settlement of note there, pop. about 400, coords 168.11 -46.90

Where would I find VT files? - I'm still a newbie here

cheers
Neil

Neil,

Thanks. I shall add this place, of course. NZ looks /much better/ meanwhile after your many corrections!

A number of VT's are mirrored here
notably the Blue Marble earth (32k!): bm_vtex.zip (92MB!) http://exp.arc.nasa.gov/downloads/celestia/extras/

As a precision reference for the locations, the 32k Nightlights tile texture is most useful:
http://www.shatters.net/%7Ejim/files/earthnight_32k_VT.zip

done by Jens (JIM). It's very nice independently of the locations and also not as big. On his site there are many more nice textures.

You have to search a bit here for instructions of how to install VT's.

Then there are also 32k NormalMap tiles. But I do not know where to find them. I made them myself, but only have a slow modem connection from home.


Bye Fridger