Numerous overlays

[ATTILA]

hello,

Due to lack of Hi-res maps for France, I'm working on a piece-by-piece hi-res overlaying for every workcrafts of the French Maginot Line...

Well, as you may know, this is supposing more than 1800 overlays (!!!!).

Even with the smallest size (640x400) i'm now stuck at the 1srt quarter of the project with unavailiblity to load more than 2 complete sectors (nearly 350 overlays) out of 23 existing to be done.

All of these files are therefore on an external FTP server for it was impossible to upload the final KMZ directly on GEH when they were GEH "residents".

Is there any solution to bypass this ? For, if someone clicks on the "general" button instead of opening sector by sector, GE freeze and has to be "killed" then reloaded.

Of course, i can make 23 independant files (why not?) but that won't solve the hereabove problem if any wants to have a look at the whole Line.

thks in advance for any advices

ATTILA

[Forkboy2]

I'm not sure I understand, but I think you might need to use the Region feature which will automatically turn on and turn off overlays. You can read more about Regions here.

http://earth.google.com/kml/kml_21tutorial.html

Matt

[ATTILA]

Hello,

Many thks, this seems to be the right solution even if it's some kind of a hell to set up properly without any specific tool (i'm not very friendly with scripting)

Loading of overlays remains a little bit long but it seems to works nice and clean... i'll hope it will still be steady as far as the job will get on !

thks again

[Forkboy2]

Hello,

Many thks, this seems to be the right solution even if it's some kind of a hell to set up properly without any specific tool (i'm not very friendly with scripting)

Loading of overlays remains a little bit long but it seems to works nice and clean... i'll hope it will still be steady as far as the job will get on !

thks again

If you just use one layer of Regions, then it's not that hard to set up. Simply add the following for each overlay that defines when the overlay should be visible.

<Region>
<LatLonAltBox>
<north>????</north>
<south>????</south>
<east>????</east>
<west>????</west>
</LatLonAltBox>
<Lod>
<minLodPixels>128</minLodPixels>
<maxLodPixels>-1</maxLodPixels>
</Lod>
</Region>

This will automatically turn on an overlay when it nears the center of your view and turn them off when outside of your view. This lets you use an unlimited number of overlays.

Nested Regions (ie Super Overlays) are a lot more difficult, but may not be necessary, depending on the desired resolution of each individual overlay.

You can find several examples here http://www.topomaps.fox-fam.com/index.php

Matt

[ATTILA]

Hi,

I do understand what can be done, but i think that my purpose is much more looking like Nested Regions as far as i need:

1 General region (Ligne Maginot) including :
4 Main regions (R.F. xxxxx), each of these including
6 sub-regions (S.F. zzzzzz), each of these including up to 380 overlays.

I want to be able to load the general region (as well as the main regions) and see only all the placemarks whatever Altitude and pixel definition is but without any overlays details.

The overlays should only be loaded when accessing the 3rd level (i.e sub-regions) and refreshed when accessing a new sub-region.

The Kml file is more than 58.000 lines, that's why i'm talking about "...some kind of a hell" and looks for help.

By the way, the previous test done with "flat regions" (1 level only) is not stable. It is working fine with 2 regions but it freezes again at the mid 3rd region ...and is very ,very, very long to load before crashing.

O great God of G.E.... why haven't you set up High-Res for France (joke)

ATTILA

[Forkboy2]

What is the resolution of the 380 overlays? That will determine how difficult your project is. If they are less than around 1,000 x 1,000 pixels than should be pretty easy. If they are greater than that, then you may need to cut them up into smaller tiles, and thats where things get complicated very quickly.

Not sure what problem you are having with GE freezing. My guess is your overloading video memory by trying to load too many high resolution overlays at the same time.

Matt

[ATTILA]

Hello,

That is exactly the problem for "freezing"... all of the overlays seems to be loaded all together when the General view is opened. It seems to stay "cool" only when accessing directly a sub-region immediatly after opening the main file.

Therefore, my machine is a 4Gb RAM with 512Mb dedicated video.

Each of my overlays are 640x480 pictures (all the same size). 380 overlays is only for the "biggest" sub region (not yet placed), usually other sub-regions are between 70 to 230 overlays.

Just by now, there are only 870 overlays placed in the new file i'm trying to get steady and i won't go further on before this is solved

Perhaps should i say that every single placemark of this file has its own overlay (plus photo and map when available)... Should these additional parts be considered as overlays in RAM point of view even if placed in the "description" part of the placemark?

[Forkboy2]

The code I posted above should work quite for the 640x480 images. Just add the region code to each KML entry and the LOD settings will automatically turn on the overlays when they are in view and turn them off when they are not in view. That should solve your problem with locking up.

I don't think the info in the placemarks matters since those would only load if clicked on.

[Captain Hornblower]

Attila, I hope you don't commit suicide, when GE updates the areas you've covered with your overlays ;)

[ATTILA]

Hi,

Well thks for help and let's go to place all codes...It'll take some time.

By the way, no scheduled Suicide... just by now but to be sure not to jump the cliff, the job has been done in "twin mode", I.E. with AND whithout the overlays, so when GE will be upgraded to Hi-res for France, i will only have to place the second file...

Once bitten..twice etc etc .....