Google Earth Plugin

[nohal]

Tore,
have been observing Paul's tool evolving just from a very long distance. Will have a closer look at it when time allows.
Saving a screenshot of GE window is possible with the API, BUT - the citation from the documentation of that function:

Takes low quality black and white screen shot of the current camera view.
This image is not meant to be used for rapid capture and degrades in quality if used frequently.

Looks like Google doesn't want us to do that to me

One question: how does this cope with larger areas (way bigger than a harbour plan), far from the equator, where the difference between GE's spherical projection and Mercator can (and will) get enormous? Are the corner coordinates good enough to calibrate the picture? As I've calibrated quite a few charts myself and tried to do so with some satellite imagery as well, I'm pretty skeptical here...
But you are the experts in this area

Pavel

[sinbad7]

Pavel..

The bitmaps saved from a GE display becomes no less than the original and has all the colours. See attached Genova.jpg and Genova.kap screendumps.

A GE image is usually only required for detailed close-ups of ports and approaches and would never be used for large zoomed out areas which could affect the calibration.

GE2KAP requires that a bitmap of the GE display has been saved to it's directory.
It then searches for an active GE window and grabs it's geo co-ordinates and makes the conversion to a .kap file.

It could also easily be made to accept a .kml input to create the .kap file.

It would be most convenient for the user to do the whole thing 'on-the-fly' while already in OpenCPN with an active GE plug-in.

Tore

[nohal]

Tore,
can certain borders for the usability of such a function be defined?
Some are clear, like tilt 0 degrees but can we choose a reasonable limit for for example camera height where an autocalibrated chart is "safe"? Is it dependent on the latitude?
Evaluating the options to approach this problem. What I definitely don't want to do is make it easy to produce "charts" that are totally inaccurate... It could easily turn into a nightmare.

Pavel

[HappySeagull]

Originally Posted by nohal

Tore,
it stores SOME of the places you have visited before. Probably the last ones + also probably a very low scale version of the whole globe. The logic is Google's secret. In no case all the globe - not even you have disk of that size

The places that are in the cache work as if you were online.

And yes, I've tried and replacing the cache with another one I've saved before works (you have to do it when GE or my plugin are not running of course). The GE Voyager documentation is very good source of info on how it works.

Pavel

I've spent a few hours making google earth chart kaps and your plugin will make em all redundant when Internet is as ubiquitous as GPS.Everywhere-All-the-Time ! Curse You!

I haven't had much luck with cache storing since I upgraded GE to 5.1. With earlier versions,I could switch 2 gb "magazines" quite well.But this newer version cache never seems to fill up...I'm just now trying GEVoyager you mentioned.

I tried your Plugin offline and it is reading the incomplete cache but never settles...Likely because I don't have ALL the tiles in the cache needed per various altitudes ?
...couldn't find any difference per directx or open gl or colour depth etc. but it's a thought for other testers...



I do notice tweaking works better if I turn off GE Plugin before tweaks!

[nohal]

Originally Posted by HappySeagull

I haven't had much luck with cache storing since I upgraded GE to 5.1. With earlier versions,I could switch 2 gb "magazines" quite well.But this newer version cache never seems to fill up...I'm just now trying GEVoyager you mentioned.

Have you tried reducing GE's memory cache to say 16MB? On my dev system with 4GB of memory it defaults to 500 megabytes, which could probably store all the tiles downloaded during a normal GE session. The caching strategy of GE is a bit of a mystery and sure needs some more exploration...

Pavel

[sinbad7]

Pavel..

If you feel so concerned about the outcome that you have to restrict the type of bitmap saved then ok, o tilt and North up is ok and some kind of combination of map corner limits and eye height could be imposed. Why not just include a rider stating the limiting parameters/scope of the map produced? You can easily check the accuracy of .kap maps produced but they are only secondary maps supplementing 'real' maps and must be used as such. The great convenience being that you can display them in OpenCPN.
All the .kap map headers usually bears this warning:
! Created by mc2bsbh beta07 - Use at your own risk!

Tore

[sinbad7]

Pavel..

I really do'nt see any problems if all YOU provide is a way to save a GE display as a .jpg file. What anybody later uses it for is not your responsibility. There are several utilities around converting bitmaps to .kaps and they do not impose any restrictions.

Tore

[sinbad7]

Pavel..

The easiest thing would be to just let Google Earth's own command CTRL-ALT-S be included in the GE window as you have done with the zoom and view angles.

Tore

[HappySeagull]

Originally Posted by nohal

Have you tried reducing GE's memory cache to say 16MB? On my dev system with 4GB of memory it defaults to 500 megabytes, which could probably store all the tiles downloaded during a normal GE session. The caching strategy of GE is a bit of a mystery and sure needs some more exploration...

Pavel

Ok,I'll have another go re:16mbVS cache fill...Thanks for recall,I DID read that in your post earlier and was going to try it but it slipped off the scope with GEVoyager try!...

By the way,and not to sweat.I wonder if GEVoyager bites your plugin....somehow?I ended up with weird borders and pulsing-zoom behaviour on GE_Plugin after following GEVoyager's setup directions and even when it's KMZ|KML whatever was Unchecked/deleted from GE's sidebar. cache confusion maybe...just mentioned as it may relate to others posts previous?etc.
I fixed it somehow. I managed to get GEPlugin back correctly after resetting the GE to its defaults and disable,re-enabling GEPlugin etc....
Also,
Do you have a "Recommended" double check of Optimum Settings in Google Earth...things to avoid screwing with the GE Plugin?
Ohhh, the bleeding edge!thank goodness I'm a lightweight critter!

[nohal]

It's impossible to run GE, and the plugin at the same time because of GE's design. It's a bit too techie to explain, but although the plugin uses just the globe view part of GE, all the rest is running in the background and can make the view a mess while fighting for it with OpenCPN and sending it completely different commands. The same is causing the weird behavior for example when you doubleclick a KML/KMZ file while running the plugin.
The same if GE's set to receive the "networked" KML from the Voyager...
Impossible or at least very hard to do something about it on the plugin side as it is a problem in GE itself.

Pavel

[HappySeagull]

No,no.Not quite what I meant...I only run one at a time.Windoze 98 made me BlueScreen Phobic!...No,I'm working on the theory(right wrong?) that GEPlugin is necessarily? using whatever GE has in it's "Options/settings" so there's a lot of on-off of each happening per any experimenting I'm doing....
mmm,I figured that per Voyager...

By the way,the 16mb cache is helping,I think.I just grew it from 145mb(where it's been stuck) to 185mb so things are looking up.And it didn't shrink on repeated bootups of orphaned Google Earth!There's hope then and I 'll be able to run GE Plugin without Internet as you said...!
Cooler and Cooler! but I think I'll save the Voyager for when the herring aren't jumping like they are here!

[sinbad7]

Pavel..

To prove the accuracy of a .kap map generated by GE2KAP from a GE display,please study the attached screendump and note the geo locs of the mark dropped at the grid intersection against the pos report in the status bar. It's 'bang on'.

Also please note that running consecutive .kml files replaces each new display in GE without starting multiple GE's. This is NOT the case in the GE plug-in.

I would very much like to also have available the standard GE key command of CTRL ALT S in order to save the display as a .jpg file. Possible?

Tore

[nohal]

Tore,
when you click a .kml file with the plugin running, the only thing that happens is that the hidden parts of GE GUI that the plugin requested to be hidden get shown, but the display part stays where the plugin placed it (part of OpenCPN GUI). That's a bug in GE and can't be fixed by me. This bug simply doesn't reveal itself when you are using GE as a standalone application.
For the harbor plan with a scale shown on your screenshot I'm not concerned, the accuracy will be acceptable - especially around the center of the screen, my concerns are for bigger areas (worse if placed further north or south) - there I think we should set some reasonable limit when even trying to calibrate, especially automatically, makes very little sense.
Ctrl+Alt+S impossible as we are in the plugin and can't influence the keyboard handler currently, but saving screenshot as JPG should be possible.

Pavel

[sinbad7]

Pavel..

Ok,so you are saying that whilst executing .kml files directly in the GE interface is no problem,it can not be done via the programming interface. That's a pretty serious bug in GE I think.

Well,that means we can not use the GE plug-in to call up previously saved images and have instead to call up GE separately.

As I said,GE maps wil in 99% of the cases be created to view zoomed in harbour areas.

Tore

[nohal]

Tore,
no, never said something like that The bug in GE is it shows the useless rest of the window while the plugin is already running.

Pavel