Google Earth Plugin

[nohal]

Tore, but WHY do you want to open the kml file and why do you want to do it in the plugin without the map reflecting the same? That's what I don't understand at all. Why don't you just use the normal OpenCPN facilities to get to a place? Don't you have waypoints and routes when you navigate somewhere?

Good that you found the processes tab in Taskmanager I was sending you to in my posts.

KML never contains any images or stuff similar to them, it is a XML (=text) file telling GE where and how it should move the camera and which features to add to the view.

Did you read my last post until the end? GE has the ability to show something without a connection. But this something has to be in the cache = you must have seen it before when you have been connected. How long it stays in the cache and how much stuff fits in is hard to say. Some info for example at Offline Google Earth Use | Google Earth Blog

Pavel

[sinbad7]

Pavel..

I think I have probably navigated my ship before you were born,so cool it!

All normal programs in use are as a rule listed in the first box of the Task manager,so I looked no further,GE being somewhat special was located in the second,processes tab.

There must be a way to store a GE view for later display in OpenCPN independently of internet connection.

You are asking WHY I'd want to view a GE image of a port I am planning to visit when I have charts,waypoints and routes? You're missing the whole point of a GE port view,
It relays information you do not see on a chart,you may not HAVE a chart of certain areas and a GE view is better than none,furthermore you can study your arrival port from several directions and elevations. I would have thought that would be obvious...

It's only suggestions...you're the boss....

Tore

[nohal]

Tore,
sorry, I did not want to sound rude, but please open any kml file in a text editor (any) to see what's inside it.
Then you will see what I'm talking about all the time. There are no images there.

Pavel

[sinbad7]

Pavel..

I'm perfectly aware of the contents of a .kml file,I sent you one to look at...
It is of course totally dependent on GE to display areas.
There must be some other way to capture a GE display other than a .jpg screen capture for subsequent reference off line? This is the whole point I'm making.

You can also go the other way from one of my loaded GE displays. Use the geo refs of the GE display to copy and paste into OpenCPN's 'Jump to position and you also have the map display.

OK,presently it is only possible to use the .kml files when connected to the internet but I think someone mentioned that GE also can communicate via GPS?

Tore

[nohal]

Originally Posted by sinbad7

I'm perfectly aware of the contents of a .kml file,I sent you one to look at...
It is of course totally dependent on GE to display areas.
There must be some other way to capture a GE display other than a .jpg screen capture for subsequent reference off line? This is the whole point I'm making.

I'm afraid there's not. Well, maybe video could be done as well, but certainly it's not what we would like to have. GE works like a public library, what we can do is pick up the phone, call it's number and ask if it can send us the book we need. It will or won't, but there is no way to know before we call and if there's no book, we can't get it.

You can also go the other way from one of my loaded GE displays. Use the geo refs of the GE display to copy and paste into OpenCPN's 'Jump to position and you also have the map display.

Of course, but converting the KML to GPX and importing the waypoints and routes it contains is much easier.

OK,presently it is only possible to use the .kml files when connected to the internet but I think someone mentioned that GE also can communicate via GPS?

You don't have to be connected when you want to use them. But to get any useful imagery, it has to be in your local cache when you're offline, so you have to connect before you set sail and "visit" the places where you are going to need the GE data.
The annoying part of things is, as you said, that GE is the one deciding what it keeps in the cache and for how long and there is no way to even know when certain data get discarded. Most likely the bigger you set the size of the cache in the config of GE, the more data fits in and the longer they stay.

GE can get the position from the GPS, but not the imagery unfortunately.

Pavel

[sinbad7]

Pavel..

Here's an interesting item about our topic..;

[nohal]

Tore,
exactly. The cache can be quite easily transferred even between machines and you can swap different caches on the same machine (while GE is not running). But as it is impossible to know, what's inside any of them, this has to be done manually as we can't tell whether just Ushuaia-Puerto Williams fits in or whether it will be good all the way to Lennox. The only way to discover it is by disconnecting from the internet and having a look.
And of course the caches are HUGE - gigabytes of data, so even just copying such files takes minutes.

Pavel

[HotRod]

Just a few bugs that I found:
1. Mouse wheel zoom is deactivated and cannot be activated while GE is activated.
Mouse wheel zoom works for GE, but not for OCPN.
2. When closing GE view and opening it again it resizes to default width, this causes the GE picture to swirl constantly.
3. When opening OCPN it would be nice if GE returns to inactive as default.

[nohal]

Guys!
Version 0.2 beta of the GE plugin is available

Changes since the 0.1 beta:
- The plugin starts GE at the time it's needed for the first time, not while the plugin is loaded by OpenCPN
- Added config option to always start hidden, ignoring the state when OpenCPN was closed last time
- Added the possibility to save the current view as .kml file to be used in GE directly.
- GE now scrolls to the needed position requested by OpenCPN instantly
- Added a lot of debugging output written to the log
- Fixed all the crashes I've experienced on my system
- Mouse wheel should be returned to OpenCPN in all cases besides the one described bellow

Known problems in this version:
- Disabling the plugin in toolbox while it's window is open leaves the pane on screen
- Toolbar icon state on enabling the plugin is wrong
- We should handle "intelligently" the case when the GE view parameters are changed by the user, not reset it to the config settings on every update
- Plugin window size resets to default when it's reopened
- AUI code generally needs a bit of a rework
- Camera tilt and azimuth don't work in follow cursor/boat mode

Important note for GE offline use
GE tries to connect to the internet on startup and if it's not available it waits for some time (about a minute on my machine), hoping the connection will come alive. There is nothing that could be done about it, so you have to be patient waiting for the plugin to start in this scenario. After another while, GE displays two dialogs telling you, that there's no internet connection and whether you want to troubleshoot the problem. Answering No to the question is the thing to do. Unfortunately while displaying these dialogs, GE "steals" the focus and mouse wheel events don't get to OpenCPN anymore. To reclaim the mouse for OpenCPN, resize the GE plugin view a little bit and you are set again. This is inconvenient, I know, but currently I can't find any other workaround.

Populating the GE cache for offline use
Google Earth is designed with a permanent highspeed connection to the internet in mind, but can be used offline if the necessary imagery data is available in the local cache on disk.
To make the data available locally, it's necessary to visit all the places we want to see before the computer is disconnected from the internet.
Fortunately we are not the only people facing this problem and several tools exist, helping to simplify this process. Probably the best for our use is GoogleEarth Voyager - read about it and find the download links at Google Earth Caching Programs III
GEV comes with a comprehensive documentation covering the whole problem - definitely worth reading to understand what's going on.

Installation and usage instructions
It does NOT work with OpenCPN 2.3.1 as it relies on the API extensions introduced in version 2.4

Before you use it:
- Make sure you are using Microsoft Windows. Sorry, there is no chance to get this running on any normal operating system
- Download OpenCPN, version 2.4.0310 beta from Download OpenCPN | Official OpenCPN Homepage and install it
- To make the view sizing work reasonably, run Google Earth and turn off the toolbar and the sidebar in the View menu or Ctrl + Alt + T and Ctrl + Alt + B respectively
- Download the attached file gecomapi_pi.doc, change the extension to .dll and place it into the plugin directory in your OpenCPN installation

Run OpenCPN, go to Toolbox and enable the GE plugin on the Plugins tab
The plugin icon appears in the toolbar

Report back your observations

Pavel

[hoolie]

I've been using your plugin without problems, starting up or running. A couple of observations.

I am not keen on having 2 docked windows side by side as I prefer to overlay the GE image over CM93 charts.

I am using autohotkey on Windows 7 to make the GE window semi-transparent (180) and I can easily adjust the scaling and positioning to match the chart underlay. This works fine with internet access but I have also used Paul Higgins excellent routines on this forum to produce BSB chartlets from GE of places we're likely to visit without needing internet access.

All excellent stuff and much appreciated - thanks for all your efforts!

[sinbad7]

Pavel..

ver. 0.2 is looking good!! No crashes this time..and the save .kml file is great.

I see no way to load (display) a saved .kml file and clicking the .kml file brings up a new screen on top of the old GE display. Could it not REPLACE the previous screen?

I overcome the problem by first switching off the present GE and then clicking the required .kml file which starts GE and displays the selected area. I had to hold down CTRL while clicking the minimized OpenCPN and then right click it to create two screens.

Thanks for the improvements and a good installation guide.

Tore

[HotRod]

Will you make it multilanguage capable any time soon? With .po and .mo files I mean. Just like the rest of the plugins...

[nohal]

HotRod,
it is multilingual from the very beginning in exactly the same way as the other plugins. I'm just not distributing the localization stuff with the testing versions and it would be a waste of time to translate it before it stabilizes a bit more feature-wise IMHO. Right now the GUI is very small - roughly 20 strings and if it grows a lot, it will be 50, so the translation will take something like 5 minutes...

Pavel

[HotRod]

I mentioned earlier, when running OCPN fullscreen and docing GE, it goes totally bananas. Zooms in/out and swirls around. Happened with the previous version and also in the new v0.2
If I run OCPN in a smaller window, it settles down.
I run OCPN on a 26" monitor @ 1920x1200...

[nohal]

Originally Posted by sinbad7

ver. 0.2 is looking good!! No crashes this time..and the save .kml file is great.

Very good news!

I see no way to load (display) a saved .kml file and clicking the .kml file brings up a new screen on top of the old GE display. Could it not REPLACE the previous screen?

Unfortunately not. The plugin uses just the display component of GE, but the GE application is still associated with .kml files (and it's probably good).
GE is unfortunately not at all designed to be able to run twice at the same time on the same system and that it starts when you double-click the .kml file while the plugin is running is actually a bug in GE's logic (which they will probably never fix as the API is currently abandoned by Google)
I'm still not decided how to implement this stuff. To make it correctly, we have to extend OpenCPN's plugin API a little bit. Have to talk to Dave about it, but as the extensions I would need will benefit a lot of other possible applications and are not that much of work, I think it can be done.
Right now there is a simple workaround you can use - just drag your KML file with mouse and drop it on the GE plugin window and it will be loaded. The drawback is, that in the current version it will stay there just until the plugin gets a new event from OpenCPN. I have some ideas how to handle these situations. In the next version later this week there will be some preview.

Pavel