KML Overlay Plugin

[SethDart]

Originally Posted by Gilletarom

Now it remains to add a slider to change on the fly (without returning to the toolbox), the level of transparency.

That's really not the purpose of this plugin (viewing vs. editing). Each KML object has its own parameters for transparency and they are used in the plugin (border transparency can even be different from fill transparency). If I was to use the same transparency for all (even user set), that'd be a big miss IMHO. Or it'd require a slider for each KML object (remember, kml is a container, it can contain several objects). The current way, you can have some objects transparent, some opaque, some more transparent than others. To me it's the best way. You can change transparency level very easily in GE and see the result in OpenCPN ; repeat that until it fits your needs.

Regards,
Jean-Eudes

[Gilletarom]

Hello SethDart,

Originally Posted by SethDart

Dirk, can you try this one:
http://je.onfray.fr/dl/kmloverlay-test_pi.dll
It requires one more dll in OpenCPN root (same as expat.dll)
http://je.onfray.fr/dl/zlib1.dll

Crossing fingers... ;-)

I removed the previous version (including the other associated dll) and charge thereof.

I did not see her in the plugin manager

I added the file expat.dll and it works. but then, your window is left hanging. See screenshot.

[LeaseOnLife]

Originally Posted by SethDart

Warning: transparency only works with OpenGL enabled.

Are you sure?

• I disabled OpenGL
• restarted OpenCPN
• used Gilletarom's kmz

seems to work on my desk


Dirk

[Gilletarom]

Hello,

Originally Posted by SethDart

.... Each KML object has its own parameters for transparency and they are used in the plugin (border transparency can even be different from fill transparency). If I was to use the same transparency for all (even user set), that'd be a big miss IMHO. Or it'd require a slider for each KML object (remember, kml is a container, it can contain several objects). The current way, you can have some objects transparent, some opaque, some more transparent than others. To me it's the best way. You can change transparency level very easily in GE and see the result in OpenCPN ; repeat that until it fits your needs.

Jean-Eudes

It is impracticable.

It would, for the same area, have, at sea, where it is needed, several kmz different from each other. The essential difference is the level of transparency. This will ask a considerable amount of work prior to shipping.

We need, for a given area, a single kmz, acting as a chart. This kmz be posted with a transparency rate adjusted on the fly with a slider. And one slider would, he would act on all kmz displayed simultaneously on the screen OpenCPN.

That said, unable to write the program, I may be pretentious to say this. That said, again, I guess, technically, it is possible to display two images overlaid and one of them can be with a certain transparency coefficient (coefficient chosen at time of posting of or my idea of slider)

Cordialement

Gilletarom.

[Gilletarom]

Hello,

Originally Posted by LeaseOnLife

Are you sure?

• I disabled OpenGL
• restarted OpenCPN
• used Gilletarom's kmz

seems to work on my desk


Dirk

I confirm that it work with OpenGL and without OpenGL

[HappySeagull]

Originally Posted by LeaseOnLife

It loaded, I see it in the Plugin Manager, no errors in the event log.

More testing to follow ...

Thanks!

Dirk

double thanks,Seth-Dart! Works here too!

[SethDart]

Originally Posted by LeaseOnLife

Are you sure?

• I disabled OpenGL
• restarted OpenCPN
• used Gilletarom's kmz

seems to work on my desk


Dirk

Yes I am... I wrote the plugin ;-)
I'm talking about polygon / lines and basic kml features. Fortunately, as you noticed, GroundOverlay transparency should always work.

[LeaseOnLife]

Seth...

now, that some of us are over the first hurdle with this plug-in, what is next?

I find the procedure to get a GE image into a Ground-Overlay too cumbersome to be done multiple times.

In contrast, GE2KAP has a good feature: a way of semi-automatic capturing and geo-referencing the GE screenshots. But I like your idea of using transparent kml layers better!

Do you envision to come up with some way to help creating the Ground-Overlay? Maybe from within Opencpn, using the GE plugin from Pavel/Nohal?

Cheers

Dirk (the Insatiable )

[SethDart]

Well, a few things:

KML is not limited to GE. GE can produce KML/KMZ files but others tools can do so.

KML/KMZ is not only for chart overlay, it could be used for NTM (notice to mariners), user defined drawings on chart. Some of the layers from Layers Library | Official OpenCPN Homepage could swith to KML. As already suggested, pilot charts could be more usable as KMZ (and probably a lot lighter, maybe split in smaller parts).

FYI, this plugin was requested by French Navy for use in search and rescue boats (SNSM, equivalent to RNLI in UK) They wanted a tool to display a search zone over charting software. The zone is a KML polygon, with maybe a few lines and some points (last known position). I've created a special version of this plugin for them which automatically load kml files from a selected directory. This directory can be populated by MRCC, remotely via 3G connections with special tools from their own. I added GroundOverlay as a supplementary feature, say: "the icing on the cake" ;-) Because I thought it could be very usefull to lots of us.

Now is time to find tools that can create such ressources. Maybe create some of them. To me, that's not the purpose of this plugin. This is not just another GE to OpenCPN plugin. It's a KML/KMZ overlay plugin. Period.

One solution to your request would be to have some GE2KML (or better KMZ) tool. Can you ping the people behind GE2KAP to see if it's feasible?

Edit: jut to be clear, I did all this for free. That's my contribution to their amazing job

[Gilletarom]

Hello Jean-Eudes,

In any case, even if your plugin is not doing what I dream, just to have served the lifeboat, thank you.

Amicalement,

Gilletarom.

[LeaseOnLife]

Originally Posted by SethDart

One solution to your request would be to have some GE2KML (or better KMZ) tool. Can you ping the people behind GE2KAP to see if it's feasible?

Ping sent, post 579 in this thread:
http://www.cruisersforum.com/forums/...tml#post923708

Please add comments if my description is incorrect / incomplete


Dirk

[phiggins]

OK you've hooked me on this.

I can modify GE2KAP to produce a KML (later KMZ) file with the coordinates and an image file rather than a chart.

Here is how it would work:

1. Start OpenCPN and display the area that you want to make the KML/Image for.

2. Start GE2KAP and sepecify in the output directory the directory and file name with a .KML suffix rather than .KAP.

3. In the input field enter "opencpn".

4. Press "Create Chart". GE2KAP will then a snapshot of the OpenCPN screen and overlay it on GE. You can then adjust the transparancy to show both the GE display and the chart information.

5. Then press OK on the GE Image overlay screen. GE2KAP would then produce the KML file and the image file.

6. Then use the KML/KMZ plugin to display the image on OpenCPN.

You could also specify the area by creating a route in OpenCPN around the area and saving it as a GPX file. Then in GE2KAP enter the GPX file as input and it will use it to display the area on GE and create the KML/Image. But you don't get the chart information as you do with the above method.

How does this sound?

[LeaseOnLife]

Hi Paul

thanks for having a look here!

I think you are a few steps ahead of me

I was thinking of something much simpler:

1. I would like to be able to use GE or OpenCPN to select an area I want a GE-screenshot of.
2. GE2KAP then takes a screenshot of the GE image only, not of any chart.
3. GE2KAP creates a kml file, containing the just the satellite image with the needed data for overlaying.
4. KML overlay can then overlay the GE image over any chart (Raster or vector chart, any scale...etc) in OpenCPN.

Other thoughts:


Transparency: The samples I have seen show the "Ground layer" as a transparent layer over the chat. I am not sure who/what takes care of making the image transparent, and to what degree.


Grouping if GE images. Right now I can only select a file in the KML overlay plug in. If I want more than one image in a given kml file, I probably have to do some voodoo within GE.


For me, it would be most important to have the satellite image separately from the chart, not stored as an overlay-ed image. I like to have the flexibility to chose a satellite picture overlay, then change the chart underneath.


Would this be a direction to go?


Cheers


Dirk

[phiggins]

I was thinking of something much simpler:

1. I would like to be able to use GE or OpenCPN to select an area I want a GE-screenshot of.
2. GE2KAP then takes a screenshot of the GE image only, not of any chart.
3. GE2KAP creates a kml file, containing the just the satellite image with the needed data for overlaying.
4. KML overlay can then overlay the GE image over any chart (Raster or vector chart, any scale...etc) in OpenCPN.

The change to GE2KAP would do this.

I have made the changes and now I'm trying to get the KML Overlay Plugin working. I put in the kmloverlay-test_pi.dll in the opencpn/plugin directory and the libexpat.dll and the zlib1.dll in the opencpn root. It comes up but doesn't display Gilletarom's test kml file nor the one that I create with GE2KAP. Both work on Google earth OK.

Here is what I have:

[LeaseOnLife]

Originally Posted by phiggins

The change to GE2KAP would do this.

I have made the changes and now I'm trying to get the KML Overlay Plugin working. I put in the kmloverlay-test_pi.dll in the opencpn/plugin directory and the libexpat.dll and the zlib1.dll in the opencpn root. It comes up but doesn't display Gilletarom's test kml file nor the one that I create with GE2KAP. Both work on Google earth OK.

Paul

just some ideas:

• toggle opengl on off, any difference?
• try a simple kml, created with GE, like a waypoint, then a track or a route, do they show?
• what windows version? I only have XP...
• send me your test file if you want, I send a PM with my email address
• .... hopefully SethDart chimes in ..

Dirk