Possible to use tile server as chart source?

[Tenedos]

I searched a bit but couldn't find an answer. Is there a way to use a tile server (e.g. https://tileservice.charts.noaa.gov/tiles/50000_1/{z}/{x}/{y}.png or https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}) in OpenCPN?

It is ok if they work only when there is Internet connectivity. I do a bunch of planning at dock where I have connectivity and being able to use some sources from a tile server would come very handy.

[rgleason]

These links do not work, so it is probably not possible.

[teppokurki]

The links as such are not usable in a browser, but describe a map source/server that can be used with the correct x, y and z parameters to load map tiles.

[phiggins]

SasPlanet can access ArcGIS Imagery and many other map sources. You can use Sat2Chart to create the charts in either Kap or Mbtiles. You can download Sat2Chart here: https://www.gdayii.ca/Downloads/Sat2Chart_Install.exe and it has liks to download all the other programs needed including SasPlanet.

[Tenedos]

Originally Posted by phiggins

SasPlanet can access ArcGIS Imagery and many other map sources. You can use Sat2Chart to create the charts in either Kap or Mbtiles. You can download Sat2Chart here: https://www.gdayii.ca/Downloads/Sat2Chart_Install.exe and it has liks to download all the other programs needed including SasPlanet.

Thanks, I saw that. It comes close but not quite the solution (and great utility btw, thanks for developing it!). Is there anything available as a source code we can use to build on?

[Tenedos]

Originally Posted by rgleason

These links do not work, so it is probably not possible.

As Teppo mentioned, these do require x, y and z populated to be a valid link. An actual working example would be something like this:

https://server.arcgisonline.com/ArcG.../15/11437/5246

[phiggins]

Sasplanet accesses those tiles servers using x,y,z so why would you want to create something else that does the same thing?

[HeywoodJ]

Originally Posted by phiggins

Sasplanet accesses those tiles servers using x,y,z so why would you want to create something else that does the same thing?

If I understand the question, OP doesn't want to do the same thing. Wants to be able to access the tiles directly from the internet into OpenCPN when internet service is available. Cuts out all the steps of creating "charts" for offline use, with the restriction that they can only be used when online.

I do see a use case for the idea, somewhat intrigued by it.

[phiggins]

Tenedos,
One user of Sat2Chart figured out how to add more maps to SasPlanet to access other tile servers. It is documented in the SasPlanet Help User Manual: "zmp format and map generation". This user is a member of the GE2KAP Facebook group. If you join the group and ask your question he may tell you how to do it.

[Tenedos]

Originally Posted by HeywoodJ

If I understand the question, OP doesn't want to do the same thing. Wants to be able to access the tiles directly from the internet into OpenCPN when internet service is available. Cuts out all the steps of creating "charts" for offline use, with the restriction that they can only be used when online.

Yes indeed.

Originally Posted by phiggins

One user of Sat2Chart figured out how to add more maps to SasPlanet to access other tile servers. It is documented in the SasPlanet Help User Manual: "zmp format and map generation". This user is a member of the GE2KAP Facebook group. If you join the group and ask your question he may tell you how to do it.

Thanks Paul. I wasn't aware of the group. Will try it there.

[Tenedos]

Ok, an update on this. I think I found a way to hack OpenCPN to support online tile servers by tweaking mbtiles loader. But after spending a few hours trying to compile OpenCPN on macOS, I gave up. Instructions for building on macOS seems outdated.

So, I took an easier path and wrote a simple python script to download tiles and convert them to an MBTiles file. OpenCPN happily processes those. See the screenshot. I also built a simple web interface to choose the areas to download in rectangles (see the second screenshot). I think Sat2Chart does something similar but I am a MacOS shop so Windows didn't really work out for me.

I put the source code here: https://github.com/itemir/rpi_boat_u...rts_to_mbtiles

I still want to go back and hack OpenCPN itself when I have some more time but learning curve was a bit steep, so that is for a later date.

If there any active OpenCPN developers who see this thread, I would appreciate some up-to-date instructions on compiling on macOS and maybe a plugin developers guide. Something similar to Signal K Server Plugins doc would go a long way and would be greatly appreciated.

[nohal]

Look at https://github.com/OpenCPN/OpenCPN/b...build-macos.sh

[Tenedos]

Originally Posted by nohal

Look at https://github.com/OpenCPN/OpenCPN/b...build-macos.sh

Thanks, this was much easier! Someone should update the build instructions on the web page.

If you also have any pointers for a starter plugin project, it will be great.

[nohal]

https://github.com/Rasbats/shipdriver_pi/

Feel free to be that someone, otherwise we will get to it as time allows, probably shortly after 5.8 is out.

[Tenedos]

Closure on this. I could indeed tweak mbtiles.cpp to load tiles dynamically from an online server but performance was poor. Panning was very slow and at times frozen until all tiles were downloaded. I think this needs to be built a bit more intelligently with async loading, maybe multi-threaded downloads and potentially caching. I won't be able to get that far though.

I mostly achieved what I needed with the script I linked above.

@nohal, thanks for the pointers, it was fun to play with OpenCPN's source code, helped me understand the code layout a bit better. Maybe I will come back to contribute something useful at a later time.