WW for Java and Microsoft Visual Earth

[fabrizio.giudici]

Hello.

I understand (and see screnshots :) ) that there's a VE plugin for the .NET version of WW. Is there any plan to port it under Java too or are there licensing issues?

[bull]

So far Microsoft have been happy for us to use VE imagery, so I don't see any licensing issues, it's more a matter of devs not doing it yet.

[fabrizio.giudici]

Where should I start? :-) Seriously, I don't know if I'm able to, but I can try. I already know about the tiling format of VE, I just need a starting point for plugging into the WW code.

[patmurris]

I fear there will be projections issues in WWJ since the only way to 'present' image tiles to the tile renderer is in lat/lon projection for now.

BTW: if you have notes aboute the VE tilling scheme, i'd be happy to have a copy ;)

[withak]

http://www.brains-n-brawn.com/default.aspx?vDir=veworldwind

Everything you might want to know about VE tiles. :) The .NET plugin reprojects the VE tile corners to lat/lon, there is no reason you couldn't do the same in java.

[patmurris]

The .NET plugin reprojects the VE tile corners to lat/lon, there is no reason you couldn't do the same in java.
Thanks for the link Withak.

The problem is the corners do not end up 'aligned' with the lat/lon grid - that is why they cannot fit in the quadtile scheme of the core, they are oblique somehow. At least that is what i understand of it.

To be used by the current WWJ tile renderer, the tiles would need to be reprojected by the retrieval service (at the pixel level) onto lat/lon aligned tiles, with a transparent area around. Think of an image you have rotated just a few degrees, you have triangular sections in each corners where the 'background' shows through.

That would be doable indeed. But it would certainly slow down the download of new tiles. Once they are in the cache however, it should work like another layer.

[what_nick]

Hi Pat,

As was suggested in another thread, the warp(rotation) can be performed in a pixel shader, i.e. in the GPU instead of the CPU, or texture coordinates changed.

Cheers,

Tisham.

[withak]

The other alternative would be to persuade MS to let Nowak scrape their entire tile server and make a real QTS out of the layers. ;)

[patmurris]

I have to point out that even with the post processing of tiles to reproject them onto a lat/lon grid, the tiles encompassing sectors would inevitably overlap - and would require a special handling, more involved than the actual TiledImageLayer.

It would be much easier to just ask WWJ to paint those tiles in such or such projection without worrying about the lat/lon grid, but that would need a rework of the current tile renderer to use variable texture coordinates or appropriate shaders... The idea is in the air though.