Re: [Flightgear-devel] Experimental new scenery format - help required

[James T. <zak...@ma...>]

> On 3 Jun 2016, at 11:58, Thorsten Renk <tho...@sc...> wrote:
> 
> Anyone wanting to join in?
> 
> I think there's plenty of potential here - and plenty of issues which need  
> to be understood before this can really take off.
> 

One thing I would urge here, is to create the meta-texture at runtime from the vector data - i.e use CGAL + GDAL to ‘paint’ the vector data into textures as they are needed. This means the resolution of the meta-texture tiles can be adaptive, which gives a trivia solution to handling roads and similar - draw them into the meta texture (or an additional one) adaptively based on distance from viewer, etc.

In an /ideal/ world, we use a similar texture to deform the elevation vertices, and get free cutting of roads, etc into the heightmap without needing to build it in, but that’s harder.

As you say, either loading or rendering this meta-texture at runtime is effectively the same situation as photo-scenery - ‘give me the grid aligned texture covering this tile/sub-tile’. Whether it’s a loader from disk or a helper thread which paints the meta-texture on demand is almost irrelevant.

The problem is the logic to do the loading / re-loading of such textures almost certainly exists in osgEarth already, but I haven’t been able to establish how separate the mechanism is, i.e if we can use that part on its own. Creating the logic from scratch needs some deep OSG plumbing that is … possible … but not fun.

But in general I am quite interested, yes.

Kind regards,
James