Re: [Flightgear-devel] Terrasync for WS3.0

[Stuart B. <stu...@gm...>]

Hi Torsten,

On Mon, Jan 8, 2024 at 4:27 PM Torsten Dreyer wrote:

> Speaking as someone who has collected/inherited bits and pieces of "hey,
> this looks easy"
> data and infrastructure ideas over the last decade or so:
>
> Terrasyncing ws3.0 is straightforward and our DNS resolver system is ready
> for it.
> So, "this looks easy". However, keep in mind that for making this
> "official", I strongly
> recommend thinking about some kind of process to
>
>    - create and allow updates of the scenery sometimes
>    - do this even if the original creator has left the project
>    - incorporate changes into existing scenery (doing this manually gets
>    boring over time)
>    - work in coexistance with existing processes, think of the scenery
>    database e.g.
>    - manage expectations from our users
>
> None of these should hold you back collecting and hosting the data in the
> way you mentioned.
> You can start right away with your server, add the .dirindex files and
> make people use your T/S
> mirror by setting the correct property on startup.
>
> But please think carefully about the above mentioned items (and maybe some
> more) before
> going large scale.
>

These are really good points.  However I think we have a big advantage in
WS3.0 over WS2.0 from
a manageability perspective because it uses a regular elevation mesh that
shouldn't change much over
time or across scenery, and the granularity of scenery is well defined as
1x1 degree blocks.

WS2.0 has an irregular mesh which means a new scenery block may not "fit"
in with surrounding tiles, and
new elevation of scenery objects has to be calcuated required.  My
expectation is that all WS3.0 scenery
will use the same NASADEM elevation model.  Because the mesh is regular and
does not vary with whatever
scenery raster a scenery designer has created, it should be possible to
replace any 1x1 block seamlessly
(both figuratively and literally - as the edges should line up exactly),
and without requiring any updates to
scenery object elevations.

I think this should address the major headaches in adding new scenery we
have had in the past, but I haven't
been at the coalface of doing this, so perhaps there are other traps for
the unwary?

-Stuart