Re: [ogpx] URI schema for virtual world locations?

[Carlo Wood <[e-mail]>]

I pressed the 'send' button too soon, but almost immediately followed
up with a reply to myself (where I more or less took back the first
part, that you comment on ;).

My point was, there is only a need for a 3 dimensional cartesian coordinate
system really, relative to a region.

In order to be able to show map, it should be possible map regions
to some 2 dimensional coordinate system.

By using a global 3 dimensional *cartesian* coordinate system,
and do the latter mapping by projecting along the z-axis, we'd
force every world to be flat.

If that is what we decide for, so be it. But if we want to avoid
getting only flat worlds for some reason then we have two options:

* Either add support for other coordinate systems (cylindrical, polar...)

or 

* Let go of the "simple" way that local 3D coordinates are mapped
  to the 2D 'map' coordinates.

If on top of that we want to accommodate the fact that some regions
are not connected at all (you can't fly or walk from one to the
other: they do not have any intuitional or logical relative position),
we need to add the notions of 'spaces' (mathematical word), or
maybe call it 'map' as that is what it will boil down to: separate
maps of connected regions (I recall having posted a proposed word
for that for communication purposes: continents).

Hence my proposal for points 1.3 and 1.4:

1.3. there may be two forms of location representation:
map position (longitude/latitude) that give regions in a
given space, a place on a map, and cartesian coordinates
relative to the origin of a region (x,y,z).

1.4. the statement above (1.3) implies there is a public service
available to map between the {space, longitude, latitude}
"map coordinates" and points relative to a given region:

{space/map, longitude, latitude} <---> {region name, x, y}


I have no objection, not too strong anyway ;), against
continents being flat on the map, only allowing curved
land through special browsers. The reason for that is
that I think that otherwise it's just too hard to create
and show a map, something not worth the effort at this
point, not even during the design of this standard :/

Note that by setting "space/map" to a constant, this
extended proposal is completely consistent with how
SL currently works (one big map, and {longitude, latitude}
being the global coordinates). Yet, it would discourage
using {x, y, z} for global coordinates, but shows that
it's needed / better to use {region, x, y, z} for
locations, or alternatively {space/map, longitude, latitude, z}.

-- 
Carlo Wood <[e-mail]>