[vos-d] Online Space

[chris]

On 2/2/07, Reed Hedges <reed at interreality.org> wrote:
>
> Karsten and Chris are both right and have insightful comments.

thx Reed :)

>
> There's no real computational or memory restriction on the size of a
> volume of space *as a volume of space*  Chris is talking about the
> representation of coordinates.
>
> [[I.e. the only reason that a 1x1x1 kilometer space is different from a
> 1x1x1 meter space is that the 3 numbers are bigger. It's not like every
> 1x1x1 m cube within the 1x1x1 km space needs N bytes of RAM or anything :)]]
>
> In the past we've talked about the problems of resolution of large
> floating point numbers but never came to any solution for that per se,
> but perhaps to someday do automatic subdivision of the space into
> multiple sectors, whenever  a need for a tool like that comes up.  So
> you enter new subbordinate or "nested" coordinate systems as you move
> around.
>
subdivision of space is the most common approach but it does not give
a true continuous
world space to move around in and has a lot of overheads managing the
segments. There are also a multitude of special case problems that
occur at the boundaries: it can become
 a mess. Artificially managing this thru portals is ok for games but
does not suit all apps - like a virtual earth, for example.

> If you want to be able to see that whole galaxy in the rendering all at
> once that might be a bit of a challenge, but should be possible to
> figure out. (My guess is that graphics research has already discovered
> some solutions to this?)

The best combo of techniques from research IMHO is what I call
origin-centric techniques that build on the concept of a continuous
floating origin (in the client side display system), includes special
management of clip planes and LOD and a slightly different simulation
pipeline architecture end-to-end from server to client.  Plus stuff
like imposters for distant objects in galaxies.

Note since this is all the subject of my thesis I may be considered a
bit biased in this area :)

cheers,

chris