Re: [vos-d] A3dl redesign (was Re: Scaling and Origins -- 0.23 vs 0.24)

2007-05-24 Thread reed

___
vos-d mailing list
vos-d@interreality.org
http://www.interreality.org/cgi-bin/mailman/listinfo/vos-d


Re: [vos-d] A3dl redesign (was Re: Scaling and Origins -- 0.23 vs 0.24)

2007-05-22 Thread Reed Hedges

In making A3DL we did take some inspiration from VRML.  However, VRML
(and X3D) have some aspects that if adopted directly would make A3DL
a bit less efficient or more cumbersome.  We have all the structure that
comes from VOS to use.  X3D does some stuff just because VRML did it,
and VRML97 does it because VRML 1.0 did it, and VRML 1.0 did it because
Inventor did it, and SGI GL,  etc. etc.  

We should do what is closest to overall common practice. i.e. if VRML,
CrystalSpace, other 3D engines, Collada, etc. all do somtehing in a very
similar way, we should probably do that.   In some cases we will have to
break with X3D (or other existing stuff) though and do it better (better
for VOS).

The two overarching design goals for A3DL are to first, make it work
efficiently and be flexible and useful to manipulate A3DL objects in and
of itself.   Second, to make it easy to import existing content.  These
two things will be in conflict sometimes.  I don't know which should be
primary, but I lean towards making A3DL itself easy to use (e.g. imagine
you're interactively editing A3DL objects with a GUI version of mesh)
and very flexible (e.g. imagine that you want to share content between a
3D and a 2D application, or between 3D worlds, you want to make something 
clever and neat in A3DL.)

(Also, in the "designing metaobject structures" vein, there's a Wiki
page about "Tips and Best Practices" here:
http://interreality.org/wiki/TipsAndBestPractices . I started it out
with a few tips and TODO items, add more TODOs (and tips) as you
encounter situations and figure things out.)



Reed

___
vos-d mailing list
vos-d@interreality.org
http://www.interreality.org/cgi-bin/mailman/listinfo/vos-d


Re: [vos-d] A3dl redesign (was Re: Scaling and Origins -- 0.23 vs 0.24)

2007-05-21 Thread chris

All good points IMHO, it would make it easier to import/export/translate
between formats,

chris

On 22/05/07, Ken Taylor <[EMAIL PROTECTED]> wrote:


Peter Amstutz wrote:
> Since most of the work has gone into the network layer, a lot of stuff
> in the 3D layer was a quick proof of concept rather than being really
> well thought out.  Even if s4 -> s5 transition wasn't necessary, an A3DL
> redesign was already on the plan.

There's a lot of unwritten stuff like this for a newbie to the VOS project
like me :)  But it's good to know. I didn't really know how set you guys
were on the current state of a3dl, but how much it seemed like "make it
work
easily in CS" was the main design objective made me a bit uncomfortable
with
it. But knowing that it was mostly a proof of concept and that a redesign
is
on the plan makes me feel a bit better.

So, I don't know if it's too early to start talking about redesigning
a3dl,
but thinking about it today I had a thought. You guys already want to have
VRML (and eventually X3D) translation to and from VOS/Interreality 3d
data.
Well, why not make it easier by desigining a3dl to be as close to 1:1 with
X3D as possible? The X3D guys are putting a lot of work into hashing out
the
things that an interoperable 3d standard needs, so why re-invent the
various
wheels? I'm not talking about adopting X3D file formats as the interchange
format of course, but rather having the object types and properties have a
1:1 correspondance with those in an X3D scenegraph, and have the formats
for
textures and meshes and shaders and such be X3D compatible.

Of course, it doesn't have to implement *all* of X3D, and will have its
own
extensions on top of what X3D specifies (I'm thinking something like
inter-server portals would probably be very vos-specific). But it might be
a
good idea to ride on top of their basic design. Also, doesn't X3D specify
different optional modules and levels of compliance? You could have that
kind of information published by servers and clients, even, to help with
service discovery. But I actually don't know too much about X3D at the
moment -- learning it is on my ever-expanding todo list :)

There will probably be some extra work in making crystal space loaders for
a3dl if it's done this way, but it's probably better for the VOS standard
in
the long run.

Of course, if there's some reason you guys don't want to do an
X3D-inspired
design and think it'd be better to start from scratch with the 3d scene
data
I would be really interested in your opinions. Does X3D have any serious
flaws that would hold it back from being the "right" data model for
Interreality 3D?

-Ken


___
vos-d mailing list
vos-d@interreality.org
http://www.interreality.org/cgi-bin/mailman/listinfo/vos-d





--
http://ping.com.au
http://systemic.com.au
http://planet-earth.org/Rez/RezIndex.html
--
It be a great secret: there be more truth at the centre.
___
vos-d mailing list
vos-d@interreality.org
http://www.interreality.org/cgi-bin/mailman/listinfo/vos-d