Re: [www-vrml] X3D EXTERNPROTO [was: VRML still the most ...]

[Braden McDaniel <braden@endoframe.com>]

On Sat, 2004-09-04 at 09:56 -0700, Leonard Daly wrote:
> Paul,
> 
> A browser-specific node should be identified as belonging to that
> particular browser. So BTC calls their nodes BTC_. Xj3D is (already)
> using xj3d_. This tells content developers that this node is
> particular to that browser. No individual browser builder should call
> their node Joystick. That way you don't have "generic" node names that
> have browser-specific features. It helps ensure cross-browser
> compatibility.

With the EXTERNPROTO approach, content developers could call the nodes
*whatever they wanted*. The only thing that had to be unique was the URI
reference to the implementation. The possibility of a collision is
virtually nil, since there exist well-defined conventions for URI
naming.

> If there is sufficient support or interest in the community (meaning
> Web3D members), the X3D Specification WG will take up the matter of
> adding the new node to the base specification. The Specification WG
> will evaluate the request for a new node. Included in the evaluation
> will be breath of interest, compatibility with the specification, and
> IP issues. If the WG accepts the need for the new node, then it will
> be scheduled into a suitable amendment to the spec. In the example,
> the new node would be called Joystick.
> 
> There is nothing in this process that would break existing content.

Actually there is. If W3DC picks a name that users have employed as a
PROTO or EXTERNPROTO name, it will break content. And this is not an
unlikely scenario, as PROTOs/EXTERNPROTOs will inevitably be more
numerous than browser-specific nodes.

Now, I'm not saying that's inherently bad. Typically computer languages
run this risk in some form or other when they're extended with new
features. But I am pointing out that in this respect the X3D solution is
no better than the VRML97 solution.

-- 
Braden McDaniel                           e-mail: <braden@endoframe.com>
<http://endoframe.com>                    Jabber: <braden@jabber.org>

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