[X3D-Public] X3dom + PROTO
Alan Hudson
giles at yumetech.com
Tue Nov 10 08:25:55 PST 2009
Johannes Behr wrote:
> Hi,
>
>>
>> First of all, congratulations for the great work you and your team is
>> doing with x3dom. In my opinion, this could be the key for the X3D's
>> future, specially because a plug-in will not be necesary for users.
>>
>> I have a question about one think you said in a previus e-mail:
>> " X3D reduced to the max: No PROTO or Scripting on the X3D-scene-side.
>> All partitioning and scripting is done on the HTML side."
>>
>> What does it mean? Does it mean it will not be possible to use X3D
>> "files" using PROTO in X3dom? Will exist and alternative way for doing
>> the same (or similar) including passing parameters values to "proto
>> instances"?
>
> We propose a new experimental "HTML" profile extending the "Interchange
> profile"
> As in Interchange (Core Level 1, Scripting Level 0) Protos and
> scripting are "Optional"
>
> http://www.x3dom.org/?page_id=158
>
> We discussed this issue in the group and choice to keep Scripting and
> Protos out for the following reasons:
>
> 1) Protos and (multi-language) Scripting are feature which make good,
> conforming and performing implementation really hard.
> 2) There is already a Script-Engine for free on the browser side
> 3) With this lower set on feature different backends and native-impl.
> should be easier compatible
> 4) Protos are an usual mix of sub-typing and aggregation which is very
> unusual for HTML-content people.
> 5) On some closed mobile platforms is it not allowed to introduce new
> scripting engines.
>
I would agree with this as a good starting place. Take the smallest
subset of X3D needed for the domain. Sell the whole spec as a concept
but start small.
> We still don't have a good substitute for PROTOS yet but already have
> some ideas.
import/export on inlines is somewhat a replacement for PROTO's. It does
give an interface to the file.
> Scripting is JavaScript in the HTML document
>
> We sill support DEF/USE (and id/USE), Inlines and Routes as X3D concepts.
> (We do not know any HTML concepts which could be utilized instead)
>
> USE references and Inlines are essential for larger and more complex
> data and Routes are needed for per-frame updates in the retained model.
> We think we should support those and therefore support Interpolator and
> Follower. It's not crucial for the webgl/js implementation since we have
> to do all updates in javascript anyways but it is a performance plus for
> native/plugin backends.
>
> The "HTML"-profile is the "minimal" supported profile in X3DOM.
> Different Backbends (e.g. WebGL, O3D, SAI-Plugin, browser-native ...
> will support various profiles ).
> We can even see that the content profile requests or requires a specific
> level or kind of implementation.
> However, the content author should _never_ choice a specific backend but
> only request a specific profile.
>
> But remember always: We do not try to solve all X3D problems with this
> proposal and working-group.
> We try hard to ease the integration of X3D and HTML and close the gap.
>
> This will not be the optimal platform for all 3D or even X3D
> application. There will be always good reasons
> (e.g. Augmented Reality) for fat-clients and dedicated X3D-Systems (e.g.
> InstantReality, FreeWRL, ...).
>
> We try to build a good ground for Web-Applications which need some form
> of easy access to 3D for
> there 3D-UI, Visual-Analytics- or shop-application.
>
> regards
> johannes
>
>
--
Alan Hudson
President Yumetech, Inc. www.yumetech.com
President Web3D Consortium www.web3d.org
206 340 8900 ext 111
Open Source CAN be free, as in "free puppy"
More information about the X3D-Public
mailing list