Incidentally I should mention that the Augmented Reality Dev Camp http://ardevcamp.org is coming up on Dec 5th at the Hacker Dojo in Mountain View. If there's anybody who you feel should be there please invite them - it is free.
@anselm On Wed, Sep 16, 2009 at 10:29 AM, David Colleen <[email protected]>wrote: > Hi Anselm > > I concur with much of what you say but would like to address a few of your > points. > > 1. You may not be aware of this but last year X3D added a Network Sensor > Node. This is a listener spec that allows for things such as multi-user > shared state and live data updates from external sensors. The Network > Sensor > is already implemented in many of the X3D viewers. > > 2. You make a comment that VRML and X3D "are very heavy bulky formats". I > don't see a basis for this comment. Most real-time 3D formats are highly > related and of similar file sizes. An X3D binary is about as small as you > can get short of a stripped down triangle list. > > 3. I quite agree with you about the importance of federation and shared > data > to make AR useful. Next week, the Web 3D Consortium will be announcing a > call for participation, at the Engage virtual worlds show in San Jose (Sept > 23-24), to complete a fully open specification for shared multi-user worlds > that can be used by AR applications. Much of this work is already complete > but topics such as shared communications and MU servers still need to be > resolved. Leveraging other important open efforts such as XMPP/OpenFire, > PostGISql, MySQL and Geoserver will be hot topics. Please get involved! > > Thank you > > David Colleen > Planet 9 > > I would not use GML or GIS based approaches. I would use GeoRSS for > simple features and X3D for rich features. > > To elaborate: > > It doesn't seem like the AR focus would be say on connectivity of > street segments or different geodetic systems or say raster analysis > of different layers of ground cover, or doing transformations on > rendering with different styles. It seems like those extra powers > while useful are not core to the deliverable. > > Rather In my mind I see AR as more focusing on painting a high quality > UX experience on top of the real world. Keeping that experience > registered and in sync with the real world as much as possible and > providing interactivity and dynamic behavior. > > In many ways I see AR as drawing more on video game development > conventions rather than on GIS conventions. If I was asked to build > an end-to-end AR system from scratch I'd feel like I could get the job > done faster, safer and in a more durable way if it was based on more > similar practices instead. > > The kinds of conventions that a 3d video game has - and that VRML and > X3D have tend to reflect a different set of concerns. They tend to > utilize scene graphs http://en.wikipedia.org/wiki/Scene_graph and tend > to include concepts like : > > [ grouping node to group things ] > > [ transform nodes expressing 4x4 homogeneous world coordinates ] > > [ model node expressing 3d polyhedra ] > > [ appearance node expressing model textures and the like ] > > [ instance node; specifying an instance of a model ] > > [ behavior node; specifying rules over time to apply to an > instance ] > > The big win would be that your artists, designers and modelers could > use tools that they were already comfortable with. As a developer you > could grab tools that largely would already process, compress and > render the data. > > The key benefit however would be highly dynamic rendering. GML systems > tend to reflect a kind of 'static' scenery. A scenery that doesn't > update very often. VRML conventions tend to reflect a need for dynamic > behavior more - the increased emphasis on transforms, multiple > instancing and the like. > > All these grammars are isomorphic, but they are tuned to their > landscapes. I feel that it's easier to use a representation that is > closer to the goal rather than stretching another representation. > > VRML and X3D have many flaws as well; they tend to focus more on > presentational aspects - although often in the real world form is a > side effect of underlying function - and are very heavy bulky formats. > However they're heir to the legacy of games development and in my > mind AR will in turn start to be about visualization of highly dynamic > behavior that is constantly changing rather than say just showing you > where subways are. > > When I mean "dynamic" I mean AR views will start to show say where > friends are moving to, and the dynamic and fickle constantly changing > sets of relationships between people and objects around them, the > density of information clouds, dynamic personal routing options based > on traffic flows, coupons and redemption awards that shift from moment > to moment, historical re-enactments of stories embedded in the > landscape that you are traveling over, fantasy situations overlaid > over top of the ennui of real life, dynamic rewriting of placards and > billboards to remove annoyances from field of vision, constantly > changing statistics over-top of people that you are talking to... it's > going to be a very cartoon world very soon. > > Pragmatically however what's going on in an AR world is no different > from what we were doing 15 years ago with heads up displays. The same > problems of registration ( and of the headache inducing nausea that > comes from failing to keep registration in sync ) , the need to > manufacture a separate display for each eye in order to provide the > illusion of depth, the need to efficiently cull sort and manage the > potentially visible set, the need to balance very limited > computational resources - this is all completely utterly routine. The > joystick input is a GPS not just a position in an abstract 3d virtual > space. The only new thing is the need for new algorithms to keep the > overlay registered against arbitrary real world views. And perhaps in > the larger scale of AR there will be a need to finally solve federated > data and behavior publishing problems such as were tackled by Second > Life. > > If AR proposes to be distributed - so that instead of seeing just > LAYAR data or somebody elses data - that there is a federated way to > aggregate and share layers and have a consolidated view across > datasets from many vendors - then I'd just suggest GeoRSS personally > for simple features and X3D for rich features. In fact this whole > burgeoning field may breathe new life in to X3D... ( otherwise we'll > have to invent some kind of rdf3d I suppose ) . > > It would be nice if GeoRSS supported a hint about the orientation and > velocity of an object ( although these can be determined by two > successive GeoRSS publication events of a given object over time ). > > _______________________________________________ > Geowanking mailing list > [email protected] > http://geowanking.org/mailman/listinfo/geowanking_geowanking.org > >
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