X3D Earth and the Geospatial Web - the development of a Web Viewpoint Service?
Today Web3D joined forces with the Open Geospatial Consortium (OGC) to further the development of something called the Geospatial Web, a movement already underway that embraces many values and goals that the Web3D community shares—open standards of course, but also open access to data, community, and the positive transformative power of the Web.
The vision and center of gravity of this “Geospatial Web” is well articulated in the OGC’s WMS and WFS specifications and the activities that have been spawned around them, such as Geoserver & deegree (reference open source WFS & WMS servers respectively), OpenLayers (a Web 2.0/AJAX API for displaying map data that works in standard browsers), and GeoRSS.
The WMS and WFS specifications define open standards service structures and formats for delivering map data (including constituent elements like layers and features) over the Internet. Web 2.0/AJAX is a perfect complement to WMS/WFS, and all of this is fundamentally more open than traditional closed map data re-purposed to the Web (insert your favorite GIS company, closed GIS data source, or proprietary 3D earth browser here).
But the WMS and WFS initiatives are principally targeted to 2D. What Web3D’s X3D Earth initiative can contribute might be something like a “Web Viewpoint Service” - the ability to query and deliver geospatial data from a perspective other than a 2D bounding box with a zoom function - i.e. the 3D Geospatial Web.
What would a “Web Viewpoint Service” return to the client side viewer? It could be X3D models, of course, but it needs to be more. It could, and perhaps should also be a more comprehensive solution that includes 3D with text overlays, audio, and video (e.g. augmented reality), 3D waypoints, real-time weather, real-world physics, cross-sectioning, even 3D PDFs—whatever the client requesting wants.
From this thinking comes a potential line of deliverables and activities that need to be considered in the setting up of the X3D Earth activity:
- a WMS/WFS extension server that understands and responds to viewpoint-oriented requests (a Web Viewpoint Service, if you will)
- an AJAX-based client API ala Open Layers that understands and returns viewpoint-oriented sessions (ie not just node extensions to X3D, though such an API might “wrap or feed an X3D browser in a DIV tag.”
Organization, deliverables, and calls-to-action also emerge from such a direction. For example, a client-side 3D-enabled earth that Web developers can install on any web page (no plugin required, but perhaps plugin-upgradeable). Such a direction also helps to align with natural categories of users of the Geospatial Web—from point-of-interest list builders who don’t want to understand GIS, much less 3D, to put a meaningful map on their web page, to the most hard-core specific guru-required use cases.
So the “client side” of X3D Earth could feed an X3D browser, but it shouldn’t have to. To achieve this, the rough equivalent of an X3D server (spatially aware) is needed, and once the server side of “Web3D” is addressed, will help to address a temptation to too-narrowly define, or constrain the definition, of a 3D Geospatial Web. Ironically, by not requiring X3D players as the “price of entry” to view 3D Geospatial Web, this may actually drive much wider X3D adoption.
The Web3D Consortium is aware of the industry events scheduled in 2007 for earth initiatives and potentially X3D Earth could premiere at the Where 2.0 conference next May in San Jose, http://conferences.oreillynet.com/where2007/. Other events, Web3D 2007, GIS, graphics, and governmental, are useful also but being part of the great world alongside the Geospatial web world will bring this work to a point of adoption a whole lot faster than the simple standardization route. Development and acceptance first, standardization later.
** Special thanks to Rob Glidden for his insightful feedback on this subject.