The Spatial Miscellany

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A weblog. A website. A geospatial miscellany…

A next generation web mapping API…

So ArcGIS 10 has been out for a month, and it’s all very quite? A recent project threw up the opportunity to get down to work with the new JavaScript ‘2.0’ API and ArcGIS Server 10 – I’m really impressed, and it really distinguishes the ESRI web mapping kit, from the ever popular GYM & OpenLayers.

Most impressive is the level of abstraction in the API, ESRI are really delivering on the sales pitch on this one, its small and powerful – this makes it super quick to develop with, case in hand being the handful of lines required to build a custom identify dialog. In three days last week we went from a handful of Feature Classes to a full-blown web app (and it’s robust). But it’s not just the lean API that makes for rapid development, the close coupling of ArcGIS Server to the Map Document also starts to pay dividends. I’ve always been cautious of MXD driven web services, as its eating up the full set of ArcObjects under the cover, which eats memory on the server, SOC processes rarely start the day on less than 60MBs for breakfast, but the trade off is access to all the goodness of the MXD, in this case some VBScript labelling and scale thresholds – this would be a nightmare and time consuming to code on the client.

Hungry Soc Monsters from Mandy Jouan - helping to make nice web maps =)
Hungry Soc Monsters from Mandy Jouan – helping to make nice web maps =)

From a consultancy perspective, how do you make a business model of delivering JS, Silverlight or Flex based solutions, when the pre-sales associated with securing the work could often be larger than the job itself?

ESRI Developer Summit 2008

It’s that time of year again, the Developer Summit and a trip to Palm Springs are just around the corner. The Q&A has just been posted on esri.com, here is one interesting question…”Will there be a replacement for MapObjects?

Palm Springs

For anyone not able to make it out to California, lots of sessions from the Dev Summit last year are available online as videos on the EDN website.

What happens when Second Life meets Google Earth?

That is the question asked in the July\August edition of MIT technology review. In a series of articles, the magazine suggests that a world of virtual earths and mirror globes will eventually replace the internet – a MetaVerse. This idea seems to be flavour of the month with similar articles appearing in other magazines (e.g. business week) and numerous blogs (including the prolific DigitalUrban) throughout the last couple of months.

Technology Review contributor, Wade Roush, talked with Google Maps director John Hanke about the feasibility of the MetaVerse. They suggest a logical first step towards the ‘MetaVerse’ is the representation of real geography, typical of mirror worlds like Google Earth (and ArcGIS Explorer), in virtual worlds like Second Life. Increasingly examples of this can apparently be found in Second Life, for example, researchers at the University of Denver host a dynamic NOAA weather map on a Second Life island. Roush and Hanke suggest the second and marginally more challenging step will be the representation of second life and its avatars in mirror worlds like ArcGIS Explorer and Google Earth. Well with the new OpenGL custom drawing capabilities in ArcGIS Explorer, that’s now possible. The wind vectors in the following video clip are rendered in OpenGL…

Why would you want to render second life avatars in ArcGIS Explorer? I really don’t know. But you can, and what’s more, you can now render any other OpenGL in ArcGIS Explorer. More usefully it may be the output of specialised software unique to your industry that you use to model, wind farms, air pollution, wind vectors or telecom coverage.

Pondering the potential of this new functionality, I discovered OGLE from eyebeam research. OGLE intercepts the OpenGL calls any application makes to the OpenGL library, using this technology it should be possible to extract anything that is drawn in OpenGL – as OpenGL, for example, the building layers in Google Earth, or even the avatars in Second Life. Using the new events and methods exposed in the new ArcGIS Explorer API, such data could now be rendered in ArcGIS Explorer (copyright permitting?).

James, Kirk and Keith remark on the latest release of ArcGIS Explorer elsewhere; and more info on the latest ArcGIS Explorer release can be found on the team blog and at the resource centre.

Do you drive Stick Shift?

I help to design software, it’s my day job. A smile crept across my face when a friend sent me a link to the following video:

Obviously, it’s a great plug for his book, but David Platt makes a good point in the video clip and something we continue to remain aware of here at ESRI. On this front I think ESRI make a fair effort, and a lot of time and energy is invested to ensure it’s the ‘end user’ experience that drives software development. For example, all our core software engineers are loosely coupled to product engineers (or product specialists), and it’s the product engineers that drive software development from an ‘end user’ perspective – at least that’s the theory; sometimes we get it right, sometimes there is room for improvement.

After watching the clip I surfed to Dave’s website whysoftwaresucks.com, where he has posted a sample chapter, I think he makes a valid remark when he states:

“The designers of the earliest computer programs didn’t care about making their products easy to use. Solving the computing problem at hand, for example, dealing with a printer to make the words come out properly on paper, was so difficult that no one had time or money left over for making a user’s life easier. A computer’s thinking time was enormously expensive, much more so than the user’s time. Forcing the human user to memorize complicated commands, instead of using computer power to provide a menu listing them, made economic sense. The relative costs are now reversed, of course, but almost everyone in the industry older than about 30 grew up in that type of environment. It can’t help but shape our thinking today, no matter how hard we try to leave it behind. Think of your older relatives who grew up in the Great Depression of the 1930’s, who even today can’t bear to throw away a sock with only one hole in it.”


Do GIS developers drive shift sticks?

Mashups with AGX



Keith Fraley @ the Location Based Soup has written his first, in a series of 12, custom tasks for ArcGIS Explorer (AGX). When you download ArcGIS Explorer, you also have the option to download and install an ArcGIS Explorer software developer kit (SDK). The SDK allows developers to use the ArcGIS Explorer API to build their own custom tasks. This functionality means you’re not limited to just the default tasks that come out of the box with AGX, for example, you could build your own custom version of the ‘create notes’ task, or something far more exciting that makes the most of your data.


Consuming a Mash-Up- circa 1950
British Gent consuming a mash-up, circa 1950.

Keith has worked from the USGS GeoRSS sample task in the SDK to build his own task that queries a web service and geo-locates items listed on the auction website eBay. The USGS GeoRSS sample task Keith used from the SDK makes a web request to the USGS for a GeoRSS file which details recent earthquakes. Using a combination of the .NET framework classes, XPath, and the AGX API, the GeoRSS file is parsed by the task, pertinent information regarding each earthquake is extracted, and represented in AGX as a PlaceResult.

The ArcGIS Explorer SDK is available for free as part of ArcGIS Server 9.2, and you can build custom tasks for AGX with Microsoft Visual Studio – the free edition is pretty useful.

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