Whatever happened to the Multipurpose Cadaster?

Vector1 asks “Will digital city models become one über model or separate models for specific domains? “.

This discussion reminds me of the “multipurpose cadaster” concept that used to circulate years ago. I don’t hear it mentioned much any more. Also we used to hear about the importance of “topology” and how that is the key differentiator between CAD and GIS.

It seems that what is missing in urban models is the connectivity, e.g. how do you walk from room 1240 in bldg A to room 5320 in bldg B ? Topology is what connects these. It also seems like early implementations of topology made us accustomed to thinking of connectivity solely in terms of polylines (e.g. street centerlines).

Perhaps we need to think of a building as a network of rooms. Each room is a node in the network. Links between nodes can be built based on doorways, elevators, escalators, etc.. With topology defined in this way, first responders could be dispatched more effectively.

Just so happens the best graphic I could find illustrating this concept is from the Texas GIS Forum being held in Austin Oct 27-31. While I’m not sure if there will be any presentations on building connectivity per se, it should be a good conference.

Texas GIS Forum

Texas GIS Forum


6 comments so far

  1. Vector One on

    I’m not sure where the term ‘multi-purpose cadastre’ originates from, but it seems much like traditional GIS since many people attempt to build features of all types on a landscape with a continuous surface.

    You make a good point about networks. I would imagine that all members of a department in an organisation do not have their offices all lined up in a row. It would be interesting to understand workflows in terms of connections between spaces. Maybe ‘track’ data for a week or three and see where it goes?

  2. Kirk Kuykendall on

    There’s a lot of work involved in abstracting the essential data elements from a general purpose GIS to meet the requirements of a specific model. Water GIS layers get skeletonized. Electric distribution GIS layers are used to create circuit diagrams. Street centerline GIS layers are used to create network analysis (routing) layers … In each of these cases the problems arise in keeping the data used by the model in synch with the underlying GIS data from which it was generated. The work flow is definitely an issue. Usually there’s a centralized GIS department maintaining the base data, with different departments responsible for the models. Synchronization requires strong collaboration between departments. Add on top of that the time dimension (where models are based on projected conditions) and things get very complicated very quickly.

    It is difficult for an organization to impose these necessary work flows without dis-empowering (and losing) the more innovative workers.

  3. vectorone on


    Is it possible to take a schematic diagram and georeference it in 3D space?

    This could be very useful. I have no clue how it is done though.

  4. Kirk Kuykendall on

    Hi VectorOne –
    I don’t do a lot of 3D work, but I have played a bit with Sketchup and really like it. I think they might do something similar to this. When there is a city with a large existing collection of kmz files, I suspect there is some way I to digitize a new building into that space without intersecting existing ones. A 3D schematic would be useful for my house showing how all the light switches are connected. I have yet to figure that out, and I’ve lived here over 2 years now. I guess schematic isn’t quite right word for that though, what I really need is an as-built so I can drill a hole in a wall without worrying about hitting a pipe or wire. Not sure if Sketchup could do that though.

  5. Jorge Gil on

    Hi VectorOne,
    The network of the building and of urban areas as you decribe (the room or the space being the node) has been extensively studied in architecture within a theory called space syntax. There’s literature and case studies and more recently tools integrated in GIS to analyse those networks. However the building networks are only integrated in the urban network when studying large public buildings like museums or shopping malls. But one at a time for practical reasons: size and scale issues, complexity to model a 3D network.
    I can see that as the “next level”.

  6. Paul Tracey on


    There are a few extras that IMSI have produced of late that either help out specific TurboCAD users, such as furniture makers, or greatly improve other products with IMSI technology.

    One of these is the IDX Renditioner. It is a plug-in for Google SketchUp that provides high-quality photorealistic rendering – fast and easily. Renditioner works directly within SketchUp and lets you control the materials, advanced lighting components, environments, background images. Renditioner is “one button” easy with 3 render options of Preview, Standard and Presentation. It is simple enough for novices and yet powerful enough for professionals. Powerful features are optimized in a jargon free interface. Simplicity paired with speed and working directly in SketchUp, means you can achieve design visualization objectives more quickly. Renditioner offers 16 megapixel renderings for large-scale printing and powerful presentation of your designs.

    It is available for Windows XP or Vista on the PC, and OS/X 10.4 or 10.5 on the Mac and runs on either PowerPC or Intel-based Mac computers. As an extra it obviously requires you to already have SketchUp, but will be fine on the free version as well as the Pro version 6.4x or later. Like all photorealistic rendering, IDX Renditioner uses a system’s RAM and CPU power extensively, and is not recommended on systems with less than 1 GB RAM, with 2 GB recommended. Being fully multithreading, dual core, quad core, or dual quad core machines will each improve system performance dramatically.

    SketchUp is a nice piece of kit, but with the edition of Renditioner it jumps from good to professional, and then you import the SketchUp drawings into TurboCAD to add another dimension.

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