Applied Urban Modelling 2012

CASA researchers were out in force at the AUM 2012 meeting in Cambridge last week, organised by the urban modelling group at the Martin Centre. It was an enjoyable meeting, with a good range of participants from both academia and built-environment practitioners. I’ll discuss some highlights from my own GIS and visualisation perspective.

It was great to see Paul Waddell present UrbanSim, which is a well established and popular open source platform for land use transport modelling based on microsimulation. Current improvements include adding 3D visualisation capabilities and pedestrian accessibility. Paul also had a demo of an impressive new urban design tool using a procedural architecture approach similar to CityEngine. Colleagues at CASA Camilo Vargas and Melanie Bosredon are developing an UrbanSim model of London, so we will be returning to this software in future posts.

Andres Sevtsuk from City Form Lab MIT presented on modelling retail locations from a street network Space Syntax type approach. His team have developed an Urban Network Analysis tool for performing measures like Betweeness and Closeness within ArcGIS. This tool is also open source and it’s great to see so much interesting software going down this free to access route.

My favourite presentation was from past and present CASA researchers Kiril Stanilov and Paolo Mascucci. Kiril has painstakingly been putting together an incredibly detailed vector dataset of the growth of London’s road network from the 1700’s to the present day. The time-lapse sequence of the network growing looked spectacular, highlighting the path dependence from historical forms and the different sequences of growth in London’s history. There’s fantastic potential in this dataset for improving modelling and understanding of how cities grow and develop. A flavour of the data can be seen in the below poster image:

London 3D Augmented Reality Map

CASA hosted a very successful Smart Cities event last Friday, including presentations from Carlo Ratti, Mike Batty and Andy Hudson-Smith. The event premiered an interactive exhibition we have been working on, based on the theme of mixing physical and digital worlds. Some fantastic and fun exhibits have been developed by colleagues including George MacKerron, Steven GrayOllie O’Brien, Fabian Neuhaus, James Cheshire, Richard MiltonMartin de Jode, Ralph BarthelJon Reades, Hannah Fry, Toby DaviesPete Ferguson and Martin Austwick, who no doubt will be blogging about them all soon. Thanks to everyone who attended and contributed to a great day.

For my own exhibit I had a try at developing an augmented reality app to explore 3D urban data. The idea was to use iPads as the window into a 3D urban map of London, allowing the user to navigate around the virtual model to see different perspectives and focus on interesting parts of the data. Do we respond differently to data with a seemingly physical presence? Well this is one way to find out…

The app was developed in Unity using the Vuforia AR extension, and I was impressed with how accessible augmented reality technology has become using such tools. Firstly GIS data on urban form in London and air pollution was exported from ArcMap into Unity, and an interface to the data was developed. The core app without the AR capabilities can be viewed here (Unity web player required).

Next I followed the Vuforia iOS tutorials to add AR functionality. This approach uses a tracking image to position and scale the 3D model to the user’s viewpoint. Nice features of Vuforia include the ability to select your own tracking image, and that it can handle some occlusion of the image when the user moves to a particular part of the model, although a part of the tracking image must be in view of the camera at all times otherwise the model disappears from the user’s view. A large A0 poster was used as the tracking image, giving users greater flexibility in navigating the data.

The resulting app is very intuitive and delivered the desired ‘wow’ factor with many of the attendees at the conference. The AR aspect certainly encouraged users to explore the data, and identify patterns at different scales.

Adding more interactivity, animation and sorting out some issues with the target image (multiple smaller images would have worked better than one very large image) would all be nice for version 2. I’ll do a more detailed tutorial on the workflow developed later on if this is of interest.

Sketching the City in Motion

Whilst social scientists approach cities from rational and technical perspectives, it’s often interesting to get some inspiration from the creative arts world. Linking with artists is an emerging trend at CASA, with collaboration with Edinburgh College of Art through the TalesofThings project, the use of common visualisation tools such as Processing, and recent events like James’s presentation at the Mapping London Life event.

A shared challenge for artists and scientists is exploring the dynamics of cities, from the buzz of daily street life to the slower demolition and creation of the built-environment. An artist I admire for capturing these flows through static images is Lucinda Rogers, whose works have recently gone online on a new website. Her illustrations of street life in New York and London use line thickness and blurred colour to give the impression of forms in motion- from pedestrians and cars on the street to cranes dancing around St Pauls.

Rogers tends to choose Inner City subjects just at the edge of the centre, where gentrification processes are in tension with the historic fabric and traditional industries- locations such as Shoreditch and mid-town Manhattan. In this sense New York and London have much in common.

Another interesting London illustration book recently released in London Unfurled. Matteo Pericoli has done a series of books of super-long panoramas, published concertina style in one very long folded sheet. For London he follows the Thames from Hammersmith to Greenwich, with the north bank on one side of the page and the south bank on the other. This works well as the Thames is a key way  to ‘learn’ the form of London, from historic panoramas to the present day. If a 20 metre long panorama is too big for your coffee table, London Unfurled also comes in ipad version.

London Urban Form 3D Map

The structure of large cities such as London is complex and endlessly fascinating. Effective visualisation can reveal the many patterns in urban structures for research and planning tasks, and the visualisation challenge is to manage the multi-dimensional and dynamic nature of urban complexity. Here we explore the geography of land-use and density across Greater London using 3D cartography at a 500 metre grid scale (HD version here):

London is highly centralised, with recent patterns of intensification in the City of London, Canary Wharf and Inner London more generally cementing this pattern. Meanwhile much of Outer London struggles to attract higher value commercial uses. We will explore the agglomeration, property market, and planning policy processes that underlie these trends in future posts.

Many of land use patterns visible in London resemble the ‘classic’ urban location theory models: there is an extreme Alonso-type density gradient; retail uses retain a central-place hierarchy; and there are distinct radial corridors. Additionally further theories on the economics of mix-of-uses (e.g. Jacobs) and the lumpy mega-scale of real-estate investment are clearly key parts of London’s make-up.

The London Urban Form movie was created in ArcGlobe, which has some nice features like the ability to change the background mapping and animation timeline features. The advantages of doing the movie within GIS is the ability to easily combine spatial data at a variety of scales. Some of the more advanced animation effects that I would like to use such as geometry transitions (to show growth and decline) and controlling lighting are however not possible in GIS. A previous visualisation of this data in 3DS Max by Andy-Hudson Smith shows how these effects can be achieved.