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3D has designs
on urban modelling

GEOFF ZEISS
Director, Autodesk Geospatial Technology
The world is facing serious challenges
including climate change, aging infrastructure,
shrinking workforce and lagging
productivity.
In industrialised countries, the challenge is crumbling infrastructure
and replacing unsustainable structures and the
impact of economic downturn. This needs to be checked by
speeding up and increasing infrastructure spending at various
levels of government. In emerging economies, development
of new and sustainable infrastructure poses the challenge.
NEW DESIGN TECHNOLOGIES
To address these challenges, architects, designers and engineers
are adopting new technologies. The business drivers
for these transformative technology advances are productivity
and efficiency in the entire lifecycle from design, build,
through operate and manage.
Most of the world’s buildings and infrastructure like roads
and highways, power, water and waste water, telecommunications
and oil and gas pipeline networks were traditionally
designed using CAD desktop applications. The objective of
this CAD approach to design is a paper drawing, but increasingly
architects and engineers are adopting a model-driven
approach to design that results in an intelligent representation
of a building, bridge or any other structure. In architectural
design, this is referred to as building information modelling
or BIM. Many people in the industry are convinced
that BIM not only reduces the cost of design and construction
for new structures, but can also significantly reduce the
downstream costs associated with operation and maintenance.
Another important trend in IT in the last five years is
geospatial enabling, which simply means making applications
location aware. For example, all the major search
engines like Google and Yahoo now incorporate location so
that searches almost always result in an option to view a
map using Google Earth, Google Maps or Yahoo Maps. All
major relational database management systems including
Oracle, MySQL and Microsoft SQL Server now support spatial
data types. Architectural and engineering design applications
are now able to support real world coordinate systems.
The important drivers for integrating geospatial with engineering
and architectural design are local government regulation,
for example, right to light, noise abatement and view
protection, sustainability objectives like maximising green
space, reducing impervious cover, eliminating heat islands,
maximising natural lighting and reducing energy use and
emissions.
Once the preserve of gamers, 3D simulation technology is
now an important tool used by architects and engineers to
experience a building or other structure during the design

phase itself. 3D simulation relies on many of the same 3D
visualisation and simulation technologies underlying computer
games and allows architects and engineers to convey
their designs more effectively, reduces the risk of major modifications
to built structures and enables optimisation of
buildings and infrastructure for their full life-cycle including
operations and maintenance.
The integration of these key technologies including model
driven design, geospatial enabling and 3D simulation provides
high quality visual environment and analytical framework
that enables seamless access to architectural and engineering
design, traditional GIS, new data sources such as
laser scanning and high resolution photogrammetry and
transportation, utility and telecommunications network
data inside, outside and under a facility.
"
An important trend in IT in the
last five years is geospatial enabling,
which simply means making
applications location aware. All the
major search engines like Google and
Yahoo now incorporate location so that
searches almost always result in an
option to view a map using Google
Earth, Google Maps or Yahoo Maps"
URBAN MODELLING
But these new technologies are not only changing how we
design, build, operate and manage buildings and infrastructure,
but are enabling the intelligent 3D precision simulation
of entire urban environments.
The data required for a seamless view of an urban environment
already exists in precision digital form, in the form of
CAD drawing files, BIM models, utility and telecommunication
network infrastructure databases, LIDAR and traditional
GIS data. Integrating precision engineering data to deliver a
precise synthetic environment that can be used to simulate
the inside (utilities, HVAC systems, furniture, elevators,
walls, doors, windows and structural details), outside (aerial
utilities, full city blocks of 3D detail, road access) and under
(underground water, wastewater, gas, power, and telecommunications
systems) of an urban environment creates an
intelligent model that can be used for visualisation, analysis
and simulation. For example, urban simulation can be used
to analyse the load impact of a new building on a utility network,
how the building will shade the surrounding area at
different times of the day and year, how much daylight will
be available in interior spaces at different times of the day
and of the year, how noise from a nearby sports stadium will
impact residents of the building and how the building will
affect traffic patterns.
A 3D simulation of an urban development before it is constructed
enables citizens to experience and understand how
the development will impact them in a much more intuitive

way than is now possible. Cities trying to attract new business
are finding that a 3D model is able to demonstrate in an
intuitive manner the advantages of a particular location in
terms of proximity to services such as transportation networks
and hubs, recreation and educational facilities. In the
past twenty years, many of the world’s largest cities like the
City of Vancouver and engineering firms like Parsons Brinckerhoff
have developed 3D models using applications like 3ds
Max. Developing these models required sophisticated modelling
techniques and skills that are not accessible to smaller
municipalities.
Technical advances are now making 3D urban modelling
available to a much broader market including medium to
small municipalities. New software applications for integrating
engineering design data, utility, transportation and
communications networks, traditional GIS data and data
captured using high resolution photogrammetry and laser
scanning are making it possible for a much broader range of
users to create and deploy 3D urban models to the desktop
and across the Web.
As an example, let’s walk through the process to create a
digital city from existing data, add visual effects to the digital
"
New software applications for integrating
design data, utility, transportation
and communications networks,
traditional GIS data and data captured
using high resolution photogrammetry
and laser scanning are making it
possible for a broader range of users to
create and deploy 3D urban models to
the desktop and across the Web"
model and use it to do analyses and create images and
animations using a desktop digital city modelling application
called LandXplorer.
The first step in creating a digital city is typically to begin
with a digital terrain model. Land Xplorer allows you to
import terrain models in a variety of formats, for example,
grid formats including Arc/Info Grid, Nasa SRTM, GeoTIFF,
Erdas Imagine and USGS DEM. To give the terrain a more
realistic look, raster images can be added as terrain textures
from aerial photography, satellite imagery and scanned
maps in a variety of formats including GeoTIFF, ECW, MrSid,
JPEG2000, and PNG. Terrain textures can be blended to provide
more information. Level of Detail 1 (LoD1) building models
can be created by extruding simple building footprints
prepared in AutoCAD, ArcGIS, Microstation or MapInfo using
building heights stored in an attribute table.
To make building blocks more realistic, individual buildings
can be accessed and the properties of each building edited,
for example, by choosing different generic roof types.
Existing 3d vector files can be imported to create LoD2 buildings
with discrete roof, wall and floor entities using data
from ESRI 2D and 3D Shape, GML and CityGML files. LoD3
georeferenced buildings can be imported from 3ds Max, X3D,
and Collada which contain realistic details and building
facades generated from digital photographs.
Non-georeferenced 3D models of bridges and other structures
can be added and positioned on the surface by dragging
and dropping. Point data such as the location of
busstops or vegetation can be imported and symbolised
using images or 3D models.
The second step is to make the digital model more visually
compelling adding generic building facades to the building
blocks. The textures of individual buildings can be edited, for
example, to change the depth of the texture to better fit the

building. Terrain texture can be draped on the roofs of buildings.
Dynamic skies including cloud movement, cloud density,
sun elevation and light intensity can be added and adjusted
to simulate different lighting conditions.
Water shading information can be added from CityGML
files to give the impression of a dynamic body of water
including reflections of structures and clouds in water bodies.
The digital model can be packaged and made available for
visualisation as well as analysis and simulation. Information
generated during the planning process can be imported from
existing data sources, for example, a planned development
footprint. Rules-based actions can be used to thematically
analyse the building models, for example, to find and colour
all the residential buildings in the project area.
Utility infrastructure data can be imported, scanned development
plans can be dropped onto the terrain for better
understanding of the planned simulation and proposed
building models can be added by extruding building footprints
from engineering or architectural drawings. Distances
to neighbouring structures can be measured to help understand
the impact development would have on the surrounding
"
Director, Autodesk Geospatial Technology
35 MARCH 200 9 GIS DEVELOPMENT
Static digital images and video
animations can be created for
presentations using a variety of
techniques including trackball, free
flight, typical paedestrian navigation,
3D-panning, directed flight using visual
bookmarks and camera paths"

environment. Finally, static digital images and video animations
can be created for presentations using a variety of
techniques including trackball, free flight, typical paedestrian
navigation, 3D-panning, directed flight using visual bookmarks
and camera paths. More images of 3D digital cities created
using these techniques can be found at
http://www.landxplorer. com/ showroom.aspx.
In summary, 3D modelling is no longer just for ‘big cities’.
Technical advances have made this technology available to a
much broader market including small to medium-sized
municipalities who may have felt that in the past that 3D
urban modelling was out of their reach.