Home' Position : Position Aug Spt 2015 Contents scans by constructing 'skates' (pictured),
on which the tripod would stand. This
allowed field crews to easily reposition
the tripod by simply rolling it to the
new location, locking the wheels and
resuming the scanning.
The work was also restrained by the
logistics of conducting survey work in a
fully functioning shopping centre. The
six or so staff directly involved with the
field work performed scanning day and
night, as some tenancies would only
allow daytime scanning. Other areas,
such as common areas and car parks,
were simply too populated to survey
accurately and safely.
The scans were also supplemented
by disto measurements and measuring
tape readings in the inaccessible confined
spaces, such as jam-packed backrooms
of shops. Using these methods, the field
crews were averaging no less than 60-70
scans a night being sent back into the
office for modelling.
Handling all that data
The sheer scale added complexity to what
was otherwise familiar survey work. "It's
work that we do on every job that we
undertake," said Mr Milligan. "It comes
back to the size of it."
The final file database for the project
amounted to about 750 gigabytes.
Managing that data provided yet another
challenge, but as an established survey
firm, Project Surveyors had a plan from
the start: "We'd break it up so that we
were separating the centre into floors, and
the car park into different colours and
levels," said Mr Milligan.
"We had to break up the data, because
when we try to take that data into Revit
or AutoCAD, they can't handle massive
databases - so we would separate trading
floors into levels 1, 2, 3, and then break
those up into two or three different
sections, depending on how large the
Even then, managing the survey of
such a large and intricate building proved
to be a challenge that Project Surveyors
had to constantly wrangle, with some
sections such as fire stairs being missed
and forgotten due to something like a
temporarily locked door.
"I think you're always going to have
issues like that," said Mr Milligan. "But if
you've got a good workflow in place and a
good plan, you minimise that."
Simultaneously, the team back at the
Project Surveyors office was busy turning
all of that raw point cloud data into an
organised 3D model.
To assist them with the gargantuan
task, Project Surveyors hired BIM spatial
manager Andy Jackson, who was brought
in from England to join the team for
his experience in building information
modelling projects in the UK. It was
Jackson's role to handle all the incoming
data and oversee the 3D modelling of it
all. Leica's Cyclone 9.0 software was used
to clean and register the point clouds and
also publish 3D images for use in Leica's
TruView panoramic point cloud viewer.
Revit 2014 was used to model architecture
elements, while the features of Revit MEP
was used to create pipes, plant, ducts,
and other services to create a partial MEP
Much of the modelling work was
outsourced overseas, however, and
while Project Surveyors has had success
outsourcing smaller, simpler projects,
they would opt to perform the modelling
in-house in future projects of this nature.
"It's hard to make sure everyone's
modelling to the same standards, so you'd
find different people having different
interpretations," said Mr Milligan.
"Ideally, we'd like to do a lot more of
it with fewer people so that we can
control the integrity of it and how it's all
presented. We also want to make sure
we've got certain standards across the
board, and if you've got fewer people
working on it, you've got better control."
Mr Milligan attributed much of the
success of the project to Leica's recently
updated Cyclone software for point
cloud data. "It allowed us to register
it and process the point cloud data a
lot quicker than we previously would
have done it, so that was a significant
development and something that I think
made a massive improvement."
Aerial photo showing
the extent of the
survey at Castle Towers
3D model with overlaid point cloud.
Links Archive Position Jun Jul 2015 Position Oct Nov 2015 Navigation Previous Page Next Page