The truth is, scanning may be the only cost-effective solution to collect the existing world.
You simply can't get into a cathedral, petroleum refinery, or metropolitan multi-use entertainment facility and measure with rulers and be prepared to get the accuracy you should confidently design renovations.
Laser scanning may be the only way to take action.
Until recently, BIM users would have a group of "asbuilt drawings" put them right into a 3D modeling program and create a computer model to work from. Now, after several years of doing that, the harsh realization has surfaced there are many discrepancies between the "record drawings" and the actual environment to be constructed.
Whether it's sheetrock and wood, it might be adjusted to match. But whether it's glass, steel, concrete or mechanical equipment, a seemingly small error can grow too costly as it is much harder to warp and bend. (Putting expensive new equipment into an area that is too small is really a nightmare for the installer, designer, engineer and the insurance provider.)
These new 3D laser scanning technologies have dramatically changed the surveying industry - and they have changed it fast. But to really understand the evolution, let's have a step back....
2004: 360-Degree Scans
The first 360-degree scanners came onto the scene around 2004. Before that, if you wished to scan something above your head, you'd to tilt the scanner back and scan at a steep angle, because so many only had a 120-degree scan ability on the vertical axis. Several companies arrived with full straight scanners about this time that made it much easier.
2006: Time-of-Flight Scans
The next evolution was time-of flight scanners. In 2006, a time-of-flight scanner took about 45 minutes to one hour for a whole 360-degree scan. In the event that you could do 8-10 scans each day, you were doing very well. Today, the same can be carried out in about 12-15 minutes, with respect to the density you want a scan.
At our firm, our first scanning projects were roads. In a very complicated area, we'd scan 1"X 1". The time-of-fight scanners in the past could collect 4,000 points per second. Now they are able to easily collect 50,000 points per second!
2008: Phased-Based Scans
Today's phase-based scanners collect 2,000,000 points per second and can create a �-inch x �-inch pattern far away around 100 feet. That is incredible and as fast and dense as the average user needs. The hardware will eventually progress, faster and cheaper, but phase-based scanning is effective, stable, and provides the opportunity to scan just about anything in an acceptable about of time.
Present: Scan to BIM
Today, the big research money is going towards Scan to BIM technology, which converts vast amounts of points in the idea cloud into useful data.
Several companies have begun addressing this including small independent companies like Pointools, which developed a means for scanners to identify flat surfaces. (As small as this may seem, this is a huge advancement.) The program may also recognize pipes and model them automatically about 50% of the time. (Another major advancement.)
Now lots of the pipe programs are getting to exactly the same place and advancing the ball. Currently, we have been at what I call the "Model T Ford" in software packages, but every year the programs progress.
The next evolution
Having now scanned may highly complex areas in industrial sites, we have had to be able to compare them to the asbuilt drawings. In the horizontal view, they are generally close geometrically to the specific. However in their vertical axis, the pipes and duct work in the asbuilt drawings are rarely correct.
There are many reasons for this, but most often it is because the procedure is so difficult that whenever an installer sees an easier path, he generally takes it.
"Record drawings," or asbuilt surveys, are rarely done following the work is complete. Typically, BIM Surveys Leicestershire goes something like this: "Here are the design drawings. Redline any changes that you made."
There is not plenty of motivation to do a completely new survey. But if a design team takes these documents and models them to their computer programs, they are unknowingly creating multiple problems for the contractor on the brand new job.
We recently took a set of asbuilt documents for a complex project, modeled them and then compared them to the point cloud to accomplish a clash detection to find out potential interferences. The outcome was eye opening.
Several pipes, ducts, waterlines or fire lines in the ceiling were in the area shown on the record drawings. If these documents have been used, the MEP contractors would have spent ten times our fee "field fitting" the new utilities inside the old.
With the utility and cost of laser scanning, it might be smart to use one on every renovation project. If for nothing else, insurance! Just one field fit can sometimes cost far more compared to the scan itself.
If you scan the surroundings and put the proposed design into the point cloud, you can tell in just a few momemts where in fact the major interferences will be. We have found conflicts that could have taken up to $100,000 to fix if they had to be field-changed during construction. Some were fatal flaws in the required design clearance that could not have been achieved and a completely new design could have had to been submitted.
Scanning to BIM is really a big and extremely important part of surveying. Right now, it is the design software that's trying to meet up with the scanning potential. Already this season, several new programs have come out that are far better at accepting point clouds and computer models, but they still have quite a distance to go.
Devoid of a design based on a laser scan of the specific environment is a risk that few designers should take. I know I wouldn't want to tell an owner that there is a construction problem that could have already been avoided with a cheap laser scan.
Laser scanning has evolved from a "luxury" to a best practice and it's really not just a step that any prudent designer should skip.