4 Applications for Laser Scanning
Laser scanning is an evolving technology on the construction jobsite because of constant advances in both the hardware and software. Once only the realm of retrofits and renovations, laser scanning has become a de facto quality check on new construction, as well. Four applications for laser scanning include 2D construction drawings, 3D models, measuring floors for flatness and walls for verticality, and comparing the design to the as-built.
How does your firm use laser scanning today and how will you apply it tomorrow? Count on the team from Trimble Buildings and our dedicated network of dealers to continually push the envelope and develop new best practices for your team.
Create 2D Construction Drawings from 3D Point Clouds Using Trimble RealWorks
Oftentimes on adaptive re-use projects, retrofits, and renovations, there is incomplete, inaccurate, or even non-existent construction documentation. Laser scanning affords us the opportunity to correct that.
With laser scanning, we have the option to slice the point cloud in order to create construction drawings, or even trace over the point could to create a 3D model. Our customers use Trimble RealWorks (most often used in conjunction with the TX5 laser scanner) to manipulate the point cloud. RealWorks is Trimble's 3D point cloud management software and it makes it very easy to produce usable construction drawings. Simply create a slice through the point cloud with the cutting plane and use 2D Easy Line to produce your linework (set at your preferred threshold variance). The Polyline Tool helps to edit the linework and even arcs.
We can export the file (perhaps as a dwg) and import into the CAD or BIM software of your choice -- we like Trimble SketchUp.
Create 3D Models from 3D Point Clouds Using Trimble RealWorks
Just as it is easy to create 2D construction drawings from the 3D point cloud, we can also start modeling from the point cloud directly in Trimble RealWorks. With the scanned area loaded as a point cloud, we can isolate particular elements for fast modeling. We illustrate how to model three different elements: a steel beam, a run of pipe, and a stair core.
Modeling steel is very easy with the help of two catalogs of steel types and specifications. But Trimble RealWorks helps the process along by fitting the geometry to the point cloud. In the example we show how to segment out the point cloud, select the section type we'll be modeling, and even copy that model so we won't have to model every beam by hand.
Pipes are also straightforward to model using the Easy Pipe Tool. Just extract the points from the pipe you'd like to model and software examines the point cloud to determine the diameter of the pipe and runs along the point cloud to quickly model the pipe.
Again, these elements can be exported out of RealWorks and into the BIM modeling software that's appropriate, like Tekla for steel and concrete, or even SketchUp. These BIMs can then be published to Vico Office for 3D constructability analysis, quantity takeoff, 4D scheduling, and 5D estimating.
Laser Scanning a Floor to Measure Flatness and Level
Today's computerized robotic picking systems in warehouses and distribution centers require racking and shelving to be perfectly square. This means floors that are flat. Not flat to the naked eye -- level and true. And the same exactness applies to sports stadiums and arenas -- you name it. To accommodate these precise requirements, we created a Flatness Routine for our Trimble RealWorks scanning software that allows contractors to view peaks and valleys in the concrete slab and make the required adjustments before interior framing. This video illustrates how.
In Office Survey Mode we have two options: we can either compare a BIM model to the scan of our floor, or fit a horizontal plane to the scan of the floor. Then using the Surface to Model Inspection Tool we can generate a 2D map to see the highs and lows of our floor. We can also analyze the dips and ridges with the Sections and Shifts Tool or use the Differential Plot with an exaggerated scale to see our peaks and valleys. The Isometric Curve feature creates a contour map of the floor for analysis. We can then quickly see the Volume and Surface Comparison for a cut and fill. We can also pick points for manual inspection and export those to our Trimble Robotic Station and shoot those on the floor to locate the exact spots to grind down or fill.
And, of course, we can also use this tool set to measure walls for verticality!
Laser-Scanning As-Built Conditions to Compare to Design Intent
Laser Scanning is not just useful for retrofits and renovations. It can also be used as a quality control step in new construction. Case in point, comparing the as-built conditions to the design intent (either with measurements or against the BIM). We highlight a practical application of measuring steel deflection to see if it affects the clearance of the interstitial space. We show that 10-20 minutes spent measuring critical pieces of point cloud saves hours of on-site labor. We can then export these measurements as a *.csv file for further analysis.
For more information on Trimble Laser Scanning hardware, software, and services, please utilize these resources:
Website: Trimble Laser Scanning
Webinar: Best Practices in Laser Scanning
Dealer Locator: Name the hardware you're interested in and your location to find our authorized dealers in your area