With the recent increase in the use of three-dimensional laser scanners to capture real world conditions, many forward-thinking operators are searching for ways to view, use and manipulate the resulting data. After a laser scan has been performed on an object, structure, or area, the result is a “cloud” of data points that can number into the hundreds of millions. The data points contain information such as geospatial position (exact place in the real world) and the reflectivity of the surface being scanned. There are three main ways that data from point clouds can be viewed digitally:
1. Point Cloud Processing Software– Allows you to view, edit, create, save and manipulate the data. With this kind of software you essentially have your own engineering department. Just add data. These are some examples:
AutoCad Civil 3D
2. Multimedia Files- Most point cloud data can be turned into image files (JPEG) and movies (AVI). These files are great for viewing and visual inspection of the survey and can be opened on any computer. However they cannot be rotated, panned or zoomed, and any measurements or volume calculations still have to be done by hand.
3. Data Viewers- Point cloud data viewers are usually free pieces of software that can be downloaded from the internet and allow you to view your data in a 3D environment. Some even offer a few simple measurement capabilities. Here we will look at two data viewers that use very common file types: DWG TrueView (.dwg/.dxf) and Adobe Reader (.pdf).
TrueView is a CAD viewer from Autodesk that allows you to open and view files that are in .dxf and .dwg file formats. The viewer has some good tools to measure things like distance, angle, area and volume. I have found that data sets up to about 30,000 points work pretty well. Your data provider can filter your data to make it viewable on this platform. If you are trying to work with a larger point cloud or TIN model it can get slow. TrueView works best with a relatively small set of points, but you can also view a triangulated irregular network, or TIN. DWG TrueView:Download
Another way to view models in a 3D space is to use Adobe Reader, version 7 or later. In the reader, you are able to open and view .pdf documents that have 3D objects imbedded in them. The graphic interface is very smooth. You can zoom, rotate, pan, change surface rendering and turn layers on and off, but in the reader there is no measurement functionality.
If you have the full version of Adobe Acrobat, there are a few more useful tools at your hands. In the full version, you can perform distance, perimeter, area and angle measurements. Another very useful feature is the sectional tool, which allows you to cut away part of your model based on any axis, alignment or orientation. Adobe Reader 9: Download
So, whether you want to go free or simply inexpensive, there are some really good tools available for viewing and measuring your point cloud and 3D model data. Your laser scanning data provider should be helpful in getting the right tools into your hands.