Visualizing Point Clouds
Written by Paul Tice   
Saturday, 29 April 2017

A 1.558Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

3D laser scanning has evolved over the years, beginning simply with developers trying to figure out a way for computers to be able to handle this robust data. As technology has improved, this industry has innovated to produce lighter and easier to handle 3D point models. In addition to that, 3D point data visualization technology has dramatically improved as well.

Not only has the hardware improved to create cleaner and crisper scan data free of extraneous noise, commercial software such as FARO Scene has improved to crunch billions of points into a 3D viewer that can read hundreds or thousands of point clouds at once with little lag in 3D navigation. Project Point Cloud has been a remarkable point cloud viewing innovation. It lightens the point cloud model for ease of movement and also balances all the colors of the scans for a very comprehensible viewing experience.

The Costs of Project Point Cloud
That being said, Project Point Cloud (PPC) can really cook your graphics card--which may look like screens going black if users attempt too many operations at once such as navigating and then taking a measurement in 3D. Therefore, it's pretty important for users to ensure a top-of-the-line graphics card (2 or 3 daisy-chained together is optimal) is available to even consider having a pleasurable experience while multi-tasking.

If you're new to point clouds, you may want to check out my other blog on computing recommendations for the Scan-to-BIM workflow.

Another cost for this valuable PPC tool is time. We have found that it takes sometimes several days for the algorithms to produce PPC in FARO Scene software for large projects. If you have the time however, we highly recommend this process. We do however understand that it can be tough to justify this time since most designers are most interested in getting the data directly into BIM software for as-built verification as quickly as possible. Most of our clients opt out of using the FARO Scene LT viewer unfortunately. Until FARO allows feature extraction directly from PPC, or perhaps some other mechanism for the superimposition of BIM models with the point cloud for as-built verification, it could remain a visual gem that may be too expensive (in terms of time) to wait for. To date, FARO Scene only imports VRML (.WRL) models which would require standard model types to be converted. We have not yet tested whether converted and imported BIM models in .WRL format retain their coordinate systems through this workflow.

An Autodesk Workflow
Some things to consider with exporting PPC from FARO Scene: This high-grade, visually appealing and color-corrected data cannot usually be successfully exported all at once for large projects; although this is offered as an option in FARO Scene.

For projects having a few hundred scans or more, your computer will most likely run out of memory before the export is complete. Alternatively, FARO Scene will crash. There is no way to break up the PPC data other than "MultipleClippingBoxes" . While this is a good option, there is no option other than ASCII format for export from clipping boxes as the speedy .FLS file type export option is not available. This leaves users the option for either very small and numerous, MultipleClippingBoxes that are adjacent to one another to speed up the ASCII export a tiny bit, or just clipping good sized chunks of the overall PPC and wait it out. Either way, users will be waiting 15-30 minutes for each clipping box to export. Also, there is no way to automate this workflow with off-the-shelf Scene. (Could be a nice development for the FARO App Store though.)

A suggested workflow is to just export clipping boxes from PPC in FARO Scene that are large enough for BIM modelers to work, without having to jump in and out of the Point Cloud manager of their BIM platform. A room sized clip for example would be appropriate. While it may take up to 30 minutes to generate the ASCII file (we use .PTS), users will find relief when these massive ASCII files (up to 30gb each) are indexed in ReCap. Recap will handle these files well and crunch them down to about 300mb or so as ReCap has a built-in decimation feature by default. This is a great way to cut hundreds of scans by about 1/3 and reduce the overall project file size in kind. Most of the important detail will be retained after this native decimation and the ReCap converted point cloud clips will sport several benefits:
• File size reduced by 1/3rd or more.
• 1/3 less point clouds to manage in BIM software.
• PPC files generated from clipping boxes allow modelers to see all scan data in the room from all vantage points rather than trying to hunt for the right scans to fill in the occlusions (that is if users have a low powered computer and are required to turn off and on point clouds to optimize computer performance).
• PPC files converted to ReCap in this way are color-corrected.

And Now for Something a Little Different...
Other companies have tackled the point cloud viewing problem such as Euclideon which developed the Unlimited Detail algorithm; essentially `baking' rather than rendering the point clouds. This was a phenomenal leap in point cloud viewing, allowing (theoretically) hundreds of thousands of point clouds to be viewed at once with no computational lag. A brilliant idea, but the cost at one point of sending them your data to `bake' was upwards of $60,000 USD (based on a call I had with a rep there about 5-6 years ago). I cannot imagine anyone willing to pay that in the construction industry, but perhaps in the entertainment industry that would not be a large stretch for a realistic game or movie environment... To date, the prices for this service have dropped dramatically, allowing wider adoption of this technology.

This is such a revolutionary concept that we at ToPa 3D believe our next statement should be emphasized:
"If Euclideon can animate point clouds as demonstrated in the video above, then it should be possible to assign metadata to each point with said data hosted perhaps as IP's in the IoT. And, if that's possible, then we at ToPa believe that one day, component and mesh modeling will be antiquated because intelligent models of the future will be composed of pure point cloud data."

Perhaps one day we will be famous for that quote--that is if mom tells her friends on pinochle night...

In conclusion, we hope this has opened your mind to the possibilities that await this exciting industry (if you haven't been digging too deep already). Imagine entire planets surveyed with LiDAR and viewed in real time...yay lazers!

ToPa 3D is a leading 3D Scanning, 3D Modeling, and Visualization firm in the Pacific Northwest, leveraging the latest in 3D reality capture technology. To contract with us on your next project, contact ToPa 3D, This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ,

Drawing from over 20 years of experience with GIS and CAD projects, Paul Tice the owner of ToPa 3D specializes in building technical teams and provides training for firms augmenting their existing workflows with reality capture technologies.

A 1.558Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE