Cover 3 Ways To Tackle With Point Clouds

September 10, 2020

BIM QA/QC with point clouds

Now more than ever, AEC professionals need access to an accurate representation of on-site reality. 

Once a reality capture has been taken, teams are able to run construction and as-built verification remotely without having to step foot on site. 

However, you’ll still need a robust BIM QA/QC process to detect and fix discrepancies between the model and reality. 

A QA/QC workflow using laser-scanned point cloud data

Fig 1. A QA/QC workflow using laser-scanned point cloud data. 

This blog post takes you step-by-step through 3 different workflows using scanned point cloud data for a better BIM QA/QC process. 

Check out the video summary below, and enjoy the read! 

Laser scanning for all!

Reality capture is a powerful technology that is becoming increasingly accessible due to falling laser scanner prices. 

Not too long ago, buying a standard laser scanner could set you back somewhere in the region of $200K. Now, you can pick up a basic model for around a tenth of the price. Even better, rapid technology advancements are also helping the adoption and ROI for implementing laser scanners onto a project site.

Example laser scanners from left to right: Leica BLK 360, Trimble TX6, Topcon GLS-2000

Fig 2. Example laser scanners from left to right: Leica BLK 360, Trimble TX6, Topcon GLS-2000

Don’t get us wrong, if you still want to spend big bucks on laser scanners, you can! Check out the award-winning Leica Pegasus backpack scanner, which can capture an entire site using 360° and long-range scanning while you walk around it.  

We’re just saying, you don’t have to spend hundreds of thousands anymore to get a decent level of accuracy.    

We really are starting to enter a universe where it’s actually affordable to do a more robust QA/QC process. That’s because whether it’s hardware or software, all the tools that filter into this reality capture-based QA/QC ecosystem are much less expensive.” 

Kelly Cone Kelly Cone,
“Coordination, Issue tracking, and QA with BIM Track and Verity” webinar.

3 point cloud-based BIM QA/QC workflows 

Let’s get into the juicy details. Here are 3 ways to tackle your BIM QA/QC process using laser-scanned point cloud data using laser-scanned point cloud data in platforms like Navisworks, ClearEdge 3D Verity, and Cintoo Cloud. Are all workflows created equal? We’ll leave you to be the judge of that, but we hope you find a workflow you can see yourself putting into practice. 

1Clash detection with point clouds: Navisworks 

This basic workflow is good for comparing as-built point cloud data to the federated design model in a familiar environment. Navisworks can import point clouds, though it is slightly limited to working best with proprietary .rcp or .rcs file formats through Autodesk point cloud platform Recap. You can also use plug-ins where available to import scans directly from laser scan platforms, such as Leica CloudWorx for Navisworks. 

Fig 3. A QA/QC workflow for running clash detection with point clouds in Navisworks. 

Workflow images courtesy of BAM Construct UK.  

    1. Decide on the area, level, or system, you want to check and load the model in Navisworks. You can use the selection tree to hide any irrelevant parts of the federated model. 

      Loaded federated model requiring the QA/QC process in Navisworks
      Fig 4. Loaded federated model requiring the QA/QC process in Navisworks. 
    2. Import point cloud data into Navisworks in .rcp or .rcs format, or through a plug-in, and make sure it’s aligned properly.
      mported and aligned point cloud data in Navisworks
      Fig 5. Imported and aligned point cloud data in Navisworks.

    3. Open the Clash Detective tool and define a clash test, eg. “Design MEP vs Scanned Steelwork Area A” and select the point cloud and model in “Selection A” and “Selection B.” Working with point clouds, you’ll have to specify the clash test as a “clearance” test, and choose your tolerance. Then, run the test! 

      Defined options and clearance for clashes in Navisworks
      Fig 6. Defined options and clearance for clashes in Navisworks. 

    4. Review clashes and raise any issues for resolution.

      Clash test results being reviewed to identify issues in Navisworks
      Fig 7. Clash test results being reviewed to identify issues in Navisworks. 

    5. To complete the QA/QC workflow, you can use BIM Track’s Navisworks Add-in to turn Navisworks clashes to issues, then allow the design team to access and resolve them directly in authoring platforms like Revit or Tekla Structures in one click: 



      2Automated as-built verification:
      ClearEdge 3D Verity 

      ClearEdge 3D Verity is a specialized Add-in to Navisworks which automates the as-built verification process using scan to BIM comparison. It’s also great for construction verification to check installation status and accuracy against the design / fabrication models. Verity will run a quality check of the whole model, and find any areas which are problematic or out of tolerance. This kind of automation will really speed up your QA/QC workflow, and leave you with more time to keep project coordination on track.

      A QA/QC workflow for automated as-built verification with ClearEdge 3D Verity.

       Fig 8. A QA/QC workflow for automated as-built verification with ClearEdge 3D Verity.

      Workflow images from webinar “Coordination, Issue tracking, and QA with BIM Track and Verity”.

      1. Load the point cloud and the model into Navisworks.

        The model and point cloud aligned in Navisworks with the ClearEdge 3D Verity Add-in
        Fig 9. The model and point cloud aligned in Navisworks with the ClearEdge 3D Verity Add-in.

      2. Run an initial analysis using Verity, which will run a “first pass” quality check on the whole model and let you know whether things are within tolerance, out of tolerance, or missing. Performing this quality will give a really good indication of the overall status of the model or on-site construction progress.

        An initial QA/QC analysis in Verity identifies passing, not found, occluded, and out-of-tolerance elements at a glance.
        Fig 10. An initial QA/QC analysis in Verity identifies passing, not found, occluded, and out-of-tolerance elements at a glance. 

      3. Inspect objects flagged as out-of-tolerance in Verity. The automated list of problematic elements still needs some review to see which issues need addressing. 
        An inspection of out-of-tolerance elements detected by Verity during an in-depth QA/QC process
        Fig 11. An inspection of out-of-tolerance elements detected by Verity during an in-depth QA/QC process. 

      4. Create a QA/QC report to share with collaborators in CSV format (Excel), or HTML format with images. 
        Verity users have the option to share a QA/QC report with stakeholders via CSV (left) and HTML (right) format
        Fig 12. Verity users have the option to share a QA/QC report with stakeholders via CSV (left) and HTML (right) format.                                 
      5. You can also export colorized point clouds of specific elements to send out in smaller packages, save colorized Navisworks properties, and automatically update the Naviswork model with as-built conditions. 
        Export point cloud data for specific elements, save colorized Navisworks properties, and automatically update the as-built model with Verity
        Fig 13: Export point cloud data for specific elements, save colorized Navisworks properties, and automatically update the as-built model with Verity. 

      6. Once you’ve found things that are NA or out of tolerance, you can bulk publish the Verity variance data as BIM Track issues using the ClearEdge 3D Verity + BIM Track integration

      3Collaborative scan-to-BIM comparison:
      Cintoo Cloud

      Cintoo Cloud is a cloud-based platform which takes your BIM QA/QC process online for a more collaborative experience. You can use Cintoo Cloud to upload and download laser scans, organize scan data into different work zones, and then export a single scan, crop, work zone, or whole data set as a point cloud or unified mesh. Cintoo Cloud’s high resolution unified mesh format allows hefty point cloud data to be manipulated and shared more easily. The web viewer allows you to compare as-built scans to the BIM model to perform visual checks. What this workflow lacks in the automated model-checking capacities of Verity, it makes up for in web-based flexibility and great visuals. 

      A QA/QC workflow for online scan-to-BIM comparison with Cintoo Cloud

      Fig. 14: A QA/QC workflow for online scan-to-BIM comparison with Cintoo Cloud.

      Workflow images from Cintoo.com.

      1. Load the model and laser scan data into Cintoo Cloud’s mesh based viewer. If the scans and the BIM model are not in the same coordinate system, Cintoo Cloud provides an alignment tool for this purpose.

        Fig. 15: Models and laser scan data loaded in Cintoo Cloud’s online mesh-based viewer.

      2. Open the “Compare” tool and select the scans and models for comparison. (NB: The same comparison tool can also be used to compare two sets of scans and monitor construction progress.) Use the “Visual Difference” tool to colorize the scan and model in a “heat map” to help you detect misaligned or out of tolerance issues in a visual BIM QA/QC process. 

        Fig. 16: Comparison of laser scans with the model in Cintoo Cloud using its colorized “Visual Difference” tool. 

      3. You can also use the “Visual Check” tool to adjust scan and model transparency to check each together or separately from the exact same viewpoint. 

        Checking models against scans in Cintoo Cloud using its “Visual Check” tool
        Fig. 17: Checking models against scans in Cintoo Cloud using its “Visual Check” tool. 

      4. During the visual QA/QC process, you can create issues in the viewer as you detect them.

        Creating issues during the visual QA/QC inspection process in Cintoo Cloud’s online viewer
        Fig. 18: Creating issues during the visual QA/QC inspection process in Cintoo Cloud’s online viewer. 

      5. To share issues, you can either export them as BCF files, or publish to BIM Track using the Cintoo Cloud + BIM Track integration. From here, the design team will be notified, and able to access the issue in their authoring platform to update the model immediately. 

        Cintoo Cloud users can publish issues to BIM Track, with a URL linking directly to the issue location in the Cintoo Cloud viewer
        Fig 19: Cintoo Cloud users can publish issues to BIM Track, with a URL linking directly to the issue location in the Cintoo Cloud viewer. 

      For a full walkthrough of how to perform visual QA/QC using Cintoo Cloud, check out this clip from our joint webinar: 

      Thanks for reading through our 3 QA/QC workflows using point clouds! We hope you picked up some tips for improving your off-site QA/QC process during a challenging time.

      If you haven’t already, try BIM Track free and put it to work straight away, or talk to an expert to see how you can set up a successful remote coordination workflow. 

      Louisa Fletcher

      Content And Community Specialist

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