Last Updated on 12th May 2021

From SLAM to 3D Model

Laser scanning with Pointknown CEO Jim Foster

Biography

Jim Foster has worked in the surveying industry for over 18 years, building a well-respected company with high-profile clients from all over the United States. Originally the owner of a product design company, Jim saw the opportunity to begin a new adventure in the world of surveying and has never looked back.

Pointknown (formerly InterioReview) provide 2D and 3D documentation with accurate information and digital models, to their clients. In recent years, Jim started using GeoSLAM devices to help capture 3D pointcloud data. The data is then utilised to create precise 3D models in Revit. This workflow has made his turnaround on work quicker and more cost effective.

In this blog Jim talks through his history with GeoSLAM, why he believes handheld scanning is the right tool for his business, as well as a recent example of a project his company has been working on.

GeoSLAM at Pointknown

Back in 2014, a representative for GeoSLAM visited my office with the GeoSLAM ZEB1, claiming the handheld SLAM device was revolutionary in capturing accurate data without needing to use a terrestrial scanner. Due to my initial scepticism, I asked him to complete a scan of my office because I have the measurements down to the 1/16. He scanned the office and processed the data before I could finish a cup of coffee, and I brought the pointcloud into Revit on top of the data we already have. The data was so surprisingly accurate I did not let the rep leave with his demo unit purchasing it there and then, and it was in the field the next day.


We used the ZEB1 for years before purchasing a ZEB Revo, and more recently a ZEB Horizon. Our confidence with the scanners has only ever grown with each new model, and now the vast majority of our 3D models are created from a pointcloud generated by a GeoSLAM scanner.

Handheld scanning Vs terrestrial scanning

When we first started using SLAM scanners, we would still capture the space using our older ways of working, due to the initial scepticism, however we were noticing that the SLAM data could not only be captured significantly faster, but it was also coming in tight. We could have actionable scan data in less than half a day, where it used to take us significantly longer using a terrestrial scanner along with other field methods.

Nowadays, SLAM scanning makes up most of our work and we will only use a scanner alongside the Horizon if a client asks for sub 1cm granularity of data. Our clients are often interested in the output and not so worried about how we get there, so long as the 3D model they receive at the end is accurate for what they need it for – a handheld scanner can deliver that.

SLAM

As I mentioned, GeoSLAM scanners are utilised on most of our jobs, which is fantastic. Due to the rate of capture, my field technicians can work on scanning several projects a day. In addition, because the SLAM scanners are easy to use, I can train new members of the team to a point where we are happy to send them out in the field, very quickly. I no longer need to rely on using specialists trained on a variety of hardware, software and varying field techniques to accurately measure a building for me anymore.

Whether it is as-built survey modelling or 3D laser scanning, the use of GeoSLAM scanners has revolutionised the way we accurately capture space and can assist in helping owners and developers understand their spaces in a quick and efficient manner. Here is a recent example of a scan we conducted using the ZEB Horizon for a house that is due to be renovated.

Chestnut Hill Scan

Scanning with SLAM

As with all our scans, the field technician walked around the property, with the current owner, allowing them to plan their path through the building and figuring out the best way to transition to the exterior. Also, having the field technician walk around the property gives them the opportunity to open locked doors or windows that could interrupt the scan. At this point, we are also thinking about getting the same data from different vantage points, for instance at this property there is a balcony area the field tech was able to walk out onto to capture some exterior parts of the building. Typically for a residence of this size, we would conduct 1 or 2 scans, and this is a good time to the technician to make those decisions.

Once we completed the walk around, the technician sets up the ZEB Horizon and begins the scan of the interior. We scanned the downstairs area first, before making our way to the 2nd and 3rd floor, making sure to scan on the balcony and out of windows over the pool area. We then went down to the basement, and finally finished up doing the downstairs area again. The technician then began to capture the exterior of the building, by walking around the grounds. In addition to the Horizon, we often use a drone to capture pictures from above, which helps the team at the modeling stage.

This is fantastic for the client because we can arrive and scan their property in a short space of time, with minimal equipment.

Processing the scan

When we first began using handheld scanners, we were still skeptical, so we would process the data in the field and take other measurements to compare. We are now at a point where we trust the GeoSLAM devices enough to process the data at our office, with the full confidence that we will not need to re-visit a property.

We process and merge the data back in our office using GeoSLAM Hub and prepared the data to be exported and sent to our production team.

Creating the model

When we’re happy with the pointcloud we will export the data in Autodesk ReCap and then onto Revit, where our production team take over and begin creating the model. The production team will use the pointcloud data to build walls, doors, windows etc. which is the most time-consuming part, but ultimately what is created at this stage is what will be delivered to the client.

You can see the output for this model here: Autodesk Drive

The output

Our Revit models are used by owners, developers, or the AEC community, to help them renovate, build or to typically have up to date building information etc. From a SLAM scan to a 3D model can take approximately 5-7 working days and If I were to use a terrestrial scanner, the overall project would not only take longer but would also be less cost effective for my clients.

Robin Bruna

Jim Foster

Pointknown | CEO