Point Clouds can be scaled outside of Reconstruct and imported into design software for further design work, and creation of as-built BIM models. In this example, we will use Cloud Compare (to scale the point cloud), Autodesk Recap (to convert the scaled point cloud) and Autodesk REVIT (to create BIM), but please note that these functions are not exclusive to these software's.
1. In Reconstruct, Measure the distance of a scaled/calibrated model, making sure to pick points in areas that are well sampled (lots of points).
Hint: Pick points that are as far away from each other as possible. The longer the scaling dimension (relative to the overall point cloud size), the smaller the error in scaling is.
2. Go to the Data Manager, and the Point Clouds tab, select the Point Cloud and select Download. In the Download Menu, select the option to download the original Point Cloud. The point cloud is in .las format, and is usually unscaled when exported from Reconstruct.
3. In Cloud Compare, Open the Point Cloud.
4. Select the Point Picking Command.
5. In the Point Picking tool, select the “Select 2 points…” command.
6. Select the same two points as were selected in Reconstruct. The distance between the points will be shown in meters. This is the unscaled dimension.
7. Calculate a scaling factor with which to scale the point cloud using the formula below:
Scaling Factor = Field Verified or Desired Dimension/Unscaled Dimension
8. Select the point cloud in the DB Tree, and then in the Multiply/Scale command (Edit > Multiply/Scale) type the calculated value for the Scaling Factor in the Scale field.
9. Select the Point Cloud in the DB tree and Save it with a new name.
10. In Recap, Create a Recap Project, and select the now scaled Point Cloud for Import into Recap. In the Scan settings page, make sure to set the intensity clipping at 100%. This will import the entire point cloud as is without Recap filtering out any points.
11. Select Index Scans, and Launch Project.
12. Once the point cloud loads, select Save As to save the Recap Project in a location of your choice (with the .rcp extension).
13. Create a New Project (or open an existing project).
14. In the Insert > Point Cloud command, select the .rcp file saved from Recap.
The scaled point cloud from Reconstruct should now be imported into Revit for further use in creating as-built BIM models.