We get asked a lot if it is possible to use PointCab results in BricsCAD. The answer clearly is YES. We have prepared two videos to show you how to easily import PointCab Layouts and Sections and also 3D-Meshes (digital 3D terrain models) into BricsCAD. See how the pointcab Tools work and start using laser scanning data and point clouds in BricsCAD. If you have questions please feel free to contact us under at: firstname.lastname@example.org. Here you can get to the PointCab modules and Tutorials.
Layouts and Sections in BricsCAD
3D-Meshes in BricsCAD
How Do I Position a Laser Scanner to Scan a Façade?
Correctly positioning a laser scanner is an essential prerequisite for obtaining a complete and meaningful point cloud. In the series “True Laser Scanning” we make notes on the fundamental points for excellent scanner use. In this article we cover choosing the optimal laser scanner positions when scanning oversized facades.
A laser scanner can detect only that which is visible from the scanner center. We advise our customers to “Look through the eyes of the scanner”; all you can see with your eyes is identical to what is detected by your laser scanner and shown later in the point cloud. You will quickly find that you cannot look behind objects or around corners ;).
Accordingly, it is always advisable to view your intended target from different laser scanner locations; for complex, high-detail facades it is always better to scan too much rather than too little.
Avoid horizontal shading
Consider a wall in plan view. In the example shown, you can see quickly (see green circle) that left rear corner and the left window reveal is not detected by the laser scanner. Accordingly, a further laser scanner location is required for the detection of the left jamb.
In the following picture you can see how the shaded areas are detected by the second (blue) scanning position. A large part of the facade will be detected with the second scan position, and combining the two will give you a higher density of the point cloud and thus better detailing.
Also consider vertical shadows in the laser scanner sighting
Issues of vertical shading also occur in the scanning process. Imagine the following scenario.
Using a scanner with a low elevation will throw a “shadow” onto the lower half of the window. In order to obtain a full detailed scan of the window, raise the scanner on a tripod or elevated platform until it is roughly the same height as the center of the window; this will ensure an accurate point cloud rendering.
Please take notice of our article: True Laser Scanning – Part 02 Correct Laser Scanner Resolution
Today we would like to show you how to create Meshes from your building walls using your laser scanner point clouds. Here you find this posts example laser scannin data.
We start with a simple wall which you can see in the following scan (scan facade 15).
After importing your point cloud data you will see the automatically generated standard views. First of we adjust our project settings. Therefor you go to Data –> Settings and activate the Mesh tab and set the Mesh accuracy to 0,001m aka 1cm and the median filter to none. Then press ok.
Now we define a section in the top view:
- Define the section a bit larger than what the wall is. The exact area for the mesh will be defined later.
- Position the Section line (red dotted line) exactly on the wall line.
- Define a small clipping box area(yellow area). In our example it is 3cm in front and after the section line.
- For a detailed reproduction use a 5mm resolution.
Open up the front view and adjust the section hight. Again we adjust the clipping box to be a bit over the the seiling and floor.
Start processing the section job and open the results by right clicking the section job and choosing open.
Now you see the section orthophoto. Details, like the wall plugs and the window reflections, can be clearly identified. We start defining our mesh. By pressing and holding the SHIFT button we can create axis-parallel lines.
Activate the Mesh tool and define the Mesh lines exactly on the outer wall corners. To be better able to understand the settings afterwards you should now set the mesh accuracy to 5mm and the filter to 0cm and start processing the mesh.
Aftzer the processing is done you can see the many mesh points displayed in your section orthophoto. Open up the 3D view of the Mesh result by clicking on it with a right click again and choosing open.
Open the 3D view.
You now see that there are some distraction points in your results. You can now simply edit and adjust the detail settings of your Mesh Job to get a more harmonized result in the end:
- Mesh accuracy 1cm – means that only points sticking out more than 1cm create a new mesh point
- Filter Objects 5cm – All distractions with a samller footprint than 5cm x 5cm will be filtered.
Every time you edit a previously processed job the data will be lost buit the settings will be kept. This way your result folders stay lean even hough you keep creating new results.
You find all your 3D results in the folder Project_Results3D.
Next to the formats DXF and DAe we have only created a DWG file for this example. The file has a size of 65kband can be easily used in any CAD system. You can download the example file here.
Here you see the file loaded up in Autodesk DWG TrueView.
You can find further tutorials under: https://www.pointcab-software.com/en/support/tutorials/