Jay Meszar | Reality Capture Services
3D Scanning is becoming more of a mainstay in today’s engineering projects. The process of 3D scanning is becoming easier, as such, many firms often think they can successfully utilize this technology without proper training. By doing so, they often don’t learn some of the important ins and outs of how to accomplish the little things that ultimately make a big difference in how they work.
Probably one of the most asked questions I get about taking a point cloud into CAD software is “How do I line up my scan with my CAD project?”. To provide an example, I would say the simple answer to this is very much like using AutoCAD which is to set a coordinate system or create and manage a UCS (User Coordinate System). There are two ways to manage and create coordinates of a point cloud in Leica's Cyclone Register 360. This post will cover one of those methods, because I believe it is the most common method people will use.
The image below shows the beginning layout of an office project. If everything was measured correctly, we should be able to line up our point cloud with the linework in the AutoCAD drawing.
Notice how the drawing is rotated to be square with the bottom of the drawing area in AutoCAD. However, when I look at the scan data, the data is rotated based on where the scanner started its first scan.
To fix this so the two line up in AutoCAD, I need to create a UCS in Cyclone Register 360 and reimport the data into AutoCAD. Of course, this can be tricky because I need to make sure the origin location is in the same location. The issue with this is that we often think we just need to rotate the scan and everything will be fine. We need to keep in mind that our project can be at a location other than 0,0,0 and that is where we need to be careful when trying to rotate the point cloud. The cloud can be rotated by selecting a scan location (highlighted in red in the image above) and creating a UCS.
This process is very easy but if we look at the white circle with the plus in it, that is the scan’s 0,0,0 origin point. Importing that scan into AutoCAD will place the white plus at 0,0,0 within AutoCAD. So, in order for us to make this all line up, we need to get the coordinates from AutoCAD and set them appropriately in Cyclone Register 360. Using the ID command in AutoCAD, I can identify the X,Y,Z coordinates that I can use in Cyclone Register 360.
Once I have these coordinates, I simply copy and paste them into Cyclone Register 360. I like to give my coordinate system a name rather than accepting the default. It is important to note, if you are updating the coordinate system in Cyclone Register 360, the data needs to be republished if it has previously been published.
Now that the data is in Leica JetStream, it can be imported into a Leica CloudWorx project. In this example, I am importing into Leica CloudWorx for AutoCAD. Using the Open JetStream button on the Leica ClouWorx ribbon panel, and then clicking the ellipsis button to select the project (already done in the image below). Notice the named coordinate system is selected under Coordinate System in Point Source.