Can someone please share the method of doing the scan of a large object. I want to scan all the markers first and then do the scan. When you select global markers from the software, do you scan the first five markers, then press pause, move the tracker then press continue until you have measured all the markers, then press cloud scan to start the scan. I tried, but got a scan with definite errors in the model.
With the normal method using the manual, it does not quite make sense. If you have five markers in the first group of markers, then when you move it, what is the minimum number of common markers from the first station must be included in the second station?
In the example video of scanning a car, they did the global markers first, but did not give an indication of what they were doing with the software.
Logically, to me, there should be a reasonable number of common markers between the setup stations that are common to extend the scan and not add errors by using short baseline of points to base the second scan on.
If using the marker blocks supplied with the scanner, and say putting them on the side of a vehicle. If you set the scanner looking from the front of the vehicle to the rear at an angle to extend the scanning area, the you are looking at one side of the marker blocks, if you then move the tracker towards the rear, then you are looking at the other side of the marker blocks that was not visible in the first scan. How do we avoid this? Would it not be a good idea to be able to scan the other side of the marker blocks when doing the scan and include these in the global marker file. You could then include the markers on the shadow side of the marker block in the calculation, enabling you to use them on the next setup.
any advice would be appreciated
You can track your way around a large object just by the included magnetic markerballs. You dont have to collect all the markers at once before scanning and create a regular global marker type of situation, that is why the guys referred to this as leapfrogging earlier. Basicly what the “next stop” button and cloud scanning buttons do is switching the scanner between markerpoint collection by the tracker and pointcloud collection by the handheld scanner. In which ever mode you are in, it takes the already collected data and adds more data to it. So if you are in next stop mode, it takes the existing markerpoints data and adds new points to it whenever it sees a new one. When you finish and click cloud scan mode, it locks the markerpoint data and opens up the pointcloud data to expannd with new points. Also, that is why it is mandatory to keep the handheld unit outside the trackers view while collecting marker points, otherwise the reflective points on the handheld unit would register as unintended markerpoints and would create chaos.
Lets assume you want to go around the object from left to right. You place the balls along the way, I believe even if the tracker only sees 3 balls, there are enough markers on them to meet the minimum number of points, but I would place them so that at least 4 of the balls are visible to the tracker at any given time, while they are as far apart as possible. you got 6 balls with your scanner, you place them in 2 rows and 3 columns along your object. you collect all of them, click point cloud scan and scan the area. Then you can move the left column of balls over to the right side, same column spacing as before and then click next stop, and move the tracker to the right, along your object. You can collect the markerpoints while you physicall move the tracker, it doesnt have to be stationary whille marker collection is active. It probably even helps to better keep track, especially in case you move enough to see the other side of the balls, like you mentioned.
the tracker sees and aligns to the 4 balls you kept in place and collects the other two balls you just moved and locked to a new position. now you can click cloud scan and return to scanning the now newly visible area. When done, you repeat the process and go around the object until complete a full circle.
It doesnt matter that you re-use the balls again and again because you move their position to new coordinates so the system will register them as new markers, while their original position will still be visible on the screen, but greyed out, as they cannot be seen by the tracker anymore.
Same method applies if you just change the angle and positioning of the tracker but you generally scan the same area, although in this case, you dont have to move the balls at all. Hope this helps!
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Thanks. I appreciate the detailed response