I have a facility with 180 scans, broken down into 1st Floor (70), 2nd Floor (50), Roof (30)and Exterior (30)
About 1/2 of the scans are 1/2 Resolution x2 Quality w/photos
The other half are 1/4 Resolution x3 Quality w/no photos.
I pulled in all of the files, pre-processed them and pre-clustered them based on the four main divisions, listed above.
Processing
Typical Processing Settings:
• Create Scan Point Clouds: Yes
• Skip Fully Processed Scans: Yes
• Colorization: Yes
• Filters: Yes (Threshold 200)
• Distance Filter: Yes (0-656ft)
• Stray Point Filter: Yes (3px , 0.07ft, 50%)
• Edge Artifact Filter: Yes
• Find Targets: Find Spheres (If Applicable)
• Perform Automatic Registration: No
I looked up the S120, that has a range of 0.6m-120m. Which is roughly 400 feet, so it is clear that my distance filter could be improved by making this at a minimum, 400 feet rather than 656 feet (default)
Is there a better distance to set this filter at? I understand accuracy of the scanner drops, the greater the distance, and it will depend on the tolerances we are comfortable with. However the building we scanned has 225 feet as the longest side, which means at 400 feet, the vast majority of our scans have the potential to have shared points from all of the scans (if there were no obstructions, theoretically)
Also what is the difference between Processing Distance Filter and Point Cloud Distance Filter? Is the point-cloud distance filter just there, if you didn't use the distance filter in processing? Or wish to narrow your distance later? If you were to make both distance filter numbers the same, there would be no change, correct?
Registration
In a broad sense, My process is to get all the scans laid out correctly with a quick-correspondence view, and then "refine" the registration by using Cloud to Cloud, which I typically do multiple times; Default of 32ft, then I re-attempt at 3 feet and then at 0.3 feet, In other jobs I've gone as far as .01 feet. Ideally each time, I look at the Overall Statistics % under the Scan manager - Scan Point Tension tab, and shoot for an improvement (a higher number) each time. Occasionally the number gets worse and I revert back to the previous save, and consider that cluster finished. (I know that isn't the best metric to use, open to suggestions, we are self taught here)
This project used targets, so I attempt an automatic reg based on targets, I get clusters within my clusters now, and by either manual registration (I actually quite like this option) or Visual via correspondence view, I have gotten the four clusters to appear correct, or within initial placement/reason. I've got green lights on my overview for registration, the scans look pretty good as I shuffle through them.
What level of inspection and how do you all go about it, on the registration step? Do you look very close at each and every scan? I can tell in correspondence top view, when a scan is roughly in the right spot, and I thought the cloud to cloud would tighten them up, and it usually does, but when I end up in Recap/Autocad and we begin to model from the point cloud, we notice sometimes that a scan is very poorly registered. I've found it very hard to notice these issues, when in scene. Do I just need to take more time to inspect things closer?
Can I use the Registration Report to note scans that are red, and visually check them one at a time? I've been hunting all week for some video or post to explain exactly what I'm looking at with the registration report, and what to do to improve it. Some forum posts say that it's garbage, but my boss doesn't like that excuse, I know that red must be bad and green is good, but hell if I follow much more of it outside that.
As for the subject of the thead: When I have 1st and 2nd floor, clustered and registered correctly within themselves, and I want to now "combine" the two floors, I've got some decent overlap with doorways, stairways, chunks of the floor gone, etc. Should I lock the clusters before registering them together? My team seems to be in the camp of getting them close, locked, but when refining them, to unlock it so the scans can all move a little if needed, to get the best fit. The worry we have is if they are both locked, that you can get a 2nd and 1st floor that are correct on one end, but wrong on the farther end, Im not explaining this all too well, but can't seem to find a good argument for one way or the other.
Point Cloud Creation
These are the settings we typically stick with.
- Eliminate Duplicate Points: Yes
Search Radius: Medium
Close Surfaces: Yes
Full Color Detail: No
Homogenize Point Density: No
Apply Color Balancing: No
Distance Filter: 90m
Also would like to complain about the "disk space needed" portion of the point cloud creation window, mine will frequently tell me it's got enough space yet fails after 15 hours of processing. We are grabbing a new 2TB SSD to remedy this, but it's bitten me in the ass a few times, I've found FARO websites suggesting a mix of 2-4 and like a 4-7x free space of your scan data files, so we are flying with a 11x scan data space needed, but that just seems like such a vague answer. Also which file size is this based off of? My FLS Scans on the scanner SD card is smaller than the FLS scans in the scene folders, and is that even the correct spot to pull the size from?
I can post some pictures of the project in particular in a bit, let me grab some useful screen shots.