Frequently Asked Questions

This page will cover frequently asked questions from Collage Site users, and answers to those questions.

General

Question 1:
Are there certain characters I cannot use when creating a project inside of Collage Site?
Answer:
Special characters like !, @, #, ?, as well as spaces cannot be used when naming a new Project in Collage Site. If you have one of those characters in your project name, the outline of the naming dialog box will turn red until you remove it.

Question 2:
What does the Clear Collage Site Cache tool do?
Answer:
This is an advanced technical support tool that is used when you are experiencing issues while attempting to update your Collage Site to a newer version.

Licensing

Question 1:
What do I need to do when I encounter the “Offline licenses should be validated online” licensing error code?
Answer:
Collage Site license validation currently requires your device to be connected to the internet at least once per month. If you run into this error, please connect your device to the internet and launch Collage Site.

Linking

Question 1:
When should I use C2C and Linking workflows? What environments are suitable, and which are not when it comes to using C2C?
Answer:
C2C is most likely to SUCCEED when:

  • There are multiple characteristics of the scan data that have overlap. Things like walls, pillars, pipes, equipment, etc. can help Collage Site match scans up accurately.
  • There is significant overlap of scan data between multiple scans you have performed.

C2C is most likely to FAIL when:

  • Objects like moving cars, moving people, and construction equipment change their position and/or shape over time
  • Scanning areas like corridors or tunnels that have similar features/patterns over a large area

Question 2:
How far away from each other can my stations/scans be if I want accurate C2C results?
Answer:
This will be dependant on the settings you use when performing scans, along with a few other variables. That being said, the best practice is to set up your scanning instrument so that the scenery around it does not significantly change between two stations you are trying to Link and use C2C with. For example, if you are performing scans indoors, place the scanning instrument a few steps away from things like walls and columns instead of right next to them. This gives the instrument more room to work with when picking up data, and will give you a better chance of having significant overlap between scans. It is also important to note that it is imperative to perform scans at entrances/exits from rooms, in the doorway. This will help the scans performed in separate rooms ultimately have more overlap and be easier to link successfully. In general, setting up the instrument at 5 meter intervals or less will ensure sufficient overlap and increase the success rate of C2C and Linking in Collage Site.

If C2C fails while you are using the sparse, low density scans in your Collage Site project, please try the following:

  1. After adjusting the position and rotation of the data by using Manual Initial Alignment, run Quick C2C.
  2. Upgrade low density sparse scans to full resolution data using the Upgrade Sparse Scans workflow, then try performing C2C again.
  3. Perform additional scans if possible, gathering data in areas you were previously working so that there is greater overlap between all of your data.

Question 3:
How do I know if my C2C results are good?
Answer:
The first things to take a closer look at are the distance (RMS), Intensity, and Overlap metrics - these represent the overall result of how well Collage Site was able to perform C2C and align the scan data you are working with. Ideal values are as follows:

  • Distance:
    • Auto Initial Alignment: 20 cm or less
    • Quick C2C in Place: 5 cm or less
  • Strength: 70% or greater
  • Overlap: 40% or greater

Question 4:
How can I create “loops” that are recommended for optimizing my results using Optimize and Bundle Adjust?
Answer:
The optimization process will work best with more links in a project, however, C2C results must be favorable at each one of those links. By creating both large and smaller loops between stations in your projects, it is possible to distribute the error accumulated by our C2C algorithms appropriately over all of the data in your project.

Example of loop creation between stations

Additionally, loops are not always going to be circles. Take the screenshot below as an example - if links are create going from stations 1-2-3-4, you will create a straight line with no loop. However, you can simply add a few additional links (1-4), (1-3), and (2-4) to create a loop.

No Loop

Loop created



Question 5:
I have two scans that were performed either right on top of each other, or very near each other. They look like they have perfect overlap, but my C2C metrics are still showing them with only about a 60-70% overlap - why is this?
Answer:
Currently, the rough method of calculating that overlap is taking the number of correspondence points in the scans and dividing that by the total number of points. It is impossible to calculate the corresponding points perfectly between two scans, so Collage Site is making predictions as best as it can. Collage Site then filters the corresponding points in order to make that prediction as accurate as possible, but because it is filtering quite aggressively, only correspondent points with high certainty remain. Because of this, even point clouds that are scanned and generated from the same exact position will have lower overall overlap than they actually have.

Import/Export-Publish

Question 1:
Can I check sparse scans in Collage Site and process a scan project stored on the SD card in MAGNET Collage?
Answer:
No, this workflow is not currently supported. You need to export a scan project as a MAGNET Collage project after upgrading sparse scans in Collage Site.

Question 2:
Why is my FBX model that I created in Revit and imported into Collage Site not aligning with my control points in the main viewer?
Answer:
Revit coordinate systems, in general, can be very complex. We are working on a fix for using Revit generated FBX models that will be implemented in the near future. In the meantime, you can simply create the reference model in Navisworks and then immediately import that model into Collage Site.