Scan Orientation Changes When Exporting from SCENE into 3rd Party Software
This problem occurs when the over-all orientation of a set of scans was done by manually applying a transformation to the scans folder.
Transformations entered into a folder of a workspace “belong” to the workspace and not to the scans. You could even have nested transformations if you have folders within folders and each of it has a transformation defined.
Only the transformation matrix of scan can be stored in the scan file. So, if a 3rd party software reads FARO® scan files, it does not know about any transformation which may have been defined in the workspace. Accordingly the scans will not be aligned in the same way as it was within SCENE.
There are 2 general solutions to achieve the same alignment in 3rd party software as in SCENE:
Manual solution (cluster registration only)
- Pick one scan and rotate it manually (with the transformation of the scan) until it is aligned as needed.
- Mark this scan as Reference (in the properties of the scan - scan becomes marked with a pin needle in the tree view) thus this scan will not be modified when placing the whole set of scans.
- Select Place Scans of the scans folder all other scans will be placed around the reference scan and thus be aligned in same way.
Using References folder
- Look for objects in the scans like perpendicular walls which are parallel to the desired coordinate system. Have SCENE fit objects on it.
- Right-click on the objects (within one scan) and select New - References this will create a copy of the object in the References folder of the workspace.
- Modify the objects in the References folder as needed (i.e. assign normal vectors like 1, 0, 0 (wall along Y axis) or 0, 1,0 (wall along X axis) or 0, 0,1 (floors). At least 3 planes or 3 points or suitable combinations are needed.
- Cluster registration: good enough to have objects from one scan. Should even work if the objects are distributed over several scans (within one cluster).
- Old-fashioned registration: the created references need either to be visible in all scans or you have to define more references to have at least 3 references per scans existing in the “References” folder.
- Select Place Scans of the scans folder or place each scan individually. The scan will be placed according to the given coordinates and normal vectors in the References folder.
After saving the workspace, the correct orientation is stored in the scan files and 3rd party software will display the point clouds at the correct positions and orientation.
Keywords: orientation, orient, scans, faro scans, third party software