Explanation of Negative Deviation Values in Tunnel Deviations
The appearance of negative deviation values in certain sections of your tunnel model is due to inconsistencies in the orientation of the tunnel geometry faces, which stems from the way the file was originally exported. Example:
Problem Origin
In your file:
Some faces of the tunnel geometry are oriented inwards toward the tunnel center.
Others are oriented outwards, away from the tunnel.
This lack of consistent face orientation causes the deviation analysis to interpret the direction of the geometry incorrectly, resulting in unexpected negative values.
Our Solution: Fix deviations where geometry is flipped
To address this issue, we have introduced a new feature that allows manual correction of face orientation:
You can now specify a radius that defines how far from the centerline the software should consider faces to be flipped inwards toward the tunnel.
This correction aligns the geometry properly relative to a given centerline, ensuring that deviation values are calculated consistently and correctly.
Important Usage Notes
A centerline is required to use this flipping feature.
If your model contains two or more tunnels in close proximity, take care when setting the radius:
A radius that is too large may unintentionally influence the geometry of neighboring tunnels.
Make sure the entered radius is just enough to encompass the intended tunnel and no more.