I get an error message saying "A self-intersection was detected" when I try to generate the unstructured mesh by TetGen - see Fig. 1. Why?
Fig 1 - Error message "A self-intersection was detected"
The error may be triggered by the intersection of geometries.
There are two types of intersections not allowed in the TetGen mesh generator - see Fig 2. and Fig. 3. Unfortunately, if this is the case, you must go back to your geological software and repair the surfaces there.
Fig. 2 - Example of intersection not allowed in the TetGen mesh generator
Fig. 3 - Example of intersection not allowed in the TetGen mesh generator
Fig. 4 illustrates a good example of no holes and no intersection/overlapping. The example is imported from GOCAD.
Fig. 4 - Geometries with no holes and no intersection/overlapping
You can find more information about the issue in our FEFLOW 7.5 documentation
FURTHER INFORMATION & USEFUL LINKS
FEFLOW 7.5 documentation