The crash happens in specific cases when doing euclidean resection
in cases when first 3 3D estimates are correlated. While it is a bit
cryptic on user level, what it could mean is:
- Either there are overlapping markers
- Or the optical system is highly out of calibration.
Either of these cases is not the primary goal to support with camera
solvers in Libmv for the time being, so while this change avoids the
crash there is possibility to make algorithm more robustly handle the
tracking data and potentially give better result.
Such correlation via some intermediate steps leads to the algorithm
attempting to perform SVD decomposition of a matrix with NaN values
in it.
The exact reason of the crash is not super clear as it happens deep
in the JacobiSVD decomposition code in Eigen and caused by invalid
index somewhere. It might be a bug in Eigen which doesn't do range
checking, hoping that the math does not fail in cases like NaN and
inf.
Pull Request: https://projects.blender.org/blender/blender/pulls/145301
1d88e19c32