The implementation of Generalized ICP does not use the DefaultConvergenceCriteria::Ptr convergence_criteria_ This causes confusion when trying to check the state of convergence after running the alignment. Checking the hasConverged() method will return true but checking the state through getConvergenceState() will return ConvergenceState::CONVERGENCE_CRITERIA_NOT_CONVERGED. Because of the conflicting states, it is difficult understand what the state of the convergence is.

A similar issue was brought up for ICP in issue #1598 and addressed by @WraithKim in PR #2892.

Possible Solution

If the using the DefaultConvergenceCriteria does not apply to GICP, the implementation should override getConvergenceCriteria() to throw an exception in order to avoid confusion. Otherwise, the convergence_criteria_ should be updated with the appropriate convergence conditions.