hpp-fcl is a modified version the FCL libraries.
It is a library for collision detection and distance computation between various types of geometric shapes reprensented either by
The main entry points to the library are functions
detection and distance lower bound
Collision queries can return a distance lower bound between the two objects, which is computationally cheaper than computing the real distance. The following figure shows the returned result in CollisionResult::distance_lower_bound and DistanceResult::min_distance, with respect to the objects real distance.