PenetrationLocator

• A PenetrationLocator provides the perpendicular distance from a Secondary node to a Primary side and the "contact point" on the Primary side.

• The distance returned is negative if penetration hasn't yet occurred and positive if it has.

• To get a PenetrationLocator #include "PenetrationLocator.h" and call getPenetrationLocator(primary_id, secondary_id) to create the object.

• The algorithm in PenetrationLocator begins by using a NearestNodeLocator so patch_size is still important.

• After a nearest node is found, elements neighboring that node are checked to find a contact point. By default, the determination of "neighboring" relies on mesh topology and checks the elements which are directly connected to that node. For meshes in which a surface element may touch a node that is not one of its own nodes (such as Flex IGA meshes, or adaptively refined in 3D, preceding use with setUsePointLocator(true) switches to a slower but more comprehensive octree-based algorithm.

• Most user interaction with a PenetrationLocator is likely to be through objects which inherit from GeometricSearchInterface. Users can change the algorithm of PenetrationLocator by setting search_method=all_proximate_sides on such objects.