The geometry checker system allows for interactively examining and testing meshes and poly objects for possible errors such as flipped faces, etc., and visualizing the results in the viewport. When the system is turned on it will perform a user supplied test on the current selection of objects and show the results of the test in the current viewport.
The IGeometryChecker interface is the base class for different geometry checkers. Geometry checkers need to register with the IGeometyCheckerManager object which provides the underlying functionality for activating tests and managing the display and output of test results.
The geometry checkers source code is released as a sample in the folder maxsdk\\samples\\GUP\\GeometryChecker.