Gilbert–Johnson–Keerthi distance algorithm

The Gilbert–Johnson–Keerthi distance <a href="/facts/Algorithm/fnl5NmRt">algorithm</a> is a method of determining the minimum distance between two <a href="/facts/Convex_set/vdAuJRJl">convex sets</a>, first published by <a href="/facts/Elmer_G._Gilbert/rGAUzD97">Elmer G. Gilbert</a>, Daniel W. Johnson, and S. Sathiya Keerthi in 1988. Unlike many other distance algorithms, it does not require that the geometry data be stored in any specific format, but instead relies solely on a <a href="/facts/Support_function/W1k6H5lL">support function</a> to iteratively generate closer <a href="/facts/Simplex/0FCfNRN8">simplices</a> to the correct answer using the configuration space obstacle (CSO) of two convex shapes, more commonly known as the <a href="/facts/Minkowski_difference/dEQfoJ1A">Minkowski difference</a>.
"Enhanced GJK" algorithms use edge information to speed up the algorithm by following edges when looking for the next simplex. This improves performance substantially for polytopes with large numbers of vertices.
GJK makes use of Johnson's distance sub algorithm, which computes in the general case the point of a tetrahedron closest to the origin, but is known to suffer from numerical robustness problems. In 2017 Montanari, Petrinic, and Barbieri proposed a new sub algorithm based on signed volumes which avoid the multiplication of potentially small quantities and achieved a speedup of 15% to 30%.
GJK algorithms are often used incrementally in simulation systems and video games. In this mode, the final simplex from a previous solution is used as the initial guess in the next iteration, or "frame". If the positions in the new frame are close to those in the old frame, the algorithm will converge in one or two iterations. This yields collision detection systems which operate in near-constant time.
The algorithm's stability, speed, and small storage footprint make it popular for realtime <a href="/facts/Collision_detection/kXkE9WXv">collision detection</a>, especially in <a href="/facts/Physics_engine/lAsEdSA4">physics engines</a> for <a href="/facts/Video_games/vmTdNASJ">video games</a>.

Gilbert–Johnson–Keerthi distance algorithm open-in-new

Gilbert–Johnson–Keerthi distance algorithm