Warnock algorithm [SEP] discoverer or inventor
Warnock algorithm
The Warnock algorithm is a hidden surface algorithm invented by John Warnock that is typically used in the field of computer graphics. 
It solves the problem of rendering a complicated image by recursive subdivision of a scene until areas are obtained that are trivial to compute. In other words, if the scene is simple enough to compute efficiently then it is rendered; otherwise it is divided into smaller parts which are likewise tested for simplicity.
This is a divide and conquer algorithm with run-time of formula_1, where
Robert Tarjan
Robert Endre Tarjan (born April 30, 1948) is an American computer scientist and mathematician. He is the discoverer of several graph algorithms, including Tarjan's off-line lowest common ancestors algorithm, and co-inventor of both splay trees and Fibonacci heaps. Tarjan is currently the James S. McDonnell Distinguished University Professor of Computer Science at Princeton University, and the Chief Scientist at Intertrust Technologies Corporation.
Early life and education.
He was born in Pomona, California. His father was a child psychiatrist