Matthew W. Lewis Richard E. Parent Interactively Evolving Virtual Environment Maps with Continuous Layered Pattern Functions. 49-54 2002 conf/ca/2002 CA https://doi.org/10.1109/CA.2002.1017506 https://doi.ieeecomputersociety.org/10.1109/CA.2002.1017506 db/conf/ca/ca2002.html#LewisP02