Mendell's film career began in 1991 as a set model builder on the Steven Spielberg film Hook. He has since designed and built set models for such films as Death Becomes Her (working with Star Trek: The Motion Picture production illustrators Tom Cranham and Martin Kline), Jurassic Park (also working with Cranham and Kline), Mars Attacks! (featuring Paul Winfield), The Insider (starring Bruce McGill and Christopher Plummer), Three Kings, and Windtalkers (starring Christian Slater). He has also built digital models for films such as Minority Report (featuring Neal McDonough and Patrick Kilpatrick), Jurassic Park III (featuring Linda Park), and Ali (featuring LeVar Burton, Michael Dorn, Brad Greenquist, Albert Hall, Bruce McGill, William Utay, and Wade Williams).