I made a jsfiddle and added dat.gui http://workshop.chromeexperiments.com/examples/gui/#1--Basic... so you can modify the "detail" parameter to change the terrain without requiring a page refresh http://jsfiddle.net/kachhalimbu/br8Xd/1/
Full screen result here http://jsfiddle.net/kachhalimbu/br8Xd/1/embedded/result/