1. A method of generating a geologic model, comprising the steps of: (a) assigning a rock-property value to each block of a candidate geologic model; (b) assigning a local spectrum of said rock property to each of said blocks, each said local spectrum incorporating a local spatial trend in rock property continuity; (c) using said local spectra to frequency scale said rock-property value at each of said blocks, (d) using said scaled rock-property values to generate a scaled geologic model incorporating said local spatial trend in rock property continuity.