Selecting an optimized, geometrically diverse subset of clips for a design layout for a semiconductor wafer is described. A complete representation of the design layout is received. A set of representative clips of the design layout is determined such that individual representative clips comprise different combinations of one or more unique patterns of the design layout. A subset of the representative clips is selected based on the one or more unique patterns. The subset of the representative clips is configured to include: (1) each geometrically unique pattern in a minimum number of representative clips; or (2) as many geometrically unique patterns of the design layout as possible in a maximum number of representative clips. The subset of representative clips is provided as training data for training an optical proximity correction or source mask optimization semiconductor process machine learning model, for example.