This paper proposes a new method of surface shape determination for transparent objects. Concretely it deals with a detection of glass-sheet corrugation nearby the sheet edge. This variable is important for cutting distance optimization. Time-dependant laser reflection was used to generate a surface profile. Projection dependence was set. That allows calculating a distance of deformed part. Results were compared with another innovative method, confocal sensor distance measurement and with zebra test, optical test widely used in glass industry.