During their positioning, the geomembranes employed for water retention ponds and in other applications are usually damaged. The methods generally used to quantify these damages are punctual. Using a direct contactless and full view technique to measure the damage could permit the classification of this damage with objective indicators. The technique of structured light was used to measure the shape of geomembranes. This technique consists on the projection of a grating on an object and on the observation with a camera. The positioning of the resulting fringes is characteristic of the shape of the object so it is possible to measure the 3D shape of an object with this technique. After a presentation of the theory of the method, its application for the measurement of geomembranes shape is presented.