Surface analysis - Islamic Art Museum in the Louvre, Paris (Bellini Architects). Top: A quad-dominant mesh which follows a so-called network of conjugate curves can be made such that faces are planar. Unfortunately this surface geometry does not leave us sufficient degrees of freedom to achieve a satisfactory quad mesh . Bottom: Hybrid tri/quad mesh solutions with planar faces posses more degrees of freedom (images courtesy A. Schiftner). The one at bottom right has been realized.