Title: Epipolar curves on surfaces Authors: Peter J. Giblin and Richard S. Weiss Affiliation: Computer Vision Research Laboratory, Dept. of Computer Science, University of Massachusetts, Box 34610, Amherst, MA 0l003-4610 Abstract: The view lines associated with a family of profile curves of the projection of a surface onto the retina of a moving camera defines a multi-valued vector field on the surface. The integral curves of this field are called epipolar curves and together with a parametrization of the profiles provide a parametrization of regions of the surface. We present an investigation of epipolar curves on the object surface and in a related `spatio-temporal surface'. Where the epipolar plane is tangent to the surface, the epipolar curve has a cusp and the epipolar parametrization breaks down . A description is given for the geometry of all of the generic cases where the epipolar parametrization breaks down. These results give a systematic way of detecting the gaps left by reconstruction of a surface from profiles. Keywords: surface reconstruction, epipolar constraint, epipolar curve, spatio-temporal surface.