New seismic processing and interpretation developments will be aimed at tackling exploration issues which will require a full three-dimensional modeling of the earth. We have developed 3-D ray-tracing schemes to be used as the modeling kernel for macro-model estimation algorithms. The ray-tracing schemes are especially designed to compute rays and traveltimes through complex triangulated surfaces. The ray-tracing algorithms take full advantage of the discretization of the surfaces via triangles. An original bending technique, based on a quadratic approximation of the traveltimes, offers an adequate trade-off between the efficiency of the ray-tracer and the accuracy of the traveltimes.