We present in this paper the numerical computation of the multi-valued travel-time field generated by a point source experiment in the Marmousi model. Two recently developed methods are combined to achieve this goal : a method called big ray tracing, used for the computation of multi-valued travel-time fields, and an eikonal solver designed to work on unstructured meshes.\\ Big ray tracing is based on a combination of ray tracing and local solutions of the eikonal equation. A classical ray tracing first 'discretizes' the phase space and defines local zones which possibly overlap where the travel-time field is multi-valued. An eikonal solver then computes the travel-time in these zones called big rays. It acts as an exact interpolator between rays associated to different branches of the travel-time field. The geometry of the big rays may be complicated and is best discretized using unstructured meshes. An eikonal solver designed to work on unstructured meshes is used.