  For more than twenty years, Ray Tracing methods have continued to improve on
both accuracy and computational time aspects. However, most state-of-the-art
image-based ray tracers still rely on a description of the environment that
only contains planar surfaces. They are also limited by the number of
diffractions they can simulate. We present Min-Path-Tracing (MPT), an
alternative to the image method that can handle diffractions seamlessly, while
also leveraging the possibility to use different geometries for surfaces or
edges, such as parabolic mirrors. MPT uses implicit representations of objects
to write the path finding challenge as a minimization problem. We further show
that multiple diffractions can be important in some situations, which MPT is
capable to simulate without increasing neither the computational nor the
implementation complexity.
