3D MHD models angular quadratures

There are two requirements for an optimal quadrature that are difficult to satisfy simultaneously: high accuracy and short computing time. Recently, imposing certain symmetries, we have derived a set of near optimal angular quadratures.

Here we extend our previous investigation by considering other symmetries. Moreover, we test the performance of our new quadratures by numerically solving a radiative transfer problem of resonance line polarisation in a 3D model of the solar atmosphere resulting from a magneto-hydrodynamical simulation. The new angular quadratures derived here outperform the previous ones in terms of the number of rays needed to achieve any given accuracy.