Standard geometric model of spiral galaxies adopted in our models. The old stellar population consists of a disc and bulge component. The young stellar population is assumed to be restricted to the disc and consists of a non-ionising subpopulation with an age around 100 Myr, and an ionising subpopulation of stars with an age of 10 Myr. The young non-ionising population resides in a thinner disc compared to the old stars, and the young ionising population is even more compacted to the mid-plane of the galaxy. The dust distribution exhibits the same vertical extent as the young non-ionising stellar population.