Using multi-band photometry we train a forward model to emulate the colour-change due to temperature and extinction for stars. We simultaneously solve for the astrophysical parameters (APs) extinction A0, temperature Teff and distance modulus μr in a Bayesian framework for individual stars. We introduce an HRD prior to account for previous knowledge about the distribution of stars in the temperature- absolute magnitude plane (see also Bailer-Jones 2011). This allows us to infer distance information. We obtain the full three dimensional PDFs of all the stars in a field, allowing us to determine extinction-distance profiles for a given line of sight.