With the more than 4000 exoplanet discoveries to date, theoreticians have even more challenges to explain how this diverse population of planets came to be. While we have an understanding on the major steps of the planet formation process, the details are less clear, and we fail to reproduce even our Solar System. We use more and more physically complex computer simulations to address the challenges of planet formation. The previously omitted physical effects, such as thermodynamics, led to quite surprising new results. In my talk I will present 3D thermo-hydrodynamical simulations with mesh refinement, and discuss how thermodynamics, and other mechanisms challenge and perhaps change the traditional planet formation models. I will also quickly review what these simulations are predicting on how to observe forming planets, and what information we can & cannot gain from such observations.