Towards a 3D view on star formation regulation in nearby and high-z discs

Star formation (SF) regulation is key to understand galaxy formation and evolution. A few studies concluded that disc instability (DI) takes over stellar feedback as the main driver of SF in extremely low and high density regimes. This was based on observations of high turbulence at high z and breakdowns in SF laws, and corroborated by the increasing number of unstable discs found at high z. However, these studies neglected key properties of discs: their thickness and flaring. I present recent works improving on this. 1st, the lower break in SF laws is due to the projection effects caused by the flaring on the observed surface densities. Using a sample of well-resolved nearby dwarfs and spirals, a very tight and unbroken volumetric SF law emerges by removing the project effects. 2nd, turbulence dissipation slows down with increasing disc thickness. Using a sample of spatially-resolved star-forming discs up to z=5, we find that feedback sustains the cold gas turbulence with few percent of the supernova energy. 3rd, a thick disc is more stable than a thin disc. In our sample, about half of the high z discs are locally unstable vs none at z=0, but the unstable regions contain a small gas fraction and do not coincide with the peaks of SF and turbulence. These results suggest that SF self-regulates via feedback, while DI is secondary at most. Lastly, I present ALMA and MeerKAT surveys that will get high-resolution data for high-z and extreme systems, pushing our studies further.