Caustics are everywhere. Defined as concentrations of light refracted or reflected off a specular surface, common examples include the patterns you see on the bottom of a pool and the bright curves of light in a wine glass's shadow. But they also affect the way you see through windows and the reflections cast by any shiny surface. Turning on caustics in ray traced renders can add subtle levels of realism, but their high computational expense means they are usually omitted.

That is until now. The latest release of the Corona Renderer includes a vastly improved caustics solver — which minimizes resource-intensive overheads. In this podcast, Corona's Founding Partner and Main Developer Ondřej Karlik, and R&D Partner Jaroslav Křivánek tell Chris why caustics are so hard to compute. They also discuss the approach they took to make them work, their vision for the future of caustics — and whether the new solver will make its way to V-Ray.