Behind the scenes, we've been redesigning LightUp to leverage GPU raytracing which can hugely increase lighting speeds. LightUp uses a proprietary GPU raytracing system that performs raytracing using any modern GPU - not just high end RTX GPUs! LightUp schedules packets of lighting work for your GPU which it can chew through in parallel while moving around your model with TourTool.
This release completes an important step in this journey with the introduction of 'temporal progressive lighting'. Yes, its a mouthful! It means that LightUp schedules packets of lighting work that run across many frames so you can see the lighting converge on the solution as you move around. If you change settings or move lights, it is instantly noticed and new packets of lighting work generated.