Some of the highlights:
- GPU Denoising gives near instant denoising when using IR (and can be also used for non-interactive rendering).
- CoronaMultiMap and CoronaUvwRandomizer feature a new randomization by Mesh Element mode.
- Improved IR performance keeps everything smooth and snappy.
- Displacement improvements allow you to use lower Displacement settings with the same image quality, lowering memory usage by up to 50%.
- Various memory optimizations let you save up to 2.5 GB for an 8K render (or more for larger resolutions).
- A focus on fixing bugs.
More info on Corona 3 website.