What is the new "New light solver" option?



What is it?


The New light solver (experimental) option found under Render Setup > Performance toggles new experimental method of rendering lights introduced in Corona Renderer 1.7.
This optional new algorithm can speed up your renders by up to 6 times by learning which scene lights are important at a particular location. Those lights then receive more rays than the others, resulting in a lower noise level.


Enabling this option may significantly reduce render times in scenes:

  • With many lights (e.g. 10 or more)
  • Where lights have complex shapes
  • With complex lighting scenarios (e.g. if the lights are occluded by some objects, blocking the path from the light source to the camera)




Is it on or off by default?


In Corona Renderer 2 and older: the new light solver was still a work in progress. Generally it worked well, but disabling it by default was a safety measure we decided to include in the 1.7 release. 

In Corona Renderer 3 and newer: the new light solver was refined and should not cause issues in any scenarios, but we still decided to make it off by default as a safety measure. 

In Corona Renderer 4 and newer: we are planning to make the new light solver on by default. 




How to use it?


If the new light solver is not already enabled in Render Setup > Performance, just enable it and render your image. 




Examples


New light solver option disabled:



New light solver option enabled: