What is the Adaptive light solver (New light solver) option?



What is it?


The Adaptive light solver option (formerly known as New light solver) found under Render Setup > Performance toggles the new improved 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, especially 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)


Note: it may sometimes appear that the adaptive light solver produces brighter images, however:

  • The difference in brightness should disappear after longer render time (the image with the adaptive solver enabled will simply converge to the correct result faster than the one with the adaptive solver disabled).
  • The results produced with the adaptive solver enabled are always less biased (more realistic) than with the adaptive solver disabled.




How to use it?


If the Adaptive light solver checkbox is not enabled in your scene under Render Setup > Performance, just enable it and render your image. The Adaptive light solver does not have any additional switches or settings.


Corona Renderer 4:





Corona Renderer 3 and older:





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: the New light solver (renamed to Adaptive light solver) is enabled by default for all new scenes.

    Note: the state of the Adaptive light solver checkbox is saved in the scene, so if an older scene with the Adaptive light solver disabled is opened in a newer version of Corona Renderer, the Adaptive light solver will remain disabled to guarantee consistency with older renders.





Examples


1. Abstract scene with multiple light sources occluded by geometry

Render time 1 minute.


Click HERE to enlarge




2. Exterior scene with clay material applied to show differences in noise level.

Render time 5 minutes.


Click HERE to enlarge



3. Interior scene with clay material applied to show differences in noise level.

Render time 5 minutes.


Click HERE to enlarge