What is the Adaptive light solver option - 3ds Max? – Chaos Help Center

What is it?

The Adaptive light solver option (formerly known as New light solver) found under Render Setup > Performance > Development/Experimental Staff > Lights toggles the new improved method of rendering lights and starting from Corona 4 this option is ON by default.

This 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.

This option significantly reduces render time, 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 a 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 enabled by default and can be found under Render Setup > Performance > Development/Experimental Staff > Lights.

Check this article for How to enable the "Development / Experimental stuff" rollout in Corona for 3ds Max?

Is it on or off by default?

Starting from Corona 4 the 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.