importance_light VEX function

Returns an estimate of a light’s contribution to the overall scene lighting.

Contexts: displace, fog, light, shadow, surface

See also: getlights

  1. float importance_light(int lightid)

You can compare the value returned by this function with the “importance” returned for other lights to determine which lights need more sampling.

lightid is an integer identifying a light. You can get a list of light IDs for lights affecting the currently shaded surface with getlights.