Howdy;

I have an arch-vis-like scene with lots of interior lights (well, 12 lights), each using an IES profile. It seems like the use of IES profiles adds significantly to the render time, is this true? If so, why? Is there a way to optimize this?

Spelunking the logs, there's mention that the lights aren't being added to the light tree, which seems bad, except I don't know what a "light tree" is.

dhemberg
Howdy;

I have an arch-vis-like scene with lots of interior lights (well, 12 lights), each using an IES profile. It seems like the use of IES profiles adds significantly to the render time, is this true? If so, why? Is there a way to optimize this?

Spelunking the logs, there's mention that the lights aren't being added to the light tree, which seems bad, except I don't know what a "light tree" is.

Yes. Any shader applied to the light, which includes spotlight, barndoors, and ies profiles, will exclude it from the light tree. The light tree is an acceleration structure to improve efficiency with large numbers of lights.

Fantastic, thanks for the insight!