LuxCoreRender Forums

If I have about 12 small lights as shown in the attached image that doesn’t really contribute much to the scenes lighting, and then just have a SUN and SKY setup, how should the IMPORTANCE bet set? Should it be something like ‘1’ for each of the small lights and then about ‘13’ for the SUN? And should PGI Cache be 'ON' for Emitter Planes?

EDITED: This will be for an animation.

Many thanks

Very good question. i think importance should be internally ruled by the engine. but wait dade or BYOB for that.

Maybe it helps to read the "Light strategy" section here: https://wiki.luxcorerender.org/Render_Configuration
With the default "log power" light strategy, it should not be necessary to tweak individual light importance. However you can just try it and compare the results, if a light is not sampled enough it will appear noisy. You can also put your weak lights into an extra light group to check their noise level separately.

Post
by B.Y.O.B. » Tue Sep 03, 2019 12:52 pm

…... if a light is not sampled enough it will appear noisy. You can also put your weak lights into an extra light group to check their noise level separately

I've been struggling to get rid of the noise that's in the glass panel in front of the LED lights, so thank you for the help and I'll definitely try your suggestion to 'put your weak lights into an extra light group to check their noise level'.

How do I actually test the noise percentage in a light group once the light group has been set up, or is it just a visual test?

Thanks again

Racleborg wrote: Tue Sep 03, 2019 11:13 am If I have about 12 small lights as shown in the attached image that doesn’t really contribute much to the scenes lighting, and then just have a SUN and SKY setup, how should the IMPORTANCE bet set? Should it be something like ‘1’ for each of the small lights and then about ‘13’ for the SUN? And should PGI Cache be 'ON' for Emitter Planes?

Try to disable "Direct Light Sampling" for all led lights or use DLSC cache, they should both reduce a lot of noise.

Racleborg wrote: Tue Sep 03, 2019 12:06 pm How do I actually test the noise percentage in a light group once the light group has been set up, or is it just a visual test?

Just flip between them. Yes, it's just a visual test.

Many thanks

Try to disable "Direct Light Sampling" for all led lights or use DLSC cache, they should both reduce a lot of noise.

Many thanks. I'll try that.