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View Full Version : Speeding up a scene with a LOT of volumetric lights...



starbase1
03-17-2019, 12:52 PM
Hello All,
I'm working on a scene for a Lunar orbital outpost, and the customer wants lots of atmospheric volumetric lights.
(LW 11.6)

I'm going for sprite quality lights, (not too awful so far)
2/4 adaptive AA
No global illumination
1 shading sample, 1 light sample
Polygon count is about 600k


The render times are getting painful, and the image quality is not good enough either... Sample still attached144497

Is it just a case of being patient?

I have a suspicion that the overlapping of some of those volumetric lights is a big part of the problem, but trying to find an arrangement that minimises that won't be easy.

Any suggestions for things to try?

RebelHill
03-17-2019, 01:33 PM
Your customer does realise there's no volumetric medium in space, right?

Anyhow, cant think of a great deal you can do... if the speed hit is coming from having the vol lights in the scene (and the speed is ok without), then only thing I can suggest is to use geo cones instead, with graduated transparency and luminosity based on incidence to view. For shots such as you show, that can work out ok... it only turns to useless if your camera has to pass through/inside the volume.

starbase1
03-17-2019, 02:01 PM
He's ex NASA, he realises! But he also used to be in the Navy, and likes the way it looks like night on a boat...

I'll have a think about your approach, thank you.

prometheus
03-17-2019, 02:14 PM
Your customer does realise there's no volumetric medium in space, right?

Anyhow, cant think of a great deal you can do... if the speed hit is coming from having the vol lights in the scene (and the speed is ok without), then only thing I can suggest is to use geo cones instead, with graduated transparency and luminosity based on incidence to view. For shots such as you show, that can work out ok... it only turns to useless if your camera has to pass through/inside the volume.

There´s tons of volumetric medium in space, gases nebulas etc...If you look at the big picture:D

prometheus
03-17-2019, 02:21 PM
Any suggestions for things to try?

Go for lowest acceptable quality in the volumetric light.

go to Effects/volumetrics tab, turn off volumetric Antialiasing.
Turn off opacity casts shadows.

Get a better pc.

RebelHill
03-17-2019, 02:31 PM
boat

ship.