Twilight Render User Forum

Another of my possibly disturbing renders.... Don't take a seat. Rendered just using Sun-Sky with sky portal over the windows. First image rendered Easy 10 (not sure why Easy 9 wasn't giving good results in early testing ). Second image was an experiment with "volumetrics". Rendered scene on med setting, took almost as long as the Easy 10 render. Blended the two renders together in Gimp. It was an interesting experiment.

Rendered scene on med setting, took almost as long as the Easy 10 render.

Sky portal slows down greatly the Easy 1-7 render settings.

Why? If Easy 4 calls for 10000 rays per light, and the sun is a light and the sky is a light, then 10000 rays will be shot from each light source=20000 rays. These are 20000 random rays - so only a few will fall through the windows into the space. Let's guess for argument sake that maybe 300 rays per light source outside of the windows will make it into the space through the windows.
So it will only be calculating bounces from 600 light rays.
Now if you put sky portal - all 10000 rays from each light source will be entering the space. So now it is calculating 20000 light rays instead of 600.
So you can use even lower ray settings when using Light Portals, or just hide the light portals when rendering on Easy 1-7, as they make rendering longer.

Render is sped up with Easy 9 and 10 with light portals because with those settings - the more direct light, the better.

As always Fletch. thanks for the great info. Was clueless about how sky portals affect the biased render settings. Would have been better to not have used them I suppose.

No problem, Tuna.

I have sent you a Private Message.

Somehow, I've never managed to do volumetric. I've even followed the tutorial on YT, but it wont work.

Please share your scene here, and we will take a look and advise.

Nvm Fletch, I managed to get it to work, but the only problem is that it only works with biased methods. I would love for it to work with unbiased methods.