SUN light kills samples for interior scene Tweet

[3dreamstudios]

Wasn't sure how to word the title... So I have an interior scene that has say 50 lights, it's a large hotel conference hall. One side has large windows I want light to spill in.

Without the exterior SUN light having any samples my lighting cleans up pretty quickly, within 1500 samples or so. With the exterior light on FULL BLAST (about 60,000 brightness) the samples inside do not clean up nearly as quickly. If I turn the brightness down, the SUN doesn't fill the room but the quality does reach it's normal level much quicker.

So it seems that the brighter I make the SUN light outside the slower it is for the inside to clean up. I did find that I can make the SUN light have .1 samples and I get the affect I want, making the floor have the window light shadows and the quality cleans up much quicker.

Just wondering why so I can understand a bit more about this setup. Thanks for any thoughts.

PS: I'm using Direct Lighting, Ambient Occlusion. I do not have the time to use Diffuse or PMC.

[Builtdown]

Add exposure in Imager node.

[3dreamstudios]

Add exposure in Imager node.

Yea it's not that it needs exposure, not looking to brighten things up with the sun...I'm not getting any bounced light using Kernel I'm using...just looking for that sun to brighten the floor without causing the rest to clean up slowly. Which I figured out but making the .1 sample rate on the sun. Just curious why this setup causes so much slow down because of how bright the sun is.

[baltort]

Is this a job for a portal node?: https://docs.otoy.com/StandaloneH/Stand ... ght=portal

It sounds like you have a very bright light dominating your scene and you're only using the bit of it that makes it through the windows to illuminate your scene. I haven't experimented with it, but I think that's what the portal material is for....

Cheers,

James.

[3dreamstudios]

Is this a job for a portal node?: https://docs.otoy.com/StandaloneH/Stand ... ght=portal

It sounds like you have a very bright light dominating your scene and you're only using the bit of it that makes it through the windows to illuminate your scene. I haven't experimented with it, but I think that's what the portal material is for....

Cheers,

James.

I agree I thought that would fix it..but I was not impressed by it's ability to help the situation. I may have been doing something wrong, not sure. I might revisit it. But I think your dead on...the light (very bright) emmitted from the SUN light is hitting lot's of other things outside, trees etc... and needing samples...the inside is now "shadowed" by the geometry surrounding it...thus the interior lights need to fill in. With PMC or other kernel I see where that would matter...but I would hope that if a RAY doesn't hit or bounce on the inside it wouldn't affect anything, time or other.

[baltort]

What are you using for your sun? If you're using an actual octane light, then maybe try switching to an environment image? It might not get the shadows quite as hard, but I suspect it will be much more efficient to render.

[3dreamstudios]

What are you using for your sun? If you're using an actual octane light, then maybe try switching to an environment image? It might not get the shadows quite as hard, but I suspect it will be much more efficient to render.

Yea good idea, I'll look through my HDR's to see if I can get something sharper...there is importance sampling on that module.

My problem ususally when trying to use Direct Lighting and Ambient Occlusion is that I can't control my lighting as well. Was super happy to have an environment and a VISUAL environment. I'll see if I can combine them and make something work. Good idea.

[Draydin_r]

If your looking at hdr and require some flexibility in adjusting sunlight I would highly recommend purchasing hdrstudio. It integrates perfectly with lightwave and octane and you can tailor light sharpness, color and brightness however you like, even with existing hdr maps.

Draydin_r

[LightwaveGuru]

PS: I'm using Direct Lighting, Ambient Occlusion. I do not have the time to use Diffuse or PMC.

Wrong Kernel. For that you have to use the Path Tracing Kernel. The Direct Lighting Kernel (with amb occ) can not Trace what you want...it have a reason that the name is DIRECT Lightning...so the DL KLernel is better for outside environment scenes...
if you need full tracing for all lights you need the PT or PMC-Kernel...

snip lwguru

[3dreamstudios]

PS: I'm using Direct Lighting, Ambient Occlusion. I do not have the time to use Diffuse or PMC.

Wrong Kernel. For that you have to use the Path Tracing Kernel. The Direct Lighting Kernel (with amb occ) can not Trace what you want...it have a reason that the name is DIRECT Lightning...so the DL KLernel is better for outside environment scenes...
if you need full tracing for all lights you need the PT or PMC-Kernel...

snip lwguru

Fully aware if I wanted bounced light I would need different kernel. I was just wondering why even with direct lighting (no bounce) such a setup would make the samples quality solution go way down in time. Just so I can understand what's going on under the hood so to speak. Makes no sense to me...

If there are not bounced rays, with DL in this situation, would I not get the rays coming through the window and only the rays inside (which solve quite quickly). Why is it that with a very bright light outside it reduces the quality solving timeline quite a bit?