Noisy Images - multiple light sources.

[Satchem]

Hi Guys,

I work as a designer and engineer and I use Thea to render designs of events and installations I make for clients. Some of the renders I produce are embarrassingly noisy and I've tried many ways to make this better, with still limited luck.

Attached are two images that show the kind of thing I'm attempting to do.

The first is a tunnel that came out quite nice and crisp: 600+ light sources.

The second is a sample scene for a bigger project, the renders for which never became sharp and always had a terrible noise to them.

Any pointers or ideas on where I'm going wrong or how I can improve this? Open to any suggestions.


Thanks

[JQL]

In the second image it seems the soft radius of your light is intersecting other geometry. Soft radius defines something like the size of the lightbulb and though you don't see it, it shouldn't intersect other geometry. That noise is the typical effect that happens when it does intersect.

[Satchem]

Thanks,

that helped me a lot at first, but since then I have tried to avoid any interaction there. But I still get the noise.

Sometimes the gap between the emitter and another surface may only be a few millimetres, but it is a gap all the same.

Any other ideas on this? I may be making another simple mistake somewhere.

[JQL]

Do you have your lights inside glass? If so, that might be an issue too, especially if that glass is based on a glossy material as it emits caustics (not so much on thin glass).

I would advice you to use invisible mesh lights then. You set your glass to be a passive emitter and then you model a geometry around it which you set to an invisible emitter. The combination of both will give you invisible light source, with spherical geometry, and light won't have to travel through a caustics generating material which usually leads to huge render times.

[dbalex]

Can't you use optix on those scenes to clear the remaining noise?

[Rombout]

He is using 1.5 so no optix. There can be so many problems, its hard to tell looking at an image. I t can be intersecting lights, bad materials. I would rather think that first image would cause more of an issue because of the many lights and high reflective surfaces near them.

[Satchem]

Right!

I'm very careful to avoid intersections and I try and keep materials to the Thea palette and as minimal as possible. But as you can see there are lots of downloaded assets in the jungle version so that may be an issue.

Stumped, but thanks for your comments.

[Rombout]

For that jungle scene. If you got time you could always do test and see what causing it. Start the scene as plain as possible than do quick test renders adding item by item. Perhaps you can narrow down you issue or object.

[Satchem]

That's a great idea.. I'll do that when I find a moment and work back.


Thanks