[rendek]

I'm trying to render some interior shots of a two story space. There is a ton of glazing and some reflections. I use AGS wherever I can and I have some simple interior lights too as well as the Physical Sky. The images are very grainy after SL17 and lots of hours.

Scene Pack & Go: http://homepage.mac.com/adamrendek/Scene.zip

[marked001]

what is the 'white' material?

[Bubbaloo]

Without looking at your material settings yet, I can suggest moving the sun to get as much direct light in there as possible. The enemy of Maxwell is indirect light or not enough light. Also, what resolution are you rendering at? Render as high res as your RAM can handle, that way the noise:pixel ratio is smaller.

[Bubbaloo]

Ok, I looked at your scene and WOW, that's a lot of geometry. I would hide as much as you can per render. There's a lot of interior spaces in the scene that are being calculated instead of the focus of your scene.

[KurtS]

optimize your materials!

1) You have many materials where the reflectance 0 layer is bright white. Change this to maximum 240,240,240
2) Don't use additive mode for normal materials (only AGS and other special materials). You have a LOT of materials in additive mode. For materials with only one layer this does not matter.
3) Make sure that you use emitter materials only on very simple geometry, or on objects with few polygons.

These three tips might not speed up the rendering, but it will clear up the scene at a lower S/L.

[Boris Ulzibat]

Merge emitters of same brightness into one single object. Then multiply the emitter material strength by the number of merged lights. (in case you use absolute settings such as Watts). This helps a lot if the lights are numerous.

[rendek]

THANK YOU very much guys!



These comments were very helpful! I'll make some adjustments accordingly and post the results here.

marked001: which white material do you mean?

Bubbaloo: ArchiCAD "spits" out a lot of geometry indeed, so I need to be much more careful with that.

KurtS: I'll go through my materials and make adjustment carefully. I wonder if the ArchiCAD add-on creates those materials in additive mode by default, since the majority of those are just auto-converted. I do have an issue with the number of materials automatically created too. I don't really know how to get around it right now.

Boris: Thank you, I tried to be very concious about my emitters, I'll look at them again.

[marked001]

I was referring to what KurtS mentioned..

[rendek]

So I optimized the scene and I'm rendering it again right now. I cut off most of the geometry and only kept the needed parts. I cleaned up the materials and optimized them (I only have a handful of them now!). I set the resolution much higher which seems to help in getting a crisper image(Bubbaloo's idea). I'll post the result soon.

The benchmark seems to be the same though as before. Is that normal? Shouldn't a higher benchmark be an indication of a more optimized scene?

[rendek]

I also tried to save the Physical Sky into an HDR and render with that, but it does not seem to affect the benchmark either. Am I doing something wrong?

[KurtS]

So I optimized the scene and I'm rendering it again right now. I cut off most of the geometry and only kept the needed parts. I cleaned up the materials and optimized them (I only have a handful of them now!). I set the resolution much higher which seems to help in getting a crisper image(Bubbaloo's idea). I'll post the result soon.

The benchmark seems to be the same though as before. Is that normal? Shouldn't a higher benchmark be an indication of a more optimized scene?

the benchmark might be the same, but that does not matter. Important is that you now get a clean rendering at a lower S/L - that's the real time-saver.

[rendek]

WOW. So the original image was rendered at 1200x675 because I was thinking that lower resolution can be rendered faster. This one (the original) I rendered at 8000x6000 and it is much better.

I think the original reached SL 17 while still remaining very grainy. This reached SL 9.30 in 16:27 hours. Much crisper, but still grainy.

What else do you guys think I could do? There is a terrazzo floor map that should be visible on a cleaner image.

Any recommendations?

Optimized Scene file: http://homepage.mac.com/adamrendek/Scene1.zip

[Thomas An.]

What happens if you disable reflective caustics ? Is the render affected by much in speed/quality ?

[Mihai]

You can make the Terrazo material a bit more efficient by not setting the weight on both BSDFs to 100 in additive mode. Change the ND of the reflective one from 1 to 3 or more and set it's weight to about 20.

[rendek]

Thanks for the answers Thomas and Mihai. I tried both ideas and they did not seem to have a significant contributions to betterment. It looks like the geometry optimazion was the most important change adn I cannot really take it further unless you guys have some additional tips. I'll have to re-render the scene with altered design so I'll post the results here soon.