One light, one camera, one box - hours to render

[NHHiker]

I have an extremely simple scene consisting of a single skydome light, a physical camera and a box object with a small bitmap texture. In trying to render out 200 frames of this at 1920x1080, it takes 3-4 hours. I'm obviously missing something REALLY basic. At first, I thought it was because I had no lights in the scene at all. Then, no cameras. But adding both of these items has done nothing to change the estimated completion time. 

Can anyone tell me what's going on?
Thanks much. 
John

[wernienst]

Hmm. Using your test scene with my modest system, I get 25s per frame which would sum up to about 1h 25m in total.

According to these benchmarks (from cpu-monkey.com), your results look reasonable.

Have you checked Task Manager, if other programs are claiming CPU time/RAM?

You could also try Arnold's GPU mode. In this case (Camera (AA) Samples = 5) I get 6s per frame or about 25min in total on my system (Geforce RTX 2070).

[MartinBeh · Accepted solution]

I am sure I am missing something here, so please help me understand this better:

- What is the overall result you are trying to achieve? 

- Why is there a skylight for a single, textured box?

- Why render frames 200-400 if there is no animation at all?

- Why do you need 5 AA-Samples?

- if all you need is to render the textured box, why use Arnold as renderer, and not Scanline, for example?

On a completely outdated laptop, using your scene one frame took 09:44 min to render without changing any settings. That is really slow.

But just changing the sampling from 3/2/2/2/2/2 to 1/1/1/1/2/2 (and disabling the Denoiser) brought this down to 00:27 min with barely any visible difference (which would go away completely if Denoiser is kept active). Also I recommend not to directly render to AVI.

[NHHiker]

So to answer some questions: I no longer use Max very much. I primarily use ACAD, but need to do animations a couple of times a year. I have always used the scanline renderer because it's always worked. I was under the impression that Arnold was a 'faster and better' renderer, and I thought that it was eventually going to phase out scanline. Therefore, I was trying to create new projects under Arnold. But I don't think it is best for what I personally do as I don't have the need to create complex textures or use advanced lighting. 

At this point, it's easy and fast enough for me to convert this project over to scanline render it. 

Addressing other questions: The full project is an animation (thus the 200-frame render), but most of the elements were stripped out while testing what might have been slowing things down. My Camera (AA) setting is 2. It's never been set at 5. Perhaps that is something your system is set at? In fact, I do have all of my sampling set as you suggested. For larger jobs, I wouldn't render directly to AVI, but for this simple project, it's not a problem. 

Thanks VERY MUCH for confirming that it wasn't just me. It amazes me that Arnold takes SO long to render the most basic of scenes. 

[MartinBeh]

Sorry about the AA=5 confusion, I mixed up what you have in the scene (AA=2) and what @wernienst has tried.

I did set it down to 1 (along with the other sampling rates) and Arnold rendering went down from roughly 9 min to 30 seconds, so it can render fast, too. And if you use Denoiser (which is active by default now), AA=1 might be fine.

And yes, Scanline is very old and it will likely not support advanced rendering tools to be developed in the future, but for now it should do this job quite nicely. And by the way so should Quicksilver, if you like to use your GPU more.

[NHHiker]

Thanks again. Can you tell me how to deactivate the Denoiser? Under the Render Setup/Denoiser tab, "Output Denoising AOVs" is not checked and there doesn't seem to be any other checkbox to turn it off. 

I'll look into Quicksilver when I get some down time. 

[MartinBeh]

Arnold has multiple ways of denoising - the one I am referring to can be found in the Render settings > Arnold Renderer tab > Imagers rollout (at the very bottom, see here).

For still images, these denoisers normally are a great way of reducing AA samples (= cutting down render time) while keeping visual quality, but for some simple cases (such as your test scene) they might just add more overhead than time saved. Also for animation, they might introduce their own set of artifacts, as many of them do not take any temporal continuity into account. So you will have to experiment a bit; I suggest you set the camera samples really low when you turn on Denoiser, to see what it does and whether you like the results.

[MartinBeh]

PS: 9 seconds for Scanline on the same old laptop; 7 seconds for Quicksilver (without any real GPU available).

[NHHiker]

Awesome info. Thanks again!