How can I improve render times over Arnold GPU?

[sean_brown]

I am trying to improve my render times and get acceptable results for animation but I haven't been able to do better than my results with Arnold and wondered if I am missing anything.
Below is a link to a video with both renders playing back to back for comparison with render stats in the on screen titles at 640x480. Take note the normal's is pointing in the wrong direction in the window frame on the left and that's why its white in Arnold. I also choose brute force for vray as light cache was causing more flickering.

V-Ray Render Settings
GPU-RTX (3090)
Brute Force 4 GI depth (Light Cache caused flickering)
5000 sample limit
.005 noise threshold
no time limit
Intel denoise

Arnold Render Settings
GPU
4AA camera samples
60 adaptive samples
Oidn2 denoise

https://drive.proton.me/urls/YX2N92EW3W#7ZMbDofTSWc5

Here are two 1080p stills from each with and without denoise.

V-Ray w/Intel Denoise rendering time 15:56



V-Ray No Denoise



Arnold Oidn2 denoise render time 11:35



Arnold No Denoise



Using light cache on the 1080p renders did come in at 8:24 but geometry wasn't as clean and flickering occurred.

The original scene is by Jeremy Vickery and Alex Mateo and is free to download here https://alexmateo.gumroad.com/l/QstPZ. I stripped all original lights and materials and used each renderers native area lights with the same size and positioning.

[stezza]

I got 4min 28 for a render that I'd say was good enough for animation I have never used anything lower than 0.08 for animation.

RTX 3060 Ti

[stezza]

3min 6 sec with physical camera!
This is a saved jpg by the way.

[vladimir_krastev]

stezza you seem to have turned off reflections which will speed up render times.
sean_brown the two images don't look the same. The one rendered with V-Ray has a lot more GI and more interesting lighting. I don't know if this is because of the lighting setups but surely can play an important role in render times. It will be interesting to see what the times will be with higher resolutions.

Using light cache on the 1080p renders did come in at 8:24 but geometry wasn't as clean and flickering occurred.

Did you use the animation preset?

It is not normal to flicker and using Lights Cache reduce render times a lot.

[sean_brown]

stezza you seem to have turned off reflections which will speed up render times.
sean_brown the two images don't look the same. The one rendered with V-Ray has a lot more GI and more interesting lighting. I don't know if this is because of the lighting setups but surely can play an important role in render times. It will be interesting to see what the times will be with higher resolutions.

Did you use the animation preset?

It is not normal to flicker and using Lights Cache reduce render times a lot.

My take on difference is the Arnold is a big more contrasty. What bothers me about the vray render is many of the shadows in the details of the furniture are lesser which loses detail in the furniture overall, like the clock looking book case in the left corner, the details at the top.



Also the specular highlights are a bit harsher with less gradation. Im not saying its bad, its all just preference. is there a way to deepen the shadows without making the overall image darker? And a way to soften specular highlights?

I have not tried the Light Cache animation mode so I'll give that a try.

I am hoping I can improve times with Vray as I use Phoenix for my effects and transferring to Arnold is an extra step.

Here is my scene file if anyone wants to try it.

[sirio76]

If you want deeper shadows you can use filmic tone mapping or a photographic LUT. If the LC is flickering just set the retrace threshold to 6/8 and rise the subdivisions a bit.
About the render speed, Arnold have many qualities but speed is not one of them, in most situations Vray will be quicker. Also it will be far more useful to use a real production scene to test the speed, rendering just a few polygons without real shaders/lights can give very misleading results.