Render times are way high , Help !

[Harlyo]

Hey guys i need your help am kinda stuck in a scene right now , i got tones of meshes scattered along the scene with 4k resolusion mostly & 2k and high res meshes makes total of 11 million polygons , am also using distant & doom " with HDRI " light as the main light source for the scene and there is trees , leaves , rocks so you get the point 🙂 , the meshes are instanced not copies and testing the render yesterday on lowest render settings after 10 hours only about 3% was done , i dont know why its very slow am not using displacement , and also am not using procedurals which i dont know if it can slow render time or not i know it makes the scene lighter in the viewport but what about render times !! it says nothing on the doc about that , so kindly i need your help what can i do to decrese the render time drasticly while not losing quality , thanks

[Stephen.Blair]

Do you have an Arnold log for the render?

I don't know what "distant & doom" is.

[Harlyo]

Distant and doom light , there was no errors in render log .

[pproestos · Accepted solution]

Why you have so high specular ray depth?

If you don't have detail reflections that you have to show,

value of 2 is fine.

In general don't raise Arnold values except if you know what you're doing.

Arnold is a sophisticated renderer tool far beyond from any other,

so the more you push it, the more you need sophisticated multicore computers...

Also check your resolution.

Anything more than 2000x2000 pixels you going to need a very strong pc.

Lower your resolution and use denoiser...

[Harlyo]

thanks for ur reply , yes your right about the specular depth , also am not using high res just 1920 - 1080 , i am going to use multiple passes and comps them in photoshop so is it possible to use denoiser on all the passes ! i havent used it before , also does it lose much quality with denoiser ?

[michiel.van.gasse]

Maybe Distant and Skydome?

[michiel.van.gasse]

Maybe let us know how many samples the lights are.

Shaders also could be heavy with a complex scene.

Sss could be heavy. See if you need it, dependse on the scene.

For example use the opacity(cutout) for the leaves instead of transmission.

Maybe split up the scene in to manageable parts.

[pproestos]

@Mamdouh Fahmy Yes it loses... Personally I use topaz denoise and ai-gigapixel, if I have to do a quick render (with low samples and low res) but send it in good quality.

[Harlyo]

each light has 3 samples , for the render settings specular , diffuse , sss has a max of 2 and camera AA has 2 as well , am using also adaptive with max of 5 , i think these are not high settings right ! , there are indeed a heavy use of SSS since the scene conttains a lot of planes and leaves but i cant throw sss away and fake it i really need realistic results , so any other alternatives ?

[Harlyo]

yes thats what i mean , i also attached a log file for one of my test renders in case that helps .log2-production.txt