General/optimal render settings for car renders

[plodej]

We have been testing VRay for Maya for the past 3 months and have a few questions regarding general render settings. We are rendering at full HD 1920x1080, but our render times are at times excruciatingly long. From you own personal and professional experience what are the optimal render settings? We realize that each scene is different and that there are many factors that dictate render times, but what are some proven settings that give good quality at decent speeds? Our current average car scenes vary from 12minutes to 2 hours.
Our settings are the following:

Adaptive DMC
AA filter: Gaussian 1.5
Adaptive DMC: Min 1, Max 100, Threshold .009

Indirect Illumination: ON, Caustics off
AO: On

Settings: Adaptive Amount: .85
Adaptive Threshold: .01
Min Samples: 25

Our paints at times, especially white, are quite noisy. The refections are grainy and fuzzy.
So in general what are the optimal render settings for decent render quality and render speeds? Any suggestions are very much appreciated. Thank you

[Paul Oblomov]

I don't quite understand why you need some optimal settings. It all depends...
I thnk the best way is to turn on rawreflection render element and tune it, until you satisfied with noise amount (global mult, light mult, maybe lc for glossy, noise thresh etc....) And I really like starting from DMC 1/12

[Dariusz Makowski (Dadal)]

That some interesting settings... I would suggest Subdivision DMC for automotive since it produce a loot smother noise for the same render time.. and lets say min 0 or 1 and max 2 or 3.

NO GI no need that...

I would not bother with Advance settings just leave them at standard.

Id set up each material from 24+ samples depending on glossines..

And set up my workflow to be pass based not beauty bassed.

[Yannick]

Hi,
here is what I use:
Adaptive DMC
AA filter: lanczos 1.5
Adaptive DMC: Min 1, Max 50, Threshold around .005 but that changes but projects

Indirect Illumination: ON, Caustics off Irradiance Map (with low values make it smooth) and Brute force (default)
AO: as a seprate render layer so it is rendered separtly on our farm

Settings: Adaptive Amount: 1
Adaptive Threshold: .01
Min Samples: 8

I also leave all my sample on material and lights default.

This usually give me a good result at a reasonable render time. Obviously it all depends on your scene.

Yannick