Which image sampler to choose?

inbal

Hello everyone,

I am trying to have a really good idea on what image sampler to choose:

I did some research and found that the
Addaptive DMC - is the best for interior renders where there are lots of textures and reflection, but it is slow.

the Adaptive Subdivisions is good for fast renders because it takes less time or for good renders when there are not many textures and reflections.

But I havn't found an answer to -

the fixed rate- when is it good for? when will I use it?
when min and max rate to set for every sampler?

I would really appreciate if someone could make it really clear for me.

thanks

Stinkie

Don't use the fixed sampler. It's great quality-wise, but it'll slow your render down to a crawl.

The adaptive subdivision sampler I never use myself -interiors tend to have high detail textures, lots of blurry reflections etc. So that leaves the adaptive dmc image sampler.

Settings for tests: min rate 1 (I never change the min rate), max rate 4, threshold 0.01. Dmc sampler settings: default.

Final render settings: min rate 1, max rate 8, threshold 0.005. Dmc sampler settings: adaptive amount 0.85, noise threshold 0.005 (lower = better quality), min samples 8 (higher = better quality), subdivs mult 2 (the default is one; by changing this value to 2, you're effectively doubling every subdivision setting in your scene. The quality of DOF, IR cache, brute force GI, reflections, shadows etc will increase.)

inbal

thank so much

Stinkie

No problem. Do investigate further, though. Taking my word on the inner workings of Vray as gospel may quite possibly not be the best of ideas. And check this out: http://www.thegnomonworkshop.com/store/products/tutorials/cni03/

eidam655

and additionally maybe these tutorials http://renderstuff.com/free-rendering-cg-tutorials/ and specifically this one http://renderstuff.com/best-vray-settings-dmc-sampler-cg-tutorial/ could clear up some other stuff. (yes, it'sprimarily for 3dsmax, but it's for vray, and that has the same settings universally, so it can teach you/us something.)

inbal

@eidam655 said:

and additionally maybe these tutorials http://renderstuff.com/free-rendering-cg-tutorials/ and specifically this one http://renderstuff.com/best-vray-settings-dmc-sampler-cg-tutorial/ could clear up some other stuff. (yes, it'sprimarily for 3dsmax, but it's for vray, and that has the same settings universally, so it can teach you/us something.)

thanks! sure is a lot of reading but hopfully I will get to it soon.

valerostudio

All the research I have done has always pointed to Adaptive DMC being the best. Production HQ settings being 2 Min and 6 Max with threshold set to .005. I have also read to leave anti aliasing off but have seen tutorials by Evermotion for V-Ray for Max using Catmull Rom.

Stinkie

You could use an AA filter -nothing wrong with that. However, turning it off and sharpening in Photoshop offers more flexibility.

valerostudio

Agreed. I much rather turn it off, save the render time and use Unsharp Mask in PS.

eidam655

@unknownuser said:

You could use an AA filter -nothing wrong with that. However, turning it off and sharpening in Photoshop offers more flexibility.

now that's an interesting idea. thanks

andybot

That is kinda interesting... But then you're not getting supersampling (vray calculates 1.5 or 2 pixel width per final resolution) You'd need to increase the output resolution so you can downsample to where it would be without the AA turned on.

Stinkie

Cool, didn't know that. I do know rendering without an AA filter and sharpening in post is supposedly less accurate than rendering using a filter. I'm sure that's correct, but I've not noticed any adverse effects myself.