So, Vray is "SOOOO FASSSSSTTT" (and not too grainy btw).... if :

[jop]

- you work with Irradiance/Ligh cache
- you check "store with irradiance map" for each VrayLight (finally you can increase subdiv)
- you use Adaptive DMC sampler (value such as 1/3, 0,005 seems great to me for quality vs time)
- you check "use light cache for glossy rays"
- you Always "Treat glossy rays as GI" in your materials (and say goodbye to these white dots)

Feel free to add some ones.

I spent long time before finding these obvious little things, just wanted to share it for those who still don't understand why
they read everywhere that "Vray is so fast", and keep waiting 24 hours for a 320x240 render with 0,00000000001 threshold....

Cheers !

[tammo]

I agree and use almost the same settings in most projects.

The only thing that can cause problems is "store with irradiance map" for each VrayLight.
Somehow this changes the way the glossy reflections look but it is a lot faster.

Checking "sub-pixel mapping" and "clamp output" can also speed up rendering in some scenes.

[pskdude]

i would also throw in a portion dedicated to Vray Proxies.

[3DMK]

-
- you Always "Treat glossy rays as GI" in your materials (and say goodbye to these white dots)

So is this the setting that gets rid of those very very problematic white dots when Sub-pixel mapping is OFF??
Does it reduce the quality in anyway using this setting???

Thanks

[jop]

2 issues :
- white dots due to low antialiasing, this is what "Treat glossy rays as GI" get rid of
- bright pixel burning (linear value above 1.0), corrected by sub-pixel mapping & clamping

More info here :
http://www.chaosgroup.com/forums/vbu...at+glossy+rays

[Subburb]

i'll add :
- reduce a little bit irrmap interp samples if possible
- don't use any image filter !

[jop]

what do you mean by :

- don't use any image filter !

?

[Subburb]

I mean : antialiasing filter located into "Vray:: Image sampler (Antialiasing)" rollout.

just uncheck tu use no filter.

i just made a try on an heavy scene (displaced grass + lot of trees):
With Catmull-Rom AA filter : 3m58s
With no AA filter : 3m14s
gain : 44s --> 20% !!!

[jop]

Ok, I understood just after posting, and took time to give it a try... impressive !

I made a side by side comparison, no filter vs mitchel.
I don't see any difference. So I wonder why using filter ?

Did you make some test in animation, may it introduce some flickering ?

[Jiri.Matys]

Yes, I using a same settings

irradiance/Light Cage
sub-pixel mapping and clamp out on
non image filter

[davision]

As Jop asked, I would like to know when to use a filter? Is it only helpful for animation?

[thomaskc]

Hey guys, interesting theory about the filter and no filter, never thought about disabling it, but it seems to work fairly well on stills. I sure would like to know the if there is a real difference, maybe in highres rendering?

[instinct]

One thing filtering helps fighting is moiree, in animations noise is also a lot more appearant than in stills.

Regards,
Thorsten

[Subburb]

you can also gain a little bit on beauty pass (dmc AA) when increasing render size (stills).
each time you double the render size, it correspond to a subdiv.

So for example if your pic in 800*600 is great with AA 3-6 then you can render it with AA 2-5 in 1600*1200. You'll theorically get the same result.
This kind of optimisation is managed automatically by solidrocks, to help gain time when increasing resolution.

[^Lele^]

One thing filtering helps fighting is moiree, in animations noise is also a lot more appearant than in stills.

Vlado let slip an interesting thought about image filtering in his PPT tutorial:
"Note that sharpening filters (Mitchell-Netravali, Catmull-Rom) may introduce noise and will require more samples to produce a smooth image. Larger filters like Blend may also take more time to converge. Turning the antialiasing filter off produces the least noise."

The speed increase resulting through turning filtering off can be used to add more DMC sampling, hence getting rid of noise.
Using blurring filters, on the other hand, makes the noise crawl (as it goes from 1 pixel in size, to the 1.5 pixels for Area, for example), and also a wee bit harder to manage in post.
From my past experiences, turning AA filtering off entirely is the smartest way forward, as noise can be post-processed (ie. filtering to the image is added after the render) from its original 1px size.
Moire effects can be fixed only through filtering of the BITMAP, as when left to be cleaned by the AAser, that results in humongous rendertimes, compared to a pyramidal pre-filtering of the image generating it, for example.
You can see the results of this approach in Dragonball:Evolution (all the end bits with a gazillion trees in the "desert") and G.I.Joe (the tank being eaten by nanomites at the start of the movie).

my 2 cents.