Render Settings Question.

[short cirkuit]

Hi guys

I have a question for the latest vray in regards to render settings. I followed Grant Warwicks youtube vid on vray sampling. Now he suggested that for most scenes, things are best left at default and he found that for the image sampler, min subdivs of 1 and max subdivs of 50 + colour threshold of .015 seemed to work well generically. Im doing this for my high res renders at 4000k resolution and the renders look fine. A little bit noisy but annoyingly, the vraylight select passes for my lights have a lot of noise in them. How do i control this and make it more high res for the lights?
You see, Im not at all cluey when it comes to render settings! Ive asked here a few times for a complete idiots guide but it has seemed to have fallen on deaf ears so here I am asking something more specific.
I would hugely appreciate any direction with my question for the lighting and how to achieve higher res/noise free'ish light passes but would be even more grateful for a comprehensive explanation on how to sample for the latest vray - hope in not asking for too much

Stay cool guys!

[short cirkuit]

crickets - i hear crickets!

[joconnell]

So!

You've two aspects to look at - geometric and pattern detail, lets call those "edges" - where you see the silhouette of your object or it's shape. You also get the same thing with texture detail - if you've got a pattern, the pattern has edges and shape in it too. In vray the quality of the edges changing between blocky and smooth is controlled by your anti aliasing settings. For really simple large soft objects, a min and max of 1 / 8 can often be enough. If you get into objects that are very thin or have a lot of fine detail (think stuff like fur, grass, hair which might be detail that's a pixel wide or sometimes less) then you have to give the anti-aliaser enough chances to see that detail. A simple way of thinking about it is when vray looks out into your scene, that's an anti aliasing ray. It fires an anti aliasing ray into each pixel of your render and if the object is smaller than a pixel, there's a chance the AA ray will miss it, that's why you have to start using more than one anti aliasing ray (hence you've got a min and max value for this - smaller for all the easy objects, higher for all the finer more details objects - best of both worlds). So if the silhouettes of your objects are good enough, then you don't need to change your min or max aa.

Second aspect is shading. Shading is going to be how clean your lighting is, your bounce lighting (only if you're using brute force - irmap and light cache are always smooth but they can be mottled / blotchy instead. They'll use different quality controls so we'll avoid that conversation here.), your reflections, your highlights. This is controlled in vray using the minimum shade rate control. Again like your AA, vray is going to fire rays for your lighting around the scene and try to see what lights are hitting your object, it's going to fire reflection rays to find what objects should be reflected in the surface of your object and other such things. If you don't give vray a lot of rays to do this in, you can kind of make out all the individual variance between all the things vray saw. If you give it lots of chances to look around the scene, what'll happen is there'll be smaller gaps between the individual things and they'll start to blend into each other far more smoothly rather than individual dots (most people call this "grain" in their renders). In vray, the higher you turn up the minimum shading rate, the more rays it'll use for your shading and you'll get much nicer results.

Lele has written a handy "cheat sheet" for this approach and vlado has recorded a video on youtube to explain it:

http://forums.chaosgroup.com/showthr...ht=cheat+sheet
https://www.youtube.com/watch?v=tKaKvWqTFlw

Hope that clears some of it up!

[short cirkuit]

hey mate - thanks so much for the explanation - you've explained it perfectly.

In regards to Lele's cheat sheet though, he doesnt touch the MSR, just the min/max sub divs + the noise threshold. ALso, on a realistic scene (lets say an interior scene), if I am to render it at a final resolution of 4k wide, do i do region render tests on 4k or can one do so on a much lower resolution? Im not sure how to go about it for the final render if that makes sense.

Thanks again your explanation and time is appreciated.

[joconnell]

Lower resolution can give you overall trends but aa only really works at full resolution where all the detail is going to be the final size - try things like simple override materials and turning off GI if you want to judge only edge detail for example, regions for shading. Lower res tests can be handy for identifying where the nosiest and cleanest areas in the scene are so you know where to look at full res!

[short cirkuit]

awesome makes perfect sense thanks for clearning this up for me its much appreciated.

Lower resolution can give you overall trends but aa only really works at full resolution where all the detail is going to be the final size - try things like simple override materials and turning off GI if you want to judge only edge detail for example, regions for shading. Lower res tests can be handy for identifying where the nosiest and cleanest areas in the scene are so you know where to look at full res!