Small script to quickly change vray material reflection subdivs based on glossiness

[MoonDoggie]

Yeah I've been using one similar for a while and it's helped a ton. Thanks for the info Cubicle.

[leo.surrealismo]

( Crtrl + E ) o (evaluate all) before dragging to a toolbar

[Morne]

The max depth creates havoc for the type of scenes we work on nowdays
If we lower it, the render does go quicker but it looks real bad

We have a ton of glass and metal overlapping like balustrades, lift shafts etc

[joconnell]

Yeah that's what I do - I've a second script that does max depth based on glossiness - if you've something really soft you won't get much difference beyond the first bounce save for a little bit of brightness.

[Neilg]

We have a ton of glass and metal overlapping like balustrades, lift shafts etc

Render with the glass off and drop it in as a separate pass. your render times will speed up a shitload more doing this too.

[voltron7]

anyone else using this find it stopped working after latest 2.4 build?? (4-28-2014)

[super gnu]

the thing i dont get about this concept of setting the subdivs based on the glossiness is this.. isnt this something vray already does for you? subdivs are only a max value, and if a material has a sharp reflection, vray wont use all the subdivs and will reach the noise threshold easily. when a material is glossy it will shoot more rays up to your subdiv limit to reach a clean pixel value. therefore if your subdivs are high enough it should shoot the minimum number of rays for each material to achieve your given noise threshold.

this has always been my understanding of how it works.

i mean, obviously if people are finding this setup reduces their rendertimes then im all for it and will try it myself, but it seems to be doing something vray should handle internally... ?

[joconnell]

Sure, you're absolutely right. In theory if all adaptivity was working perfectly, you'd just set every subdiv parameter to a million and let vray sort it out via your noise threshold.

Here's my thinking on it though. If I'm doing something that doesn't use depth of field or motion blur, I generally go with just enough AA and high sampling on lights and materials. If I'm going for motion blur then I go high AA and low materials and lights. In the case of the low AA bits, I only want the high AA rate to operate on the geometry edges of my objects. If vray spots any noise or contrast in any of the channels at all, it'll force the aa sampler to go up to whatever the next level is. If I'm using aa 1/8 on a scene that's geometrically simple but maybe has glossy materials or lots of soft lighting, both can be sources of noise. With simple objects, you'll likely get higher AA sampling around the edges / silhouette of your objects which is fine as where edges meet will probably be areas of separation and contrast. For the middle pixels of the object though, especially if it's a smooth object, you'll get less contrast from pixel to pixel so you won't need high AA. What tends to happen though, is ANY source of contrast in your render (read noise - contrast between a group of pixels) will go higher than your colour threshold and cause vray to go up to the next level of AA for those pixels. What I'm essentially doing is taking into account that vray will divide whatever value I have on my subdivs by whatever the max AA number is. I'm trying to make sure that for those middle pixels on a smooth object, we get clean enough results in our lights and materials so that our colour threshold is satisfied firs time around so that vray can finish those pixels successfully at AA 1.

In terms of the script, it's kind of a generalisation on my part to think that a blurry reflection will definitely be noisier than a sharp reflection and need more samples seeing as it'll see a broader range of your scene. My whole idea is you want to try and feed vray with as many subdivs as needed to meet your noise threshold on aa 1 and not on aa 8.

As ever there are lots of approaches in vray so give it a go and see if it behaves for you!

[Macker]

In terms of the script, it's kind of a generalisation on my part to think that a blurry reflection will definitely be noisier than a sharp reflection and need more samples seeing as it'll see a broader range of your scene. My whole idea is you want to try and feed vray with as many subdivs as needed to meet your noise threshold on aa 1 and not on aa 8.

It's a good idea. Seems to me the whole "universal settings" approach is geared towards using the AA filter to clear any and all noise. A sledgehammer to crack a walnut approach.

[super gnu]

ok so i guess my question should be.. why doesnt setting all your subdivs to an arbitrary high value have the same result?

i know it doesnt as cranking up all subdivs kills rendertimes, and if it did, there would be no need for a subdiv control on each material at all.

but i guess im still not sure why the adaptive system even needs per material subdiv settings if the aim is just to get the right number of rays for a clean material every time.

i assume its due to a gap in my understanding.

[joconnell]

It's a good idea. Seems to me the whole "universal settings" approach is geared towards using the AA filter to clear any and all noise. A sledgehammer to crack a walnut approach.

Kind of. what I've found with universal is it's very handy for scenes with motion blur - you'll always need high aa for that and depth of field, so you might as well take advantage of it while you're there. I've found with a high max aa number though it's slightly harder to get elements clean (since vray is only ever doing sampling to make your beauty, which comes out great with universal) and I'm always passing those over to compers to mess around with.

As usual depends on your scene!

[voltron7]

well, I've found it helps reduce my render times, as well as fussing time. So, has this broken for anyone else lately? Or, is there a new version?
Well, got it working again...it was some imported material causing the problem.

[larissa_thomazi]

Some one can help me am tryng to do this same script for COrona, to change all the settings for the selected materials but dont working:

Code: