Sampling tutorial for V-Ray 3.20

[alexyork]

Yes, it's possible to do that. I'm experimenting to see what can be done...

Best regards,
Vlado

That's great news.. would really help to further automate things for the quickest and cleanest results.

[leo.surrealismo]

vlado, I've send you a 3dsmax scene to your email.

[SteveC]

Many thanks for the tutorial Vlado, very much appreciated. I seem to have run into a problem though,
and I don't know if it's something I'm doing or if it's a bug.

I've been using the method in the tutorial on a scene and experimenting with settings etc, however
I've found that if I go back to using light cache and irradiance map 3DS Max crashes as the render reaches
IR map calculation. It's done it 6 or 7 times now and in a couple of different scenes, I use the tutorial
method, then go back to using LC and IR map and 3DS Max crashes.

I've made sure that render settings are put back to the same as before using the tutorial, Image Sampler to
progressive, Global subdiv Multiplier back to 1, even tried using the quick scene setup for interior LC/IR map
and still crashes.

Can any one else repeat this or am I simply doing something wrong ?

Cheers
Steve

[peterguthrie]

We could provide a version of our Carey House for Vlado to use as an example if people think it would be a good test bed? lots of trees, gravel, but also large plain areas in the interior.

http://www.the-boundary.com/carey/pw...ycbjnk8hkwtbjw

wouldn't be till next week though, I'm currently on holiday

[pixela]

Yes, and no.
In other words, no MSR will clean your super-thin geometric edges/detailed textures/moblur/dof enough with too low a number of AA rays. You WILL need AA for those.
And that is why Vlado shows the per-object trick to ignore the MSR value (which will perhaps become automatic later on).

1. So is it possible to say, higher AA subdivisions are needed for geometry-based details and higher MSR for material based details such as glossiness etc?

2. For example a masonry wall with vray displacement (with a hi-res map)
As far as I understand, we need to raise AA subdivisions. Right?

3. If we increase MSR and keep max subdivisions same,
then will we have more noise and less detail on geometrically-intricate areas?

[pixela]

Hi Vlado,

I have a question regarding lowering the subdivision of the vrayfur plane.
If I understand correctly, you intend to decrease render times when you make the subdivions of the plane 0.
But does this also mean less detail and accuracy on that object?

[vlado]

But does this also mean less detail and accuracy on that object?

No, it just means the calculations are split differently between the image sampler and the shaders.

Best regards,
Vlado

[pixela]

No, it just means the calculations are split differently between the image sampler and the shaders.

Best regards,
Vlado

Hi Vlado,
So what do we exactly tell Vray when we make the subdivisions of the plane 0 - Would you please explain ?
Why does it render faster if this doesn't mean less detail?

I am trying to understand the theory better and I would be very happy if you can give me an idea on these questions:
1. Is it possible to say, higher AA subdivisions are needed for geometry-based details and higher MSR for material based details such as glossiness etc?

2. For example a masonry wall with vray displacement (with a hi-res map)
As far as I understand, we need to raise AA subdivisions. Right?

3. If we increase MSR and keep max subdivisions same,
then will we have more noise and less detail on geometrically-intricate areas?

[peterguthrie]

On the attached, the top row is all set up as Vlado describes, except noise threshold of 0.01.

The second has a vray properties subdiv multiplier of 0.0 on the grass and trees.

So Pixela, as I understand it, it means vray somehow spend a bit less time on these areas and it is left up to AA to deal with it...

makes for a small increase in speed, but not quite what I was hoping.

I can do more tests if someone tells me what to do, and I can send you this scene to use for a tutorial Vlado if you want?

Peter

[vlado]

Sure, the more scenes the better

Best regards,
Vlado

[pixela]

[ATTACH=CONFIG]25426[/ATTACH]

On the attached, the top row is all set up as Vlado describes, except noise threshold of 0.01.

The second has a vray properties subdiv multiplier of 0.0 on the grass and trees.

So Pixela, as I understand it, it means vray somehow spend a bit less time on these areas and it is left up to AA to deal with it...

makes for a small increase in speed, but not quite what I was hoping.

I can do more tests if someone tells me what to do, and I can send you this scene to use for a tutorial Vlado if you want?

Peter

Thanks Peter So if I understand correctly, when we make the subdivisions/object=0, vray disregards any material settings related to the object and use AA (at highest level in this expample). I just didn't understand why the render is faster as there is higher sampling in second image.

[Vizioen]

Hmm isn't AA suppose to take longer?

[super gnu]

yes but if you * need * lots of AA for an object (i.e. fur) setting the local subdivs to 0 gives you lots of AA, *without* lots of secondary samples per AA pass.. since the AA will deal with those issues anyway, its better to just give lots of AA to those objects rather than lots of AA *and* lots of secondary samples.

[alexyork]

Vlado, I think we're gonna need another one of your fine video tutorials for this! A little "advanced sampling" chapter, perhaps.

Also, eagerly awaiting your video(s) for Secondary Illumination and others.

[Vizioen]

yes but if you * need * lots of AA for an object (i.e. fur) setting the local subdivs to 0 gives you lots of AA, *without* lots of secondary samples per AA pass.. since the AA will deal with those issues anyway, its better to just give lots of AA to those objects rather than lots of AA *and* lots of secondary samples.

Alright, I get it