My V-Ray concerns -- please tell me I'm wrong.

[vlado]

Well, like we discussed, I dug up the V-Ray 1.5 code and recompiled it so the truth shall be revealed soon

Best regards,
Vlado

[Morbid_Angel]

@svetlozar.draganov

Well, like we discussed, I dug up the V-Ray 1.5 code and recompiled it so the truth shall be revealed soon

Best regards,
Vlado

wow…can’t wait to see the results

[Vizioen]

@duke2

The point I was making wasn’t so much about rendering being short or long per se but more about the fact that I had the feeling I had once be able to render similar scenes noise-free in older V-Ray versions using the approach of the time (lengthy setting optimizations by hand) than I was now with more recent versions using the recommended default settings. I also felt that some scenes today were not able to resolve noise-free in what I would call an acceptable time. This is all very subjective, of course, but in the old days, when we were all still using bucket rendering, you could roughly gauge how fast or slowly a hi-res still would render by watching the first buckets resolve. If the first buckets got stuck doing nothing for 20 minutes, you knew there was a problem with your settings. In the latest version of V-Ray, I felt (again, subjectively) that I was getting too many of these scenes where, when switching to bucket mode, the buckets stayed stuck, suggesting a very long render time for the full image.
Like I said, this is nothing scientific and it may be that I’m comparing apples and oranges since my scenes today are obviously more demanding than what I was doing on a smaller system with V-Ray 1.5.
That said, I would expect an interior still at 3K to resolve fully in something between 2 and 5 hours on a twin Xeon (32 cores).

Well I’m not quite sure but could this also be related to the BRDF you might be using? I tend to use GTR for everything nowadays but I experience A LOT more noise with this than with a blinn or ward.

[short_cirkuit]

I did make a post on here recently regarding scene optimisation and light noise and I just read from Vlado that the portals are causing a lot of noise - looking forward to the next release as the light render passes are almost unusable for me without heavy post work masking out the noise.

[Vizioen]

The visual below is an example of a scene where the use of GTR was out of the question. I used GTR as BRDF on every material but I had an enormous amount of noise (noise that even didn’t go away after hours of progressive rendering). Changing to Blinn/Ward cleaned the render up a lot better/faster.

There aren’t any light portals here only vray disc lights to light the scene.

[vlado]

Can you get me that scene? I want to try it with the new glossy Fresnel that I’m working on…

Best regards,
Vlado

[vlado]

Yeah, it’s the same thing… I’m afraid you’ll have to redo your assets In the meantime, the alSurface material will do pretty much the same thing, so you can use that one. It will be included in the next V-Ray service pack too.

Best regards,
Vlado

[vlado]

@davexl

PS: It could also (at least partially) put end to those “how do I get this material looking right” kind of debates.

Somehow I really doubt it…

Best regards,
Vlado

[vlado]

Yep, the more scenes I have to play with, the better

Best regards,
Vlado

[Vizioen]

So I didn’t have the GTR setup anymore but I just did a quick conversion, and the result is as expected. See below. I don’t know but maybe I’m doing something wrong in terms of scene setup (lighting, exposure, color mapping). But after 20 minutes of progressive rendering and with active noise of 0.007 (30% left), it shouldn’t look like this I guess. Where can I drop the scene? It’s 230MB zipped.

Beauty:

Refl:

[vlado]

You can put it on wetransfer, or anywhere else like that, or you can email me to vlado@chaosgroup.com for the FTP info of our server.

Best regards,
Vlado

[Vizioen]

@vlado

You can put it on wetransfer, or anywhere else like that, or you can email me to vlado@chaosgroup.com for the FTP info of our server.

Best regards,
Vlado

Ok I’m sending it to your email with wetransfer, should be there in a few minutes.

[vlado]

I got it, thanks! Will post some images with the glossy Fresnel option when it’s in the builds.

Best regards,
Vlado

[BBB3]

@rikou

Well I’m not quite sure but could this also be related to the BRDF you might be using? I tend to use GTR for everything nowadays but I experience A LOT more noise with this than with a blinn or ward.

I use GTX sparingly because of the noise on large surfaces and because of the white halo on grazing-angle reflections when using high glossiness.

[mitchell_architecural]

Was there ever an update to this? When Bertand speaks, I listen.

[vlado]

@kosso_olli

Was there ever an update to this? When Bertand speaks, I listen.

For the GGX, yes - like I said we are working the implementation of glossy Fresnel. For the 1.5 vs 3.4 comparisons, so far in all my tests 3.4 is a lot faster with the same settings and for similar quality - I’m still working on some good comparison images to post. If you want to know something else, please clarify.

Best regards,
Vlado

[BBB3]

Yes, I meant GGX.

[Dan_Marks]

I’ve just come across this, and wondered if Vlado or Bertrand had considered the PC architecture Bertrand is using.

Over the past few years I have regularly use render nodes and occasionally a workstation similar to Bertrands machine, i.e. dual Xeon 32 threads, and although they work great in many occasions they have consistently given me problems in situations with high memory usage.

After doing some self initiated research into the cause a long time ago I resigned myself to the fact that this was possibly to due the motherboard architecture, in that only half of the memory is assigned directly to each CPU, to access the rest it has to cross the CPU bridge link… this is my suspected bottleneck and the cause of slowdowns.. and since I was out of time to investigate further I left it at that.

I now run watercooled i7s in a small but effective render farm now and I’m very happy with performance, and I’ve found that the latest Vray versions to be very good. When using a higher noise threshold, coupled with the denoiser and a good graphics card you can get amazingly quick results.

[vlado]

@Ka_Hassa

So I didn’t have the GTR setup anymore but I just did a quick conversion, and the result is as expected. See below. I don’t know but maybe I’m doing something wrong in terms of scene setup (lighting, exposure, color mapping). But after 20 minutes of progressive rendering and with active noise of 0.007 (30% left), it shouldn’t look like this I guess.

The issue in your case is the VRayLightMtl material in the light fixtures. There are lights there already, but they don’t cover the openings exactly and some GI rays manage to get inside and hit the bright light material.

I’ve seen this in a lot of scenes and in order to minimize this effect, for the next SP, I will be switching off the GI contribution of the VRayLightMtl material by default (although of course if can be enabled if one wants).

In any case, nothing to do with the GGX BRDF in this case.

Best regards,
Vlado

[vlado]

@Svetlin.Nikolov

Dual Xeon 32 threads, and although they work great in many occasions they have consistently given me problems in situations with high memory usage. After doing some self initiated research into the cause a long time ago I resigned myself to the fact that this was possibly to due the motherboard architecture, in that only half of the memory is assigned directly to each CPU, to access the rest it has to cross the CPU bridge link… this is my suspected bottleneck and the cause of slowdowns.. and since I was out of time to investigate further I left it at that.

The shared memory between CPUs is indeed a problem, but we also found a bottleneck in our code that could slow things down on many-core machines quite a bit. Although it typically started to show with 64 cores and more. It’s fixed for the SP, so hopefully things will run better on those machines.

Best regards,
Vlado