Vray RT 3.30.01 Issues

[Donfarese]

Here is another example rendering at 720p this time using my Geforce driver 353.62 and then the newer 358.91. I can tell you by the behaviour it does not seem like vray RT 3.3 is respecting the Max Noise 0.005 setting like vray 3.2 did. Usually when the render hits that max noise setting the progress bar starts shooting across and finishes up the rendering quite quickly. But not on 3.3, just a steady slow progression.

Driver 353.62 25min 30 sec

Driver 358.91 20min 47sec

[Donfarese]

Forgot to answer your question, yes the couch and chairs should be white, the rt render is wrong. CPU renders it correctly.

[vlado]

I can tell you by the behaviour it does not seem like vray RT 3.3 is respecting the Max Noise 0.005 setting like vray 3.2 did.

We will check this, of course, but I'm pretty sure that it is not a bug. The noise threshold does work differently between the two versions. V-Ray 3.2 could leave areas noisy and stop sampling them even though they did not quite meet the specified noise threshold. So you could actually say that 3.2 was not respecting the noise threshold. We had a few customers complain that V-Ray RT GPU could leave parts of the image noisy no matter how low the noise threshold went. So we fixed it, but of course it means that now in 3.3 some parts of the image are sampled for longer than they were in 3.2. However the noise levels should be more predictable and similar to what the CPU renderer does.

Best regards,
Vlado

[Donfarese]

It seems to sample twice as long though. I'll run some more tests, but I never had noise issues with 3.2 and it rendered much faster. I though the new sampling meathod would render way faster especially for this scene, but according to Blagovest the new sampling isn't even on on my scenes.... Don't know.

[vlado]

The noise threshold works differently regardless of whether the new adaptive algorithm is on or off. You may not have had issues with the previous method, but other people did.

Best regards,
Vlado

[Donfarese]

How do I turn on the new adaptive algorithm, and how do I turn off the prepass since mine seems to be on by default. I used the command line command I found in another thread but it did not seem to turn on the new algorithm since Blagovest said it didn't seem to be on. And how do I tell if it's on or not?

[vlado]

How do I turn on the new adaptive algorithm, and how do I turn off the prepass since mine seems to be on by default. I used the command line command I found in another thread but it did not seem to turn on the new algorithm since Blagovest said it didn't seem to be on. And how do I tell if it's on or not?

Best way is to just reset the settings (i.e. set the renderer to default scanline and then back to V-Ray RT). This will enable all new options and disable any prepasses you might have added.

Best regards,
Vlado

[savage309]

Okay, the new scene that you have send us renders fine, so finally we can reproduce and examine what is going on in details.

The prepass you are seeing is coming from a reflection interpolation, which is turned on for the material "Blue Plastic" (in the log I think there is something like "Registering reflection interpolation map for material "Blue Plastic).

In the new scene that you have send, the new adaptive algorithm is on, and the longer render is due to the changes in the noise threshold calculation and in the image sampler. The longer render is as clean as expected, so everything is okay. Slower would mean to get noisier result for the same amount of time (or same result for different amount of time), but this is not the case here.
If you want to have the old behavior, you can try putting that as a MaxScript:

renderers.current.V_Ray_Settings.twoLevel_adaptive Method=0

Without the space between 'adaptive' and 'Method' ... not sure why, but the forum adds that ...

Both the noise levels and the render times should be very near to those of 3.20 (with that MaxScript command, 3.30 is a bit faster on our machines, actually).

As an alternative, you can skip adding that command in the Max Script and play around with the scene, increasing the noise threshold to about 0.013, which will make the scene to render for roughly the same time, but the noise should be generally more even (for your scene, the refrigerator and the floor for example will be more clear, but the walls would be a bit more noisier).

We also found the bug with the yellowish couch and we will do our best to fix it for the final build.

If there is something else, don't hesitate to ask.

[Donfarese]

Hi Blagovest, thank you for looking into this, I actually found the same results last night when I realized using the original scene from 3.2 rendered in 24min and the one I sent you that I reloaded vray for the new algorithm rendered in 52min. I posted the rendering results below. you can see the new algorithm is cleaner, but is about twice as long to render. I am going to play with render setting to see if I can get the same results in with the new algorithm in roughly the same old time. I guess I was getting confused because I thought the new algorithm would have been much faster to render, seeing some of the results in other threads. Also from tests before seems that the new Latest geforce driver are the fastest to render with shown in my examples earlier, will be trying more drivers to confirm. With 3.2 we had to stick with 353.62 drivers or our render times would go up by at least 10sec per every minute. Another question, I have access to the nightlies, but I don't see anything but vray for blender? Where are the vray for 3dsmax?

[savage309]

The new image sampler algorithm does not makes the rendering faster (neither in the GPU nor the Production CPU render). It just makes the noise more even around the rendered image. And it surely decides at different time when the render is 'done', but I am not familiar with the image sampling algorithms and I can't give you more details on that since I am not an expert.
If you want to have the same render time with the new sampler set the noise threshold to around 0.013 (or use the old sampler, which will give you the same render time and noise levels as before).
For the nightlies, please contact support@chaosgroup.com.

[Donfarese]

Okay I ran a new Test. Have to get use to the new workflow settings I guess. Below you can see a test between Max Noise and render times. Guess the only thing left is the bug for color and hopefully working 3dsmax process for having a different secondary GPU. Any progress or ideas yet on the 3dsmax process issue?

[savage309]

We will fix the color issue, but I can't promise anything for the GPUs issue you have, since it is not only up to us.

[Donfarese]

Okay no problem, I'll see if we can do something with our setup. Wish TCC worked better, we had to much over heating issues using that. Maybe I'll start a new thread about that and see if others have ideas. thanks for all your help!

[Donfarese]

Hi Blagovest, Here are more examples of the difference from RT to ADV. I thought the diffuse textures was the only difference (BUG). but it seems that Reflections, Transparencies, Lighting....etc. is also rendering different. Here are the settings I use also, I don't know how they really translate over to one another to get them exact for rendering and Time comparisons.

How do I post an animated gif?

[Donfarese]

Okay I noticed issues do to using under materials in the bitmap using output adjustments, clamps, etc. Not sure yet on reflections and lighting differences. Also color correction.