Bring back motion blur and DOF subdivisions (vray 3.0)

[Jussing]

Hey devs,

removing the subdivisions from the motion blur settings is a real PITA to the workflow.

Before, I could flick motion blur on and off during any step in my work flow, for test rendering, and the extra AA for motion blur would only be active during motion blur. Now you'd have to go back and forth in your AA settings, too. And have a little postit on the screen about the optimal motion blur/no motion blur setting per scene...

The new thing is not a major show stopper or anything, but it's a usability issue that was fine before, but now it's annoying.

I know this thread says there was never a "motion blur only" control, but in effect there was, since the extra subdivision was only on when motion blur was activated.

Thanks

[Jussing]

Not to mention that fixing the AA to produce similar results as if I was to increase mblur subdivs is, at least for me, much more complicated.

In a simple example with a teapot flying fast by the camera, vray 2.5 produces grainy mblur at the default subdivs - so I increase it till it looks good, which is around 18, which renders in 8 secs.
In Vray 3.0, even if I set max subdivs to more than a hundred, I still get grain. So I have to experiment with the minimum subdivs, which starts to affect render time noticeably. I end up with an 18/18 setting before I match the grain-free quality of Vray 2.5, but the render time is now 36 secs.

I'm sure the new way technically makes perfect sense from a developer's point of view, but it's not what the artists need - please bring back the old UI, it does exactly what the users need.

[Svetlozar Draganov]

Tweaking AA settings includes not only Max Subdivisions levels, if the the quality is not sufficient even with hundred of subdivisions then most probably the Color Threshold value (or DMC Threshold value,if Color Threshold is locked to it) is too high. Try to set the Max SubD = 18, leave Min SubD=1 and decrease the Color Threshold Parameter - you should be able to get the same quality like in 2.5 for even less rendertime. If that is not the case please send the scene for investigation.

[Jussing]

Thanks Svetlozar.

But what you say perfectly illustrates my point.

The procedure you describe is much more complicated than what you had before.

Plus, by making that change I'm also changing the render settings to be unnecessarily high, for when I disable motion blur 10 minutes later, for testing.

Really, this is a feature that worked, that is now broken.

[vlado]

Unfortunately this is not coming back.

Best regards,
Vlado

[Jussing]

Even with a color threshold of 0 and a rendertime of 40 seconds (versus vray 2.50's 5 seconds), I'm still getting more grain. Of course I could experiment with further increasing the max value and then decreasing the color threshold again.

But again, this illustrates how the new setup is gibberish compared to the old one. You have to bring it back, this new thing makes no sense.

Why did you change it and why is it not coming back?

[vlado]

Even with a color threshold of 0 and a rendertime of 40 seconds (versus vray 2.50's 5 seconds), I'm still getting more grain. Of course I could experiment with further increasing the max value and then decreasing the color threshold again.

Then it would be best to get me a scene to vlado@chaosgroup.com - it may mean there is a bug somewhere.

You have to bring it back, this new thing makes no sense.

If there is a bug, I'd rather we fixed it. You should be able to get the same or even better results for faster render times; if that's not the case, like I said it may mean there is a problem somewhere.

Best regards,
Vlado

[Jussing]

Thanks Vlado, I've sent it to you now (had sent it to support with Att: Svetlozar).

[Svetlozar Draganov]

It seems that there is a bug with Image Filtering in Vray 3.x since the noise comes mainly from it.
Please uncheck Image Filter option in both version 2.5 and 3.0, then use the following settings in Vray 3.x and you will get the same image quality but Vray 3.x will render it twice as fast.


We'll add this bug into our system.

[vlado]

No, there is no bug. You will get the same results with V-Ray 2.5 if you increase the AA subdivs.

Best regards,
Vlado

[Jussing]

Vlado, please download my new teapot test scene (I've increased resolution, subdivisions and polygons to get longer render times, to get more useful comparisons).

http://jussing.dk/transport/vray_mblur_subdivs28.max (I will also mail this to support)

Attached are my test renders, that compare an AA 1/28 render from Vray 2.5 with various settings from 3.0.

The process of testing combinations of the four parameters that have been mentioned by Chaos Group developers and support, is a time-consuming puzzle compared to the subdivisions of 2.5, and I still haven't figured out what settings I should use to match the quality of 2.5 without tripling the render times.

Can you please tell me the optimal render settings for matching the quality of 2.5? Thanks.

Cheers,
- Jonas

[joconnell]

Bit of an oddity too - if I render this with min AA of 1, it's missing the corner of one of the buckets at the top right of the teapot. I'm using the vray_adv_30507_max2014_x64_24748 nightly. If I up the minimum aa to 2 or the geometry samples in the motion blur to 3 we've no issues so it's solvable but might be a thing worth looking at.

Thanks Svetlozar for the Image filter tip too - you're right about it causing extra grain!

Here's the naughty bucket:

[Dave_Wortley]

Bit of an oddity too - if I render this with min AA of 1, it's missing the corner of one of the buckets at the top right of the teapot. I'm using the vray_adv_30507_max2014_x64_24748 nightly. If I up the minimum aa to 2 or the geometry samples in the motion blur to 3 we've no issues so it's solvable but might be a thing worth looking at.

Thanks Svetlozar for the Image filter tip too - you're right about it causing extra grain!

Here's the naughty bucket:

[ATTACH=CONFIG]20313[/ATTACH]

I've had that happen a few times, buckets rendering black, often with Shadow pass, easy fix is to increase bucket size.

[joconnell]

Cheers - I'd say what's happening might be a minimum rays / samples thing where it's firing rays into the bucket that are just missing the geometry due to the temporal aspect of motion blur being added, and early termination is kicking in giving us a blank result.

Svetlozar / Vlado :

Just as an aside it turns out that missing bucket error is down to the lock noise pattern checkbox. I re-opened the file to confirm the error based on what Dave had mentioned, out of the box with Jussing's file there's no issue but as I was fiddling with the file with the settings I'd normally apply it was turning off lock noise pattern that made the bucket drop out. I'll pretty much always try to use min 1 aa cos I'm cheap but I'll also have lockj noise turned off so the grain dances on any of my moving renders. Here's the file with the error if you render with the vray_adv_30507_max2014_x64_24748 nightly - this might be a glitch only in this version though.

vray_mblur_subdivs28_vray_30507_lock_noise_pattern_off.zip

[kosso_olli]

Bit of an oddity too - if I render this with min AA of 1, it's missing the corner of one of the buckets at the top right of the teapot.

I had this a lot of times in the last few weeks, also in scenes with no motion blur at all. Last recent case was a simple greyshade of a car interior, nothing special in that scene except for a domelight and a grey override material. It seems to be happening in older versions of Vray too, because one of our Maya guys had the same issue in 2.4