progressive rendering

[vlado]

One threshold is for primary image rays (the one in the image sampler). The other one is for secondary effects (GI/reflections/lights etc).

I will eventually move all but the "Lock noise pattern" options in the DMC sampler into an "Expert" section.

Best regards,
Vlado

[thomaskc]

One threshold is for primary image rays (the one in the image sampler). The other one is for secondary effects (GI/reflections/lights etc).

I will eventually move all but the "Lock noise pattern" options in the DMC sampler into an "Expert" section.

Best regards,
Vlado

So how do I go about getting the same look as when using adaptive?

If I leave the image sample threshold at default, so the DMC threshold is the same between the two, is that all I need?

or should both be the same? like how do I know without rendering several times, isolating layers of reflection, GI, light sources etc to try and guess? and how do I know when it's actually the light (subdivs) itself? and not the sampler threshold?

I understand the two controls, but I have no feel for what the values actually mean. like if I put global dmc at 0.01 and image sampler at 0.0001 do I get nicer direct light? and noisy secondary? (outside of the light subdivs) and what happens if I swap the two? of course I can just test this, but from a technical point what is meant to happen? or what's the intended use for these options?

update:
Or is half my problems with noise really more about BF/LC settings? I usually use 35-60 BF depending on how much time I have, and 1800-2500 LC. But i'm not sure if my global noise really should just be 0.01 and my BF should be at 120.

[bigbossfr]

+1 for Vlado
Personally, i like to have a lot of settings. I don't want a "toy" where when you have a problem, you can not solve the problem because you do not have the setting for this (example in Arnold few year ago : i have added DOF on my scene. The DOF had noise. To remove noise, i had to oversample all (SSS, reflection, all...). Normally i had to oversample the AA, but the option was not here. Render time jump from 15min to 2h. I was few years ago, perhaps now this problem was fixed).
I prefer to see VRay with some "advanced" users than "no brain" users.

The solution would be to hide a lot of menu for "no brain" users, and keep an advanced mode.
In my current studio for the render setting we use the easy ways :
- subdivs mult to 0
- ADMC 1 - 10
- min shading rate to 10
- DMC adaptive amount to 0.9
No more, no less, work with 90% of scenes, and we do not need to tweak any materials/lights

If we have some noise, we set ADMC to 1-20. Another noise ? 1-30...
This is no brain, and it is working.

The only problems than we see with this settings is :
- IR map doesn't work with this. Perhaps you have to ignore IR map when subdivs mult is to 0.
- if we use DomeLight or DirtNode, we have more noise by default (with ADMC to 1-10). Perhaps you have to add more subdivs by default when subdivs mult is to 0 for DomeLight or DirtNode (and i think there is another nodes).

After this, why you do not add this "settings" for "no brain" users ?

[Morbid Angel]

+1 for Vlado
Personally, i like to have a lot of settings. I don't want a "toy" where when you have a problem, you can not solve the problem because you do not have the setting for this (example in Arnold few year ago : i have added DOF on my scene. The DOF had noise. To remove noise, i had to oversample all (SSS, reflection, all...). Normally i had to oversample the AA, but the option was not here. Render time jump from 15min to 2h. I was few years ago, perhaps now this problem was fixed).
I prefer to see VRay with some "advanced" users than "no brain" users.

The solution would be to hide a lot of menu for "no brain" users, and keep an advanced mode.
In my current studio for the render setting we use the easy ways :
- subdivs mult to 0
- ADMC 1 - 10
- min shading rate to 10
- DMC adaptive amount to 0.9
No more, no less, work with 90% of scenes, and we do not need to tweak any materials/lights

If we have some noise, we set ADMC to 1-20. Another noise ? 1-30...
This is no brain, and it is working.

The only problems than we see with this settings is :
- IR map doesn't work with this. Perhaps you have to ignore IR map when subdivs mult is to 0.
- if we use DomeLight or DirtNode, we have more noise by default (with ADMC to 1-10). Perhaps you have to add more subdivs by default when subdivs mult is to 0 for DomeLight or DirtNode (and i think there is another nodes).

After this, why you do not add this "settings" for "no brain" users ?

Yeah the no irradiance map is kind of a drag

So bigbossfr you prefere to have global subdivs off? in some of my scenes I accidentally used this option and got surprisingly better render time! But as you said it does not work with irmap...so Kinda limiting.

[vlado]

So how do I go about getting the same look as when using adaptive?

You would generally keep the "Global DMC" noise threshold the same for both samplers (f.e. 0.005 or something like that); and then make sure that the progressive sampler "noise threshold" is the same as the adaptive sampler "color threshold" and that the min/max subdivs match. Here is a render done with progressive and adaptive samplers, along with the respective sample rate elements - you can see that render times and noise are similar.

Best regards,
Vlado

[vlado]

- IR map doesn't work with this. Perhaps you have to ignore IR map when subdivs mult is to 0.

Yeah, someone already requested that the subdivs==0 should not affect the irradiance map.

- if we use DomeLight or DirtNode, we have more noise by default (with ADMC to 1-10). Perhaps you have to add more subdivs by default when subdivs mult is to 0 for DomeLight or DirtNode (and i think there is another nodes).

For VRayDirt, this could work, yes. In hindsight, making the VRayDirt dependent on the AA subdivs was a big mistake as it caused a lot of trouble. Hopefully not too late to fix it

Best regards,
Vlado

[jasonhuang1115]

You would generally keep the "Global DMC" noise threshold the same for both samplers (f.e. 0.005 or something like that); and then make sure that the progressive sampler "noise threshold" is the same as the adaptive sampler "color threshold" and that the min/max subdivs match. Here is a render done with progressive and adaptive samplers, along with the respective sample rate elements - you can see that render times and noise are similar.

Best regards,
Vlado

Vlado, why the progressive sampler took longer to finish? The difference, if projected to a complex scene with longer render time, is quite big. Is it just about the progressive is relative new and still being optimized?

[thomaskc]

You would generally keep the "Global DMC" noise threshold the same for both samplers (f.e. 0.005 or something like that); and then make sure that the progressive sampler "noise threshold" is the same as the adaptive sampler "color threshold" and that the min/max subdivs match. Here is a render done with progressive and adaptive samplers, along with the respective sample rate elements - you can see that render times and noise are similar.

Best regards,
Vlado

Thanks for testing Vlado, I do believe you, it's more about understanding the settings, since especially the thresholds 0.1 up or down can make huuuge difference in quality and render time.

The solution would be to hide a lot of menu for "no brain" users, and keep an advanced mode.
In my current studio for the render setting we use the easy ways :
- subdivs mult to 0
- ADMC 1 - 10
- min shading rate to 10
- DMC adaptive amount to 0.9
No more, no less, work with 90% of scenes, and we do not need to tweak any materials/lights

So the global noise and the DMC noise are both put to 0.0 ? o.O

[vlado]

Vlado, why the progressive sampler took longer to finish?

Because of the intermediate image updates. Showing the intermediate image, and keeping something ready to show you at any moment, requires extra resources and CPU time. F.e. color mapping and gamma correction need to be performed for every update; this is a small thing but across many pixels it adds up. The adaptive sampler needs to do this just once after a bucket is complete; the progressive one needs to do it for every pass through the image (there were about 1600 of them for this render).

The difference, if projected to a complex scene with longer render time, is quite big.

This is not related to scene complexity at all. Only image-related properties have an effect on this (i.e. resolution, number of render elements and number of passes through the image). So for more complicated scenes, this additional time will be actually still the same and will be a smaller portion of the total render time.

Is it just about the progressive is relative new and still being optimized?

There are some optimizations that can be done for sure, but there is just a bit more work to do generally.

Best regards,
Vlado

[bigbossfr]

Yeah, someone already requested that the subdivs==0 should not affect the irradiance map.

For VRayDirt, this could work, yes. In hindsight, making the VRayDirt dependent on the AA subdivs was a big mistake as it caused a lot of trouble. Hopefully not too late to fix it

Best regards,
Vlado

IR map : yes, i think the fix can be quick (if 0 blabla). If you have some time for a nightly for this, just tell me.
This is never late to fix .

What about the DomeLight ?
I don't know why but by default with a domeLight we have a lot of noise. So, if i use the technique of subdivs mult to 0, all renderElement are ok (no noise in reflection. refraction, GI...) but the lighting render element has a lot of noise.
I have to add more AA max subdivs to have a clean result, but it looks like i will over sample other render elements (reflection, GI...) for nothing (because of the Domelight).
It is not possible to add more sample to domelight by default ?
Or perhaps do not affect domelight with subdivs mult to 0 ?

We are not far from an automated way...

[LudvikKoutny]

In Vray 3, universal settings finally work and they are finally optimal. By that I mean i am finally not getting better results if i am fiddling with all the settings myself. Currently, there are only 3 settings left that require human decision, based on scene type:

- Max AA samples
- Min shading rate
- Noise threshold of AA sampler (not the DMC one)

And of course, setting any subdiv value anywhere except IC and LC subdivs to 1. I always wish there was some option to completely ignore subdivs on all maps/materials/lights and globally override them with value of 1 so that i don't have to carefully check every asset brought from pre-3.0 scenes.

I think if all the other settings were gone, especially the entire DMC rollout, as well as subdiv values on maps/materials/lights, they Vray would gain bit more usability without any lack of flexibility.

It still requires some experience to determine right amount of ratio between Max AA samples, min shading rate and Noise threshold, depending on geometric, texture, or primary ray effects (DoF and MB) complexity of the scenes, but it's a lot easier to guesstimate than the hell there was in Vray 2.

I've already rendered lot's of various scenes, some of them super heavy, always using universal settings, and they never left me down.

[vlado]

I don't know why but by default with a domeLight we have a lot of noise.

Do you use it together with GI, or just the dome light?

Best regards,
Vlado

[vlado]

I always wish there was some option to completely ignore subdivs on all maps/materials/lights and globally override them with value of 1 so that i don't have to carefully check every asset brought from pre-3.0 scenes.

It's a bit non-obvious, but this is exactly what happens if the global subdivs multiplier is 0.0; except that we really don't want to do it for the irradiance map/light cache, which is what I will do for the next SP.

Best regards,
Vlado

[LudvikKoutny]

It's a bit non-obvious, but this is exactly what happens if the global subdivs multiplier is 0.0; except that we really don't want to do it for the irradiance map/light cache, which is what I will do for the next SP.

Best regards,
Vlado

Wow, thanks, that is good to know! For exteriors i use only BF as primary GI, and leave secondary to none, so i don't get in contact with LC nor IC.

[bigbossfr]

Do you use it together with GI, or just the dome light?

Best regards,
Vlado

DomeLight + BT GI generaly. Hum there is a difference without GI ?