Grain Grain Grain

[vlado]

Well, Adaptive subdivision with Min/Max rate 0/2 is the closest to the old Two-level sampler; in images with large smooth areas without detail, it will be faster than the Adaptive QMC sampler.

Best regards,
Vlado

[yeeha68]

Yes, I have found that in an animation Adaptive Sub does not provide the detail needed..thin parking lines, and thin details flicker on and off.

...So that goes back to my original question...What happened to Simple-Two level? Adaptive QMC does not seem like a better solution.

[vlado]

Well, the two-level method had its issues too... it could get very slow when you have lots of details that need supersampling - sometimes even slower than the fixed sampler. The adaptive qmc method is somewhat more reliable in that regard, with less variation of render times.

The great advantage of the adaptive qmc sampler is that it is highly adaptive - i.e. takes a different amount of samples based on the desired noise level. Basically, it does something very similar to the path tracing mode of the Light cache, but on a bucket level, with varying amount of samples. This can be very useful for high quality images. For example, you can set the the Fine subdivs to a high value - like 100, and forget entirely about Subdivs in lights, materials, direct GI, moblur, DOF etc. You just use the Noise threshold to set the desired image quality - something that you couldn't do with the two-level sampler.

Best regards,
Vlado

[flipside]

Vlado, does that mean that when you set min samples in qmc roullout to for example 40, and you have all materials and lights with for example 8 samples, that all these will be given 40 samples instead of the 8?

[vlado]

Vlado, does that mean that when you set min samples in qmc roullout to for example 40, and you have all materials and lights with for example 8 samples, that all these will be given 40 samples instead of the 8?

No; the Min samples parameter in the QMC sampler rollout will not increase samples beyond the value specified by the user (which is 8 x 8 = 64 for 8 subdivs).

However, if you have, for example, fixed AA with 40 subdivs, that will cause all materials and lights to use at least 40 sudivs too. Adaptive QMC aa however may take less than those 40 subdivs, depending on the noise you get.

Best regards,
Vlado

[themaxxer]

For example, you can set the the Fine subdivs to a high value - like 100

vlado what do you mean with "fine" max. or min. subdivs?

best regrads
themaxxer

[s7en]

I for one would also love to see simple two-level antialiaing put back in the current vray - as a fourth AA ooption, not as a replacement to QMC. I too have never been able to get QMC antialiasing to match the same level speed-for-quality that two level in 1.09 gives me. Which probably explains why I still use 'old reliable' 1.09 rather than 1.47 for most work.

Sure, simple two-level can take longer to render if you get the settings wrong, as Vlado once said, but if you do it right, in my experience, it can produce more optimised results than QMC. I for one miss its flexibility.

Vlado, what are the chances of it making a 'comeback special'?