QMC sampler question

[swisscad]

Hi everyone
is the QMC subdiv multiplier the same as the global subdiv multiplier in max?
ie: does it multiply all subdivs....

Thanks

[dalomar_cg]

Re: QMC sampler question

Jennifer,

Yes it is the same, but no it doesn't apply to ALL multipliers...From Spot3d

Global subdivs multiplier - this will multiply all subdivs values everywhere during rendering; you can use this to quickly increase/decrease sampling quality everywhere. This affects everything, except for the lightmap, photon map, caustics and aa subdivs. Everything else (dof, moblur, irradiance map, brute-force GI, area lights, area shadows, glossy reflections/refractions) is affected by this parameter.

So essentially, every thing that doesn't have some sort of photon/path-tracing at the heart of its calculations and AA.

Personally, I tend to leave this value at 1 for two reasons... First is that it applies to almost everything, and second that it increases everything the same. The first one is an issue for me because rarely do I see an issue where all of the possible subdivisions need to be increased. Usually I can get away with increasing a few key settings and that does if for me...one of those is AA subDs, so using the multiplier won't help with that anyway. As for the second reason, even if it is deemed that all of these subD values need to be increased, I would doubt that they would all need to be increased by the same proportional amount...ie if I set the multiplier to 1.5, for IR that will lead to a value of 75 (assuming the default of 50 subDs) which may certainly be enough. Material glossiness values, however, will only be increased to a value of 12 (assuming the default value of 8 ) which may not be enough to sufficiently smooth things out. Essentially, I think that using this value has a tendency to slow things down more than is truely needed.

The few instances where I would recommend using this value is when you've got a scene with final settings that you don't want to mess up. Then decreasing the subD multiplier is a good way to do tests with out "altering" those final settings.

Just my 2 cents on the issue.

[swisscad]

Re: QMC sampler question

Thank you very much 2 pennies for your thoughts anytime! ;D