Foliage/Trees slower with Opacity set to Clip ???

[baumgore]

Getting weird render times here. Clip mode is a lot slower then normal mode with a forest full of trees with opacity-foliage.
Shouldn't it be faster? Is Normal mode the true Clip mode?
And both renderings looks exactly the same.
Adaptive AA. BF/LC GI.
VR 3.10.01 x64 Max 2014 here.

[vlado]

I can't reproduce that here; the clip mode has always been way faster than the normal for me. If you have a scene where it isn't, please send it to support@chaosgroup.com so that we can check what's going on.

Best regards,
Vlado

[Dman3d]

I have noticed the same issue. I was fairly excited to see the demo.
Vlado, did anyone send you a file yet to test?

[vlado]

Vlado, did anyone send you a file yet to test?

Nope.

Best regards,
Vlado

[Dman3d]

Ok I will see if I can isolate the problem into a smaller file to send over.

[m_hinks]

Anything come of this?

[vlado]

Nope. No-one got me anything and in my tests, clip opacity always wins.

Best regards,
Vlado

[m_hinks]

Seems most suppliers of trees, such as Laubwerks are now making their mats with filtering off, and pretty black/white alphas, so I guess these new methods will not help as they are already "optimized".

[vlado]

Filtering off may not be a very good idea as it makes the trees way more prone to AA flickering in the distance.

Best regards,
Vlado

[m_hinks]

Ok, so maybe leave the filtering on/turn it on to Pyramidal but use one of the two new methods.

[vlado]

Ok, so maybe leave the filtering on/turn it on to Pyramidal but use one of the two new methods.

Generally, filtering on with stochastic opacity is the best tradeoff between quality and speed. Clip opacity and filtering off might be faster, but will create more work for the AA sampler.

Best regards,
Vlado

[m_hinks]

Ok, I'll send Laubwerks an email, maybe their next update can have the filtering back on for all opacity maps, even set the mode to Stochastic as well.

[timm.dapper]

Hi there,

our experience in the past was that switching filtering off produced fewer middle-tones in the alpha and therefore was faster. We had cases in which this change cut render times in half for vegetation-heavy scenes.

I am not sure I'm aware of a Clip option. Can any of you please elaborate? Is that a new option? If so, which version of V-Ray was that introduced with and what is the exact technical background? Is there a link to the respective chapter of the documentation any of you could provide?

Best
Timm

[Vizioen]

Hi there,

our experience in the past was that switching filtering off produced fewer middle-tones in the alpha and therefore was faster. We had cases in which this change cut render times in half for vegetation-heavy scenes.

I am not sure I'm aware of a Clip option. Can any of you please elaborate? Is that a new option? If so, which version of V-Ray was that introduced with and what is the exact technical background? Is there a link to the respective chapter of the documentation any of you could provide?

Best
Timm

http://docs.chaosgroup.com/display/VRAY3/VRayMtl# Scroll down to opacity mode under options.

[vlado]

There is some more information here:
http://docs.chaosgroup.com/display/V...ymodeparameter

Best regards,
Vlado