different AA threshold in one render?

[Komposer]

hi,
is is possible to render with 2 or more different threshold settings in one render step?
As example.
I´ve a ball swimming in water.
The ball needs more samples (1, 15, 0.01) than the water (1, 15, 0.03), but I will render it in one step.
I hope for a yes
I know how to do that with render layers, but in this case I´ll avoid that procedure.
Thanks, Jörg

[vlado]

It is not possible right now, unfortunately. We've been keeping this on the "to do" list for a long time... You can can control the shading samples per object using the sampling multiplier in the V-Ray object properties though - I don't know if this is helpful.

Best regards,
Vlado

[Komposer]

Thanks Vlado for your fast answers
I made a test with the vrayproperties attribute and found a strange thing here:
the images shows the rendering and the rendertime with and without probs enabled.
with probs disabled the render needs 2:47
with probs enabled it needs 3:55
WOW...
it´s a more or less simple plane with displace and bump and one HDRI for ref...
If the Subdivs Mult helps on the AA theme I can´t say it in this moment.
Did You mean this Subdiv Mult in your answer? For me it looks more than a Mult for GI only!?
Thanks, Jörg

[Komposer]

now I red you answer again and I´m sure, that I can´t find the "sampling multiplier" in Obj properties...
"You can can control the shading samples per object using the sampling multiplier in the V-Ray object properties though"

[vlado]

It's the "subdivs multiplier" parameter. Obviously it only works for glossy effects, GI etc, it won't have any effect if you have clear reflections.

Best regards,
Vlado

[Komposer]

hmmm..thanks Vlado...
And what do you say to the much longer rendertime, using object properties as shown below?
Thanks

[vlado]

It's normal for the object properties to have some overhead; I'm not sure how much that would be - we should probably spend some time to profile it.

Best regards,
Vlado

[Mihail.Djurev]

There is a slowdown when using object properties, but it shouldn't be that dramatic. I made a scene similar to yours and the slowdown is about 5% at most. Could you send your scene to support@chaosgroup.com with a link to this thread so we can see what's going on?

[Komposer]

thanks Mihail,
I tried to repeat the situation and couldn´t confirm what happens here a few days before.
The ca. 5% is what I see.
I will hold it in mind, and if I come again into this situation, I´ll check it again.
Cheers, Jörg

[Morbid Angel]

When you are dealing with pure reflection like that, where you only have hdr and reflection subdivs, its only the aa or the local subdivs which will make a difference.

In that case, I would suggest not to use glossy reflection since you most likely can get away with mirror like water reflection (it will speed up the render time some what) I did a shot recently with a lake with very similar setting. Only using local subdivs gave me a clean image without going too crazy into render time.