Adaptive DMC and different render.

[ARTECONI-CGI]

Hi everyone,

I have a problem with the DMC. I am trying to render a scene in BF + LC. A sort of universal settings.
I have noticed that when I use min 1 max100 in general the image is darker or anyway notably different then when I use min 1 max 4. I will post an image when I can.
The difference in time is not big but I assume the 1-100 should be the correct one.
I would like to understand why do I get such difference in lighting.
Anyone can help?

I have already read the doc from Tony Bratincevic and altought it helps a lot I am still a little confused about it.

Kind Regards,

Giacomo.

[voltron7]

that is odd, I don't get that difference when I simply change the min and max sub values...
Sorry that's not a solution...

[Svetlozar Draganov]

Hello ARTECONI-CGI
Is it possible to attach this scene ?

[ARTECONI-CGI]

Hi Svetlozar,

how can I send you the file?

Thanks

Giaocomo.

[Dariusz Makowski (Dadal)]

It looks to me as if you unhided some lights inside the draw/changed shadow on matterials with glass or made the glass self illuminating. There is something more going on than sampler.

[ARTECONI-CGI]

It's lit just by vraylightmaterial

[Dariusz Makowski (Dadal)]

Yup but as you can see in the draw inside there is shadow or reflection changing or something. So maybe between tests you changed material or something. Or maybe u disabled ambient occlusion in GI.

[ARTECONI-CGI]

Not really.
It is exactly the same scene. I have just reopened the scene. Removed everything and render it over a new plane and I get the same result.
1-100 much darker than 1-4

Giacomo.

[ARTECONI-CGI]

The Difference you see in the draw and shelf is given by the sampling.
The Vraylightmaterial is mapped with a vraydirt (inverted) and its result is much more visible with 1-100.
When set to 1-4 it's blowing out.

Giacomo.

[Svetlozar Draganov]

Hi Svetlozar,

how can I send you the file?

Thanks

Giaocomo.

Please sent it to vray@chaosgroup.com

[joconnell]

Hmm - it kind of makes sense that it's darker at 1/100 - it might be a more correct light solution. 1/4 might not have enough samples to be able to deal with the blowout on your light material.

[Slazzo]

Had similar situation some time ago, I had subpixelmapping==on and higher AA would darken the image, while low AA gave me similar brightness as when subpixelmapping was off.

[lllab]

i think with subpixel mapping off is correct and/or the one with lower AA max,if subpixel is on and you have that high AA,the (unreal) effect of subpixel mapping will be multiplied more than with only 4x. so either turn off subpixel mapping or reduce AA max, (i have found AA around 32x is a good balance, fast and not so much negative effect if subpixelmapping in on)

[ARTECONI-CGI]

Hi all,

sorry for the late reply, I have been busy with some crazy deadline.
I'll try to send the file as things slow down a bit.

If I don't go wrong I have both the clamp and subpixel mapping on

Another problem I have noticed with the dmc is that sometimes raising the max subdivs increase the noise instead of clearing it.
I can't understand why this happen unconsistently.
I remember the thread from bertrand benoit and the article from tony bratincevic but to behonest I got lost at a certain point.
Is there anyone who has a simple answer to how exactly behave the dmc sampler on the latest vray versions and how to tune it?

Kind Regards,

Giacomo.

[Zdravko]

Is it possible to send us an example scene to support@chaosgroup.com?