Threshold_issues

[Nachex]

Hi my friends, I've been having several issues or doubts about the threshold function of the image sampler, dmc threshold and the subpixel mapping.

Currently, in other vray versions, in the DMC adaptative you have clr threshold and nrm threshold, but in vrayblender you have only Use DMC sampler threshold.
So my doubt is check the "use DMC sample threshold" you are overriding nrm and color thresh. Because I'm currently having problem of getting rid of little noises in bright areas. I other vrays with 0.01 or 0.05 in the DMC threshold you don't get that amount of noise like in this version, to get rid of that noise in bright areas i have to go up with threshold 0.002 and increases rendering time a lot.

It's only threshold problem, no matter if you have GI, materials or light subdivisions.

And my other doubt i have is a strange behavior with lights in some parts of geometry like in the image attach, I have an area light with no directional or texture, and I get a lot of roughness in the hat of the character, it's just a vray material diffuse, no glossy, spec or reflection maps.

any ideas?

Thanks !

[Neilg]

That looks like vrays sampler isn't working at the correct gamma, those borders of noise are something you see when 2.2 isnt set up right.

[Nachex]

Understood, I'll try at different gammas and color mapping settings, still happens the same. I try rendering the same geometry in vray for max, with the same DMC and again different gammas, and didn't happen the same. I'm sure i'm making some mistake in a parameter :P

[andybot_cg]

And my other doubt i have is a strange behavior with lights in some parts of geometry like in the image attach, I have an area light with no directional or texture, and I get a lot of roughness in the hat of the character, it's just a vray material diffuse, no glossy, spec or reflection maps.

Looks like a problem with your irradiance map. Check your interpolation settings, make sure they are high enough (I'm assuming you're doing animation.)

[Nachex]

Yeap, Well low IM it's quite particular it gives you splotches no noise problems like this. My issue is not even because of GI, lights or material subdivision. I'll keep looking and let you know what could be my mistake or problem

[Neilg]

render out elements - look at the reflection element, or lighting element or whatever and find out where the noise is coming from.

[Nachex]

I found the solution!!!! I turn out gi, reflection and glossy. Then unchecked Use global settings in the lights and voilá!
Life isn't that bad after all.

No more peppermint noise.

[andybot_cg]

ah, too funny, I thought the tortoiseshell texture on the glasses frame was irrmap splotches...

Glad you figured out about the lights. Good to know.

[Nachex]

Yeap, main problem is Cutoff threshold of lights, can make weird artifacts in noise, just beware of lights if you have that problem, the rest vray is magic