Today I installed Vray 3.3 (3.30.04) for the first time. coming from Vray 3.2. I´m currently testing all the feature before switching completely. I´m running into various problem whens I turn on “Clamp Output” (wich I use frequently) . It seems to happen especially with adaptive AA. I have a fresh scene lit by a Vraylight and a VraySky. Settings are pretty much out of the box.
This is the image rendered without clamping on the left and with clamping on the right
The first obvious difference is a much stronger noise (while it also renders much faster). The noise get´s even stranger when I turn down the color threshold of Adaptive Sampler
The noise get´s less when I turn up the min subdivisions of the adaptive sampler. In previous Vray versions you could have turned clamp output on a render with min/max settings of
1/x pretty much noise free. That wouldn´t really be the problem as it still renders quite fast even with min subdivs larger that 1. But as soon I have min values of 2 or higher the max value is
completely ignored. I get the exact same render time and image quality when I have a setting of min/max 4/24 compared to 4/10 or even 4/100. No difference.
Also there is a second problem. When you look at the unclamped and clamped image notice the blue from the sky is neary gone in the clamped image. The bleeding on the wall as well as the reflection on the floor is gone. When clamping is on I need to turn off divide shading subdivison as well as tunring on use local subdivisons for the blue to come back.
It does look like a bug. What are your color mapping settings? I’m (almost) ready to swear that tested all combinations that I could think of, but maybe I missed something.
my Reinhard color settings are multiplier 0.6 burn value 0.3. I attached the scene (max2014). The pictures from yesterday were rendered with a standard camera. I now also included a Vray camera just to make sure it´s not the camera.
It´s a bit better but it the problems still occur. With a Vray Camera the noise problem only happens when a. the Multiplier/Burnvalue is not 1. and b. it get´s worse as brighter the image/smaller the f-number is. The blue color bleeding from the sky also is gone with a VrayCamera as soon as clamp is on no matter what reinhard settings. Also leaving the settings at 1/1 doesn´t change this. Once clamp is on the only way to get the bleeding back is turning off “divide shading subdivs” and activating “use local subdivs” (both must be set). Also as soon as you open the scene try to set the min subdivs of the aa to something like 4. After that the max value can be set to anything bigger than 5 and it makes no difference. Vray_33004_color_clamp.zip (30.3 KB)
I’ve tested your scene with 3.2 and got the same amount of noise, can you try it ? (just changed the sky model to Preetham, since Hosek is not supported in 3.2)
Sorry I forgot to mention.
In Vray 3.2. Set mode to “color mapping and gamma” while setting gamma to 1 (wich should result in the same image as with mode color mapping only) and the noise is gone. In Vray 3.3 this doesn´t seem to work anymore. This is how I had color mapping by default in my maxstart.max.
