Alpha output not completely black and white

[marksmanguy]

I've been having problems for a while with saved alphas. To the naked eye they seem like they are completely black and white but they in fact aren't, and become very apparent at times when used as masks in Photoshop.

Anyone else experience this as well?

Thanks

[hristo.dimitrov]

Please send us to support@chaosgroup.com your scene along with all assets used in, for investigation.
We will also need information on the version of the 3dsMax that you are using and the version of V-Ray.
Also if it is possible to explain to us in detail what is your workflow.

[marksmanguy]

Hi Hristo, thanks for the reply.

It is not scene specific. Every project I do, I need to adjust the alpha in photoshop to be 100% black and white. Attached is an example of what the alpha looks like when levels are pulled up to it's extreme. There are slight color values as well.

I'm using 3ds Max 2017, Vray Next latest version

Is it a problem with using the Vray Buffer exposure sliders?

Thanks

[marksmanguy]

I tested with all of the correction controls off and still the same result.

[marksmanguy]

This happens both on CPU and GPU. When looking at the levels of the alpha, it is not 100% pure black and white.

[marksmanguy]

It is strange that it happens with only certain scenes. I am going to go through my projects and send the ones that seem to have this issue. Attached is another example of what the alpha channel looks like when levels are pulled up. These subtleties are sometimes noticeable when making changes to something in a masked area, and it slightly affects the area that is supposed to be masked off.

[secondplace]

did this get resolved? we are having the same problem.
the alpha is around 0.96 and it changes every render between 0.95 and 0.98
this also happens on a new scene with only a box. if we render it in max 2018 it works but if we save the file down to max 2016 and render the scene again in max2016 the alpha is not 1.0 anymore.
we do have the point in vray framebuffer history where it started but we cannot figure out what could have possibly broken 3dsmax 2016 with vray 3.6 from one render to the next.

[nickolay411]

Bumping this thread. Same thing is happening in 3dsmax and maya for us. Turning off gi and then all global switches like lighting, shadows, gi, reflections, glossy has no effect. Alpha pixels are popping up around .95-98 for us too. Last tested on Vray 5 for maya update 2.3. Seems like vray render engine issue.

[dimitar_panayotov]

nickolay411, could you please send a simple scene through our support contact form?