Reflection Glossiness and Vray Falloff

[MF_Danny]

Hello,

So I've noticed that when you add any map to the reflection glossiness input the Alpha of the map is automatically linked. Would I be correct in thinking this is because it only accepts a float value rather than a vector? When you hook up a vray falloff, it does just that, but the problem is that the alpha is just black and if you enable 'Alpha from RGB' it makes a bright blue (which yields a ref gloss value of 1.0). Now you can get around this by linking one of the RGB values to it... It's just a little annoying to add it and have to manually change the connection.

Another question on this, and forgive me I'm from Max so still getting used to the differences with Maya. Is Vray automatically producing an alpha from intensity when it hooks the alpha into the ref gloss (or other float inputs), as my maps definitely don't have an alpha?

Vray3.60.04
Maya 2018.3
MacOS10.13.6

Cheers,
Danny

[Morbid Angel]

In maya a color channel is expecting rgb(3 channels) and any value channel is expecting a single channel. When you connect a texture to glossienss for example it will automatically connect outAlpha of the file texture, but by default in maya alpha in the file node is trying to read the alpha channel of the texture which often is white or does not exist like in jpg. So there is a check box in file node called alpha is luminance which essentially will use rgb make it grey (single channel) and use the values of the rgb to drive the glosiness. You can also create a luminance node which flatten rgb to luminance and connect it that way.

[MF_Danny]

Morbid Angel - Sorry for the slow reply, thanks for your comment as well. Thought as much, I was just wondering if Vray automatically does the 'alpha is luminance' as I've never needed to enable it, even with jpegs (so no alpha channel there). Also the falloff node is annoying because you have to manually relink it... First world problems It's a shame Maya cannot do vector to float automatically oh well!