Textures with alpha/transparency channel and VRayMTl

[snivlem]

A little embarrassing not knowing this but recently started having to do some texture work.

How does one use a single texture to drive both the opacity and diffuse of a VRayMtl?

Obviously for diffuse its:

file.outColor -> VRayMtl.color

but whenever I use file.outTransparency or file.outTransparencyR or or file.outOpacity Opacity never appears as an option to connect to in the Node Editor?

Is there a way to do this?

[francomanko]

if you have an image with an alpha channel you can map the outAlpha to the RGB channels of VrayMtl opacity.

[snivlem]

THanks - it looks like one has to do this connection manually 3x as Opacity is split into rgb which was throwing me off. Sometimes too opacity didn't appear for me.

[snivlem]

Okay so not going crazy after all there are two issues.

1) Opacity doesn't appear on the list if you are using a scene that was perhaps built with an older version of V-Ray. Create a new VRayMtl and Opacity will appear so we can connect to it
2) TIFF opacity doesn't work at all (alpha channels are completely reversed) however when saving as a PNG, the exact same file the alpha channel works as expected.

So with those two things it's no wonder why it didn't make sense how I could get alpha working!

[thescopeteam]

yeah, this was 2016 and in 2020 its the same great feature, thank you Autodesk