creating a transparent shader with a non transparent print on..

[caligra]

I need help creating a shader;

Imagine a typical beer glass, in my case it is semi transparent with a tint of green and on the glass I have a painted label or a print that is not transparent. How would I go about creating that ?

My label/decal is a file texture

I have been struggling with the blend material but nothing really seems to go my way. Any ideas is welcome.

[pechart]

I usually don't do such things with layered shaders anymore. Most time it's much nicer just to put an aditional plane (or just duplicete the faces that need the texture) on the right place and make a seperate material for that. It's easier to control and you don't need to unwrap the whole model, just the labelplane. And you can just texture the alpha on that. Dunno if it's better in vray, but in mr it was really a pain to set up a proper working layered shader, especially if you're mixing mapped and projected textures. For me the seperate object way works best.

[Zdravko]

If your geometry is properly unwrapped you shouldn't have any problems to use the VRayBlendMtl to achieve the effect. Just set the glass shader in the Base slot, the print texture in the Coat Material 0 and a B&W image of the Label position according to the UV's of the object in the Blend amount slot.

[caligra]

Zdravko:
What I have been trying was to get the Alpha of my file texture to act like your BW image, but it didn't work well.. always some kind of minor blending even though the alpha is completely B/W.
I found another solution, using a normal Layered shader, with the vrayMTL glass as base and then a Blinn with the cutout label/print on top.. It renders, Albeit damn slow.

Pechart:
Yeah I have considering that, but this material is really a print on a transparent object and I would really prefer doing the shader like that.

Thanks for your input..

[Morbid Angel]

why not just separate the alpha as another bitmap? this always works correctly.

[caligra]

Its simply because all our textures are generated in another place, where the alpha is included in the file. This would mean that we will have to create new files form the original texture, just to do this - separating the Alpha from the texture file.. a bit annoying ..

So basicly I would rather use the info that is already included in the texture file, instead of using time in photoshop....