Label on a Bottle - Problem with Alpha

[Dim Vilain Greens]

Hi.

 

I have a problem that I just can't solve, so I'm hoping that someone can help me out.

It seems to be simple, but Houdini is still very new to me.

 

So, I have a model:

 

 

I want to apply a label to this model.

The label is a .png file with an alpha channel, so that it would only show that and nothing else.

 

Using a UV Quickshade node, this works as expected:

 

 

However, when using a Mantra Surface with the same texture applied as a color map, the whole model is visible:

 

 

My goal is simply to have different materials for the body and the label, so that I can shade them independently.

Maybe this approach is not very good in the first place...

 

Any help is much appreciated.

[gui]

the surface model, by default only uses the rgb of the texture (not the alpha).

Just save a black and white image with alpha and use it the opacity map (I don´t think It will use just the alpha of the original image).

 

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sorry, but on second thought, that won´t work (the rest of the geo will be transparent). I will post a file in a sec

Edited June 23, 2014 by gui

[gui]

Here it is. I had to manipulate some things in the default surface shader, to add one more layer of texture.

Just look inside the shader, and you will see an yellow box with the changes.

Inside the "img" network you will find the map I used.

two_textures.hip

[Dim Vilain Greens]

Thank you so much for your solution.

This is more than I could have asked for.

 

The method with opacity map works for me too. Just needed to create actual geometry for the label and apply the material to that.

 

Thanks again.