Forums Technical Discussion PBR and Shader with Alpha Channel

PBR and Shader with Alpha Channel

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winkel
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Hi,
maybe this is a stupid question, but I cant find a shader where I can use a alpha Channel from a picture to make things transparent. I dive intro a “material shader builder” and can change the surface alpha to produce a alpha channel but I can't see objects behind. I've tried to add the picture to BSDF… but how?

Thanks
Detlef

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PBR.jpg (89.6 KB)

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old_school
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You need to modify opacity. Opacity is used for primary sample transparency.

Alpha is used in raytracing and also to dump out an alpha channel in the final rendered image.
There's at least one school like the old school!
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winkel
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but that was the first I've done…. a opacity Map with no results. I took a TGA-file with an Apha Channel - wrong?
Detlef
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Mario Marengo
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winkel
but that was the first I've done…. a opacity Map with no results. I took a TGA-file with an Apha Channel - wrong?
Detlef

No; not wrong *if* you used the map's alpha channel to define the opacity ouput (Of). But you have to actually tell the shader to do that (a Texture VOP won't do it automatically for you, for example).
But setting opacity (Of) – whether from a map's alpha channel or somewhere else – is definitely the right thing to do.

Attachments:
test1.jpg (168.1 KB)
opacitytest1.hip (774.0 KB)

Mario Marengo
Senior Developer at Folks VFX [folksvfx.com] in Toronto, Canada.
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winkel
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Thanks I never give up to learn;o)
Detlef
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