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I would like to make a decal in Cycles.

When I use Clip in the Image Texture Node then the background is black. I would like it to be transparent.

The manual (https://docs.blender.org/manual/en/dev/render/cycles/nodes/types/textures/image.html) says: Clip "Clip to the original image size and set all the exterior pixels values to transparent black."

What the hell is transparent black? Is it black or is it transparent? How do I get the background image to show through the "transparent" black?

This is my setting: enter image description here

enter image description here

Maxx, like this? That makes the Logo Black. The Image has no alpha information.

enter image description here

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A color has for components : red, green, blue, and alpha. Transparent black would be 0,0,0,0. The image texture node outputs red, green, blue in the first (yellow) output and the alpha in the second (gray) output.

If you want your surface in cycles to be transparent where alpha is less than 1, combine a transparent shader with your current shader with a mix shader node, and use alpha as the factor. (current shader in the second input, transparent shader in the first input).

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  • $\begingroup$ But it is just a square logo. It has no alpha and it should not need one. I just do not want to tile it and have the background be visible behind it. $\endgroup$ – Coffeehouse Nov 7 '17 at 8:36
  • $\begingroup$ The alpha outside of the image is generated by the Clip option : "set all the exterior pixels values to transparent black". $\endgroup$ – Maxx Nov 7 '17 at 9:22
  • $\begingroup$ That's why your last try works ! You replaced the transparent shader with your background image, and the mix shader with mix RGB but it is kind of the same solution :-) I thought your background image was on a seperate object behind. $\endgroup$ – Maxx Nov 7 '17 at 9:33
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I did not get it to work with the transparency shader but it seems to work when I just attach the Alpha of the Logo (although it has no alpha channel, I believe - it is just a jpg) to the Fac of the Color Mix Node.

enter image description here

enter image description here

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