I have these two textures and I want that the red colored emissions will get left all other things get fully black that is everything except the red color in the images get left and others get fully black.enter image description here

enter image description here. .

I want to convert these textures like this enter image description here To this enter image description here

  • $\begingroup$ Your texture contains also baked emission lights, on other hand -reference texture is only source of light. Do you want to separate only source or all red baked in texture. For me it is hard to say what are only sources of light. $\endgroup$
    – vklidu
    Jun 5, 2021 at 16:26
  • $\begingroup$ Also ... Do you want to separate from texture or this is your model that you baked? Because if you have model before bake you can bake only Emission pass. $\endgroup$
    – vklidu
    Jun 5, 2021 at 16:28
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    $\begingroup$ Does this answer your question? Make specific color in a texture transparent $\endgroup$ Jun 5, 2021 at 16:54
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    $\begingroup$ @JachymMichal When I tried Gorgious (and yours) node tree it started to select white pixels before it handled whole range of red pixels (the same is visible on Sméagol image on greenscreen - it takes white skin pixels before green pixels on edge. Even with Robin's pointing to Lenght node and Luminance it still takes a lot of bright grey even a lot of dark red is there imgur.com/0k8mGQJ $\endgroup$
    – vklidu
    Jun 5, 2021 at 20:24
  • $\begingroup$ You're right, looks like having a more robust solution would be nice :). I've got some bounty points lying around, if you're interested... :D $\endgroup$ Jun 5, 2021 at 20:30

1 Answer 1


You can try ... directly Shader editor ... or Compositor that has more advanced Matte nodes and save Mask texture ... or any other image editor (application) that can select a color range.


Since you need red color ... I separated RGB channel and used G and B channel to Difference from R channel.

enter image description here

Since red color is contaminated by other colors (is blending to "metal" part of texture), you cant expect miracle ... but it can work kind of ...

enter image description here enter image description here

Green color for emission is used just to see how well matte (mask) served for separation.

  • $\begingroup$ Thanks for this great idea I don't know it ,but I want to know that how to remove everything except the red emissions with nodes or anything else. $\endgroup$
    – Avinas
    Jun 5, 2021 at 15:56
  • $\begingroup$ Check the output socket of RGB Curve node that is a mask for red color imgur.com/0SqERHw $\endgroup$
    – vklidu
    Jun 5, 2021 at 16:13

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