How to put masks in each color channels?

Hi all!

How to get those masks in their corresponding channels using GIMP is what I need to know.

See the other images below the nodes image to see how each color channel shows a different set of painted shapes.

Thanks in advance guys :slight_smile:

https://docs.unrealengine.com/latest/images/Engine/Rendering/Materials/HowTo/Masking/TM_Chair_Material.jpg

Check the PNG that contains them all here http://gimpforums.co…nt.php?aid=5043
Originally it was a TGA

Thanks to Ofnuts from gimpforums.com
Colors>Components>Decompose will decompose an RGB image into 3 greyscale layers for R, G, and B.
Colors>Components>Recompose to go the opposite way after editing these layers

I just paste selections from one document’s rgb into the desired r, g or b channel of another.

From one document to another?
I tried copying from another channel and the regular RGB layer but instead of into the channel I need it to, but it shows as black instead of green.
Would you mind elaborating just enough so that I can get it done? I’ll appreciate every detail :slight_smile:

DPC

Sure!

-Create a regular RGB document. It has to match the the size of the target document, i.e. 2048 and 2048.

-Create 3 layers. For the sake of the tutorial name them identical to the channel you will be transferring them to, so red, green, blue.

-In each layer, you will create your mask. Be sure to fill the mask with pure white.

-Ctrl + Click your layer’s icon to grab the selection (Be sure your layer is still selected, or else it won’t work) and Ctrl + C to copy.

-Go into your target mask document. This should be the same size as your original document, and should have a black background. Go over to the channels tab and select the red channel, go to edit > paste > paste in place. It should paste it exactly where it belongs in your new document, and isolate it to the red channel.

-Repeat these steps for Green and Blue. You can also create an alpha channel to store a 4th mask.

-When you are finished, select RGB to view the image as a whole and it should be a mixture of colors. Save the final composition, and then plug in those values in UE4.

Let me know if you need any more clarification. =)

Excellent!
Thanks a lot for this tutorial SE_JonF, I’ll give it a go asap. But for the looks of it I should have no problem :wink:

DPC

No problem, good luck! =)

there’s an easier way and you only have to do it once

  • make a group (folder) for everything that will go into the Red channel, and then the first layer inside the group should be a new layer filled with pure red color, layer set to Multiply
  • on top, make a group (folder) for everything that will go into the Green channel, and then the first layer inside the group should be a new layer filled with pure green color, layer set to Multiply. then set the whole group to Linear Dodge
  • on top, make a group (folder) for everything that will go into the Blue channel, and then the first layer inside the group should be a new layer filled with pure blue color, layer set to Multiply. then set the whole group to Linear Dodge
  • enjoy not having to make some annoying procedure every time you want to make changes and save
  • profit

Thanks a bunch Chosker, it sounds great! I’ll have to wait until I have the chance to try it, but I can hardly wait :wink:

DPC

SE_JonF, I finally got a couple minutes to try this…
To be sure we’re on the same page… When you say “…In each layer, you will create your mask.” Do you mean to select “Add Layer Mask” from the contextual menu when right-clicking on the layer?
Also, “Ctrl + Click your layer’s icon to grab the selection…”
032e3785fa2fc2b2fca48b4039b3a4ea0a595a1f.jpeg
If I got it right, nothing happens when I Ctrl click that icon :frowning: Is this to select the part I want to mask? If so, could I just use the magic wand or any other selecting method?
If I have understood the premise of how this works, am I to copy the parts I need to mask from the original document (on the left-down) to the new document with 3 layers (right-up)?
making_masks.JPG
If so, at the moment those 3 layers are empty but eventually I’ll paste those selections from the original to their corresponding layers, each pasting I do will be filled with white. Did I get this?

Thanks SE_JonF in advance :slight_smile:

No, when I say create a mask I mean the image contained in the layer. Whatever you want your masks confinement to be, just create it in that layer and make sure it is colored white. Do not add a layer mask, for the purpose of photoshop you are just creating a normal 3 layered image.

So basically I create a layer in an RGB document and call it RED. I will then create a rectangle in that layer along the top edge of the document that is colored white.

I then create a layer and call it GREEN. I create a similar white rectangle in this layer, except this one is placed along the bottom of the document.

Now Ctrl + click the square to the left of the layer name and it should grab the selection of your specific layer. Be sure that you have this layer selected as well, because if you do not you cannot copy the empty space from another layer.

Repeat the same for the blue layer.

Let me know if you need me to clear it up any further. It’s really simple once you get the idea of it. =)

Also, if the image you have above is your mask - be sure that the dark spots are cut out of the light tan mask otherwise it will overlap in UE4.