AuthorTopic: Set different opacity for different pixels in GraphicsGale  (Read 2598 times)

Offline wanderer123

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So I've been trying to do this for literally an hour or more and I still can't do it. I am trying to have different opacity for different pixels. I know the alpha in the RGB does it but it doesn't work. If I were to create a blank image and do make alpha channel, it works. But I can't do it on an already existing image and I can't create a new image, make alpha channel and paste another image to it. Sometimes even the pixels won't be put on it, I don't know why that is. It's so frustrating! Please help me out!!

Offline Conzeit

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Re: Set different opacity for different pixels in GraphicsGale

Reply #1 on: November 11, 2017, 03:20:05 am
PixelPiledriver is far more comfortable with this kind of thing than I am but I can tell you of a way to do this.

the alpha channel is a wholly different invisible image in your file, much like in photoshop. The way I handle it is by  going to

image/make alpha channel/
create from:luminance

then you'll see how roughly you have dark things transparent and lighter things fully visible.
this is somewhat useful but probably not what you want so go to

image/duplicate alpha channel/

now you'll get a wholly new image in grayscale that you can edit, it'll be called image1.png or some number like that. On this image black is invisible white is visible. Personally at this point I load an under 16 color pallete I have prepared because it's most useful for effects, which is what I tend to do with this, and edit it with that. whatever you do works as long as it's still a scale of greys.

once you think you're happy with your alpha map, go back to the original image and go to make alpha channel again, but this time make the source that new image that was generated

image/make alpha channel/
create from:luminance

then you can see how the alpha actually shows up on your image and edit accordingly.

I think pixelart programs should be better about editing alpha channels while using grayscale palletes, and NOT modifying the regular pixels but this is not the case. if you have Promotion it also supports alpha channels but it's awkward in different ways. I usually use a mix of both ggale and promotion