Alpha channel use in gimp (paint on it)

[majorfatal]

Hello,
I'm beginner to the gimp and come from photoshop.

I'll would like to know how change the color of the alpha channel.

I"ll would like to paste a color into or paint on it.

How I'll could do it?

In photoshop it was simple I'll make an image in grey >ctrl C >ctrl v in alpha channel.

Ill would like to do the same but it seems impossible to edit the alpha!

I'll work mainly in video game and need to use Alpha channel.

In fact I'll don't care there is an alpha on alpha channel I'll just want to copy a grey image on it.

Thanks by advance for your help.

[rich2005]

I think this question has come up before from PS refugees.
As far as I know it is not possible to use the alpha channel for other than what it is meant to be used for, ie. as a transparency mask.

This an image with an alpha channel and a layer mask added. Paint in the layer mask (or copy / paste from elsewhere) and that is applied to the alpha-channel.

   

[dinasset]

@majorfatal

I think that what you are planning could be realized by:
- add a mask to the layer choosing "gray copy mask"
Give it a try.

[Ofnuts]

(02-08-2021, 10:47 AM)majorfatal Wrote: Hello,
I'm beginner to the gimp and come from photoshop.

I'll would like to know how change the color of the alpha channel.

I"ll would like to paste a color into or paint on it.

How I'll could do it?

In photoshop it was simple I'll make an image in grey >ctrl C >ctrl v in alpha channel.

Ill would like to do the same but it seems impossible to edit the alpha!

I'll work mainly in video game and need to use Alpha channel.

In fact I'll don't care there is an alpha on alpha channel I'll just want to copy a grey image on it.

Thanks by advance for your help.

To edit the alpha of a layer you just add a layer mask, and then "paint the alpha" on that mask.

A nice tutorial: https://patdavid.net/2011/10/getting-aro...masks.html

[majorfatal]

Thanks for the responses,

I'm going to try theses methods. Yes I'll the gimp is a great soft but I'll come from PS and it's hard to find the automatism thant I had.

Thank for all.