Photoshop not saving Alpha channel?

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13 comments, last by leiavoia 19 years, 6 months ago
I'm running Photoshop 6.0.1, and despite having a texture with transparency in it, when I save it as a TGA it does not save the transparency. Does anyone have a solution for this?.
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How are you creating your alpha channel? AFAIK it doesn't work properly unless you paint your transparency as a mask. From there, you're free to save it as a TGA and keep the transparency. Painting an alpha channel will not work. I don't know why.
Quote:Original post by evolutional
How are you creating your alpha channel? AFAIK it doesn't work properly unless you paint your transparency as a mask. From there, you're free to save it as a TGA and keep the transparency. Painting an alpha channel will not work. I don't know why.


Ugh, Interesting.

Thanks I'll try it as a mask.
thats odd, the TGA alpha bug is a 7.0 bug.. AFAIK my 6.0 install works as it should.

Check Adobe's website, they have a patch for it on their website
mybe they will have a 6.xx patch too?
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Yeah, usually this is a 7 issue. You are saving it as 32bit, right? ;) Just making sure.
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Isn't this bloody thing in the FAQ yet ?

You have to be careful that you have an Alpha channel, if you want your transparency to be taken into account when you are saving.
Just because your layer isn't totally covered with opaque pixels (if you start painting on a new layer with an translucent brush, for instance) doesnt mean anything to Photoshop.
What you need to do is to select all pixels (Ctrl clicking on the Layer works fine for me) then create a mask from this. Not a Layer Mask, mind you, but a stand alone mask. Because a Mask will be stored as a new Channel, and that's exactly what you want.
If you store the file as a PNG, for instance, it works perfect.
(I never use TGA, so I wouldn't be aware of that bug they refer to, but I am pretty sure my instructions should work. Feel free to ask again, if need be)
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he is probably trying the photoshop 7 method of making alpha using transparency :) instead of creating a seperate channel. Its not a bug as far as I know in 7, adobe did it to meet targas standard?
I noticed painter took out alpha channels on tga just before.

I have no idea if the new way works on sub v7.

Personally if I have to use 7, I prefer to use channels and save
it using the tga plugin you can download from all over the net.
Wow. This explains a lot. Thanks, ahw. Why couldn't the damn program just make your empty, transparent area... transparent!? Well, I mean, I guess I can see why, but still, it seems a little counter-intuitive. This should save a LOT of time when I'm video editing because I won't keep having to hack the dumb transparency in Premiere.
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You may find it counter-intuitive, but when working on critical game artwork its a big advantage to keep your alpha channel visually in black and white 8bit channel. It is also logical if you are visualising a 32bit image made from RGBA, you expect the A to be a seperate channel. Also alpha channels are not just used for transparency, for instance you might have a normal map in RGB and a specular map in the Alpha channel.

As soon as you upgrade to 7.0 you will get transparency as you expect, its just everyone who has been using alpha channels for years will be downloading the plugin so they can revert to the old method :)
Tell me about it :)
It took me some time to figure out, but once you understand it, it's rather logical.
The trick is to know how to use Masks and if you want to kmnow a "What I see is what I get" way of doing it you just Duplicate your image, Flatten it, and Ctrl Click on it then create your transparency Channel from that selection (coz transparent pixels _will_ be transparent and alpha values kept).

That's the way I do it anyway, saves me a lot of headaches :-P
Imagine how happy I was when I realised I could actually use my alpha layer in Director rather than shitty GIF transparency !
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