Transparency and Alpha Channels: The Definitive Guide

OK, sorry, as far as the new raster I mean creating a new file... When ever I followed the steps step by step, loading the alpha file from the group like I have tried to do so many times over the past month, I have not been able to get the actual alpha to load correctly...


AS far as the Transparency on mine, I have doubled back 4 times on one image I am testing out, have tried a variety of dark grey to as black as I could get, and I must have been going cross eyed with getting it because I just did it again right now checking my work and it worked!! Thanks chosen.. And sorry for not explaining the earlier better... I hve just spent a month of decoding tutorials for psp... and that is just way I have found it easier was by creating the mask and saving it then starting a new file, and on the raster for that file, coloring it the texture u want to chose and then doing alpha that way, cause before I couldn't get it to work, always have the solid white tee shirt underneath the trans never came out right

Glad you got it worked out, Jasmin.

And thanks for the clarification on the multiple files thing. Personally, I wouldn't choose to work that way, but if you're comfortable with it, great. Thanks for sharing your technique. It can only help for people to see multiple ways of doing things.

so i've been using alpha channels in the gimp and i think it is very similar to photoshop.
i've been using the layered templates and basically what you need to do is add a background layer that is just white, so you can see what you are doing...put that on the bottom. Make another new, transparent layer and put that on top and work on that. Then when you think you are done hide all of the layers and save. You have to export the image when you save it as a TGA because it can't handle layers.

Hi Sonia,
can you give us a step by step on how you are using the Gimp Alpha Channels.
Just explain the menu selections and whatnot from the getgo.

I'd really appreciate it.
I learned to manipulate photos mostly by using Gimp and not Photoshop.

A.

I am still new to ps and am trying my best to learn as much as I can. I am using PSE 4. I can do almost anything but make something transparent. I follow all the step but you mentioned something I not notice before. What do you mean by saving one selection instead of multiple ones? I tried reading all posting on this thread but sometimes get lost. Thanks

Hi Kat!

It's very simple, really. Every time that you Save a Selection in PSE, you are making a new Alpha Channel. You can't see that's what you're doing, because you can't see the Alpha channels; but it is.

Targa (.tga) files can only have one Alpha channel. (That's why they are 32 bit files. 8 bits each for the Red, Blue, Green and Alpha channels.) If more than one is present, PSE doesn't know what to do, so it makes the Alpha totally white, giving you a completely opaque image.

To fix it, you need to eliminate the extra Alpha channels. (Select > Delete Selection.) I suggest that you name the channel you want to use Alpha, for obvious reasons. When you are ready to save as a 32 bit .tga, make a copy of the whole file (Save > Save As...), and delete all the extra channels.

You'll find that with exactly one, your transparency will show up in SL without trouble.

Hope this helps!

Thank god! *falls over*
As a note for PSE 2.O Users, please check to make sure that you do not have a current alpha layer, you have to delete the alpha layer if you have one before you can create one! You can only have one layer and then your good Wahoo!

Hi Rhyssa!

You are very welcome.

But, ummm.. it's alpha channel. There is no such thing as an alpha layer, and if Chosen sees you say that, he'll slap your wrist!

Channels and layers are two very different animals.

Checking to make sure that you only have one Alpha channel is good advice for everyone, no matter what Graphics program you are using.

There can be only one!

Ok, the more I read, the more confused I get . But I guess that normal for me. I think I need to find a PS for dummies so that I might can follow a few instructions. I am at work now, but when I get home, I will get my book back out and try and find how I can tell if I have one alpha channel or more than one open (or active or whatever you call it). Just to learn how to make simple transparency, nothing fancy, I am making just a single character tattoo. So far, using PSE 4, following all the steps, I end up with only a headache . Oh well, I will keep trying and maybe I find out what I doing wrong. I am sure that I must be missing one or two steps along the way. While I was not trying to do so, I did end up with a nice (not great) t-shirt while trying to learn all this. Thanks for all the input here, it is indeed very good reading, and though I might be slow, I am learning alot just by what all is talked about here.

Hi Kat!

You're not a dummy; you're just trying to learn a new language. It doesn't help that most of what's here is written for a program that's kinda like the one you're using, but not exactly like it. (I don't like the whole "for dummies" concept, because it's always felt self-depreciatory and therefore self-defeating to me. I wish they had named those books "for novices" or "for beginners" or "for non-techies" instead. )

Photoshop Elements doesn't have a Channels palette, so it's easy to get confused. It's like going to the salad bar with chopsticks while blindfolded (in the words of a friend of mine.)

However, even though you can't see the Channels directly, it's not hard to see how many you have. Just go to Select > Delete Selection. That will pull up a list of all the saved selections (which are really channels) you currently have, so you can choose which ones to delete.

If there is more than one thing on that list, you have more than one.

If you have more than one, you won't be able to successfully make a 32 bit .tga to use in SL.

To see what they are, you'll have to Load them. Or you could just delete all of them, if you want to be safe, and then make a Selection that's what you actually want to use, and Save that.

Just remember, Saved Selection = Channel and there can be only one.

Hope this helps!

Ok ... I've read *EVERYTHING* I could find on this issue; I must be missing something.

My goal:
I want to create "skin" that's totally transparent except for my texture. I want to look "hollow" with my texture "outlining" me.

What I've done:
I created my images in Photoshop CS2 (on a Mac) with the appropriate alpha channel. I then saved it all as a 32-bit Targa and uploaded it to SL.

What I get in RL:
When I preview my images in other tools, what's supposed to be transparent is, and what isn't - isn't.

What I get in SL:
When the image first uploads to SL, the preview pane shows it as a flat image - AND YOU CAN SEE THE GRAY CHECKERBOARD PATTERN WHERE THE IMAGE IS TRANSPARENT. As soon as I choose "male head," a golden brown face is shown with my texture wrapped around it. When I zoom in on the preview, the eye holes are wonderfully empty; you can see the inside of the back of my skull. On the first upload/preview, I ignored the fact that the head was represented as this golden brown thing; I just thought this to be a convenience offered by the SL client. I proceeded with the upload, paid my L$10 (again and again and ...), went to "edit appearance" and - BAM! - the most I can do is apply my image as a tattoo texture. That means the underlying skin (generated by SL) shows through and my illusion of being hollow is destroyed.

So I don't want to make a tattoo - an overlay; I want to make "new skin" that's totally transparent except for where I have my other-wordly image.

How stupid am I? What am I missing?!

Hi Nava!

What you're missing is the existence of the Base Skin under everything else.

Avatars cannot be made transparent by use of a texture, because the base skin layer is under all the other layers, and is opaque. So, where you have transparency in your Skin, the avatar will show that base skin layer.

This is used by some skin designers to make skins that allow the sliders (which work on the base skin) to change various attributes.

If you Preview not as a flat image, but as the body part you intend to put the texture on (the Preview As is actually a drop down menu, and you can choose any of them.) you'll see the Base Skin as a sort of nasty mustard color behind everything else. (I think they picked that color because it's very unlikely that anyone would make anything that particular shade. )

That will let you see where your skin will show the Base Skin, and where it will be opaque.

There will still be empty eye holes, but that isn't because the eyes will actually be empty. That's because they are a different mesh, and aren't shown in the preview.

There are ways to make part or all of your avatar transparent, but they involve using prims with scripts that make anything with a 32 bit .tga texture transparent; so I don't think you can have both the texture you want and a transparent AV. I think you'd have to build your "texture" out of solid prims.

(I've never used one, so someone please let us know if I'm wrong, and you can.)

But yeah. If I understand you correctly, your problem is that what you are trying to do isn't possible with the current software.

Sigh.

Nava, first read what Robin said so you understand what's going on, and then if you really wnt to build a cell shaded av, here's what I'd recommend:

1. Cover your body entirely with invisiprims. Use one for every single limb, every digit, every facial geometry feature, etc. (Search the forums for "invisiprim" if you don't know what they are.)
   
   
   
2. Cover each invisiprim with a slightly larger hollow sphere.
   
   
   
3. Apply a black texture to the inside of each sphere, and set the transparency value for the inside surface to 1. Apply a totally transparent texture to the outside.

What will happen is since you can see through the outsides of spheres, the black inside surfaces will appear to form outlines around whatever's inside the spheres (standard cell shading technique in SL). Since invisiprims hide avatars and 32-bit surface textures, you'll have those outlines appear to be around just empty space. Voila, invisible, cell shaded avatar. As long as you don't stand in front of any other 32-bit surfaces (like walls with windows), the effect should be fairly convincing as long as you've built everything right.

Keep in mind, it'll take a lot of sculpting work to make the results of this look as human as the regular avatar model does. You're essentially building a robot. Making it look organic will take a lot of spheres.

And by the way, you don't have to use just spheres. You can use any shapes you want. Just make sure each outline object is the same shape as the invisiprim inside it, and the outlining effect will always work.

I'm dropping a sample on your profile now.

i'm tryin to make a tattoo and i followed the directions for the paint shop pro but when i go to upload the image its not transparent but a light gray can neone tell me what im doing wrong and like talk me thru the steps...??

Well, talking you through the steps is likely out since that's what I already did by writing the tutorial. All the talking (writing) I did then was the most thorough way I know how to explain it.

In any case, if you're not seeing transparency it's because your TGA file is not 32-bit. You don't have an alpha channel present. Make sure to always save all your images as 32-bit TGA if they need transparency, or 24-bit TGA if they don't.

If the "light gray" you're seeing is not opaque, but translucent, it's because the areas in your alpha that are supposed to be black are not truly black. Any grayscale value other than absolute zero in the alpha will represent some level of opacity.

Those are the only possible explanations for what you're seeing. Without watching what you're doing, I can't pinpoint precisely where you're deviating from the tutorial. All I can say is follow the steps exactly without changing a thing, and it will work. If you contine to have trouble, it might be a good idea for you to explain exactly what you're doing, step by step, as specifically as you can, and then I can probably find where the problem is.

I can't thank you enough for this more than fantastic tutorial and FAQ you listed here. This is amazing. I think this week alone I have read the most information in several areas of this forum than ever before. I've been relentlessly trying to finally find the tut that would best suit me...or I should say explain the basic concept of alpha to me. I could not find the right one using paint shop pro that was able to explain how to finally lose those white necklines and sleves when making dresses, shirts or bikinis. Thank you so much ))))

Duh, now I see what I have been doing wrong with PSE4. I have printed this thread and have read it several times but just now noticed what you said, and I have not been doing that. I know you addressed this to PSE 2 users but I also remembered that with my PSE 4 the alpha layer is already there. I can hardly wait to get home from work to try it out. Thanks so much.
Kat

I'm glad people are benefiting from this thread, learning from both the OP material and from each other in all the follow up posts, but please, for the love of all that is decent in the universe, can we please refrain from using the phrase "alpha layer" from now on? There's absolutely no such thing as an "alpha layer". It's an alpha channel. Got it? C H A N N E L !

One more time, that's alpha CHANNEL, not layer.

This forum is the only place in the entire universe where people constantly insist on interchanging the words "layer" and "channel". It confuses so many people. Please stop doing it.

Layers and channels are entirely different things. Please refer to them as such.

Thank you. End of rant.

-Chosen

Thankyou so much for this information I have spent hours trying to get my work transparent so I could use it on SL 5 minutes reading your tutorial and I have it.

Thankyou this is excellent.

Jaylee Asp

Sorry about that Chosen, the thing is that I know better. Even after I posted that I was talking with a friend and used the word "Channel" when telling her what I had learned. Forgive me for having a blonde moment?

Chosen (or anyone else who can answer this)

I'm using photpshop cs2.

I followed your test example copying your test gradient image, and pasting it into the alpha layer, and it looks fine as it should.

I save the 24 bit targa file

If I reload that targa back into photoshop, shouldn't I see the alpha channel still in it? if I do, I get no alpha channel loaded, just the usual rgb, red green blue.

and if I load it into sl, I get no alpha transparency effect.

I've used photoshop for years, and never had to deal with the targa format before. is there some weird save issue with it in cs2?

I'll refrain from bitching about the use of the word "layer" instead of "channel" since you did say it right the second time, but you can scroll up a couple posts if you want to feel yelled at anyway.

Your problem Garee is that you saved the file at 24-bit, which means your image contains no alpha channel. There are 8 bits per pixel in each channel, and since 8 x 3 = 24, your 24-bitimage only has three channels in it. The first three channels in any RGB image, whether it be TGA or otherwise, are always Red, Green, and Blue. In TGA files with transparency, the transparency comes from the fourth channel, which we happen to call Alpha.

If you want to keep the alpha channel in the file, save at 32-bit. 8 x 4 = 32

Sorry about the phraseology issues. I tend to "read past" mistakes ppl type when posting.

In the 8 pages of thread, I TOTALLY missed the 24 bit/32 bit explanation, and your answer was right there all along. I was doing everything properly instead of the final save.

I even tried a psd to targa conversion program, but that did not retain the alpha at all either, but saving 32 bit does the trick.

Thanks for the speedy reply!

I think your problem is that since PSE has no channels palette, you can't be certain you've gotten rid of the alpha channel that comes with the template. I would suggest you copy all the layers from the template into a brand new document. That way you'll know for certain there's nothing in it you didn't put there yourself.

And by the way, don't confuse the sample alphas that are stored as layers with actual alpha channels. Deleting those layers or not will make no difference. Layers and channels are entirely different things. The reason the samples are on layers is just so that they'll be inert if you don't use them, harmless. Were they actually stored as channels, there would be way too many channels, and you'd have to delete them every time you open the template file to make a new image,. That would be a big waste of time. To use any one of those samples as an actual alpha, simply copy it to a channel (and make sure it's the only alpha channel present, of course).