Photoshop CS3 Alpha texturing issues

Recently I re-formated, and decided to upgrade to CS3..good program so far, but I'm having issues generating Alpha textures like I used to on CS2, I remember I had a plugin for CS2 that allowed for very easy, and very quick alpha maps. transparent background, and the magic wand was all I needed to make alpha textured cut-outs of things, I'm sadly finding that CS3 has the same problem. I was wondering if anybody knows if where such a plugin for CS3 would exist, if it exists at all.

Considering the garbage I upload, I would honestly rather a quick fix like this, as opposed to spending 2-3 mins on a texture that only took 20 seconds to make.. just to have it SL compatable.

Kinjry, please don't take this the wrong way, but if it takes you 2-3 full minutes to make an alpha channel, then you must be working blindfolded with both hands tied behind your back. It's a ten-second process if you're really slow, a 2-second process if you're average, and about a half-second process if you're quick.

Here's the simplest thing procedure, given your description of how you've been working:

1. Work against a transparent background, just as you've been doing.

2. On the Layers Palette, ctrl-click the thumbnail for the layer that has your stuff on it. This will select everything on the layer. If you've been working on multiple layers, simply hold down shift and ctrl-click additional thumbnails to add to the selection.

3. Go to the Channels Palette and click the button at the bottom for Save Selection As Channel. It's the one that looks like a gray square with a white circle in the middle.

That's it. You're all done. You've now got an alpha channel that exactly matches the transparency values of your image. I'd suggest taking the extra step at this point to add a de-haloing layer, but since you seem to think your images are "garbage" anyway, I'm guessing you won't want to invest the extra second or two that that would require. Save as 32-bit TGA and upload to SL.

Now, if that 3-click process I just described was too complicated for you, you could always download and install the action made by Robin Sojourner, which turns it into a one-click process. You can find it at http://www.robinwood.com/Catalog/Technical/SL-Tuts/SLDownloads/SLTranspPSDAction.zip





As for that plug-in that you asked about, do yourself a favor and forget all about it. Believe me; it's not a time saver at all. In fact, for many things, it actually requires you to spend a lot more time to get the same results, not less. There is nothing faster or more reliable than using real alpha channels, which is why they've been in existence completely unchanged for more than two decades. Alpha mapping is one of the rare examples in computing of something that was gotten right the first time.

That plug-in will FUBAR your Photoshop. If you'd like to know all the problems with it, read the transparency guide at the top of the forum. There's an entire section dedicated to it. Trust me; it's a lot more trouble than it's worth.

All that having been said, if you're really deadset against using alpha channels, then use PNG instead of TGA. PNG allows for the use of WYSIWYG simple transparency. It's nowhere near as powerful as alpha transparency, and it's not a time saver (in the same way that plug-in is not a time saver), but it will allow you to work exactly as you were working before.

Hi Chosen,

Can I ask a couple of simple questions? I have managed to make some transparent alpha channels but it is usually by accident and only after many many attempts. Thus I am missing some key, basic, fundamental concept(s).

I have a photograph (taken in SL actually) of a gray tube against a green background. Apparently I need to make the green background transparent prior to creating the alpha channel based on that. At least your point #1 above would suggest that I need to start with a transparent background. How does one do that in Photoshop? I can select the tube (or the background) no problem, but I don't know how to make the green bits transparent.

Perhaps a different way to ask the questions is at what point can I use the actions made by Robin? I have installed them along with the Flaming Pear Filters but all I ever get out of those actions is a totally white alpha channel.

Thanks in advance for your help,

Doug Danforth

Hi DrDoug. I'd suggest you begin by reading the transparency guide at the top of the forum. You'll find in it four different tutorials for Photoshop, one for Paintshop Pro, and one for Photoshop Elements, plus all the conceptual information you'll need to understand the why's behind the procedures. If there's anything in the guide you don't understand, ask away.


Actaully, you don't have to do that. My Point 1 in this post was based on the original poster's existing work habits. You don't have to work that way at all. You can certainly create an alpha channel with that green background in place. Since the transparency data is contained in the alpha channel, not the color channels, you can easily use the alpha to hide the background without making any other changes to the image.



There are a number of ways to do this (but, I repeat, you don't have to do it at all). Don't take this the wrong way, but since you don't know any of the numerous ways to remove or hide the parts of an image that you don't want to see, it sounds like you're brand new to Photoshop. If that's the case, do yourself a favor and learn the basics of the program before you try to learn to texture for 3D. Learning Photoshop for the first time and learning to texture are two different things. The latter obviously depends upon the former. Trust me; if you try to put the cart before the horse you will regret it. This is the advice I give to everyone. Take things one step at a time; don't try to skip ahead.

Take a week or two doing 2D projects to learn how Photoshop works. Once you've got a comfortable feel for it, a good command of how to use its basic tool set, then come back to learning to texture. If you don't take this little step back now, you're almost guaranteed to run into huge stumbling blocks later.

Unfortunately Photoshop 101 from A-Z is beyond the scope of this forum. If someone volunteers to step up and explain it to you from scratch, great. But I really don't have the time, sorry.

All that having been said, the simplest way to remove a solid colored background is just to click on it with the magic wand to select everything that's that color, and then press Delete. I have to stress that this isn't the best way to do it, just the easiest. For best results, I recommend never touching the magic wand. It's a clumsy, blunt instrument. For an image like the one you're describing, I'd use a channel mask.

Go to the channels palette, and view each channel one at at time. Pick the one that appears to have the most contrast and duplicate it by dragging its thumbnail onto the Create New Channel button at the bottom of the palette. Based on your description of your image, I'm guessing the channel you'll want to dupe will be the red channel. The green background will probably look quite black on the red channel, and the gray tube should look fairly whitish. If that's not the case though, then as I said, pick the one that you think looks the most contrasty and duplicate that.

Rename the new channel to Alpha 1 (renaming is not strictly necessary, but do it just so we have something to call it). Make sure only Alpha 1 is visible and that it is activated (highlighted in bold) in the channels palette.

Now, go Image -> Adjustments -> Levels. In the dialiog that pops up, drag the sliders around until the background looks black and tube looks as white as you can get it. Use dodge & burn tools from there to darken any parts of the background that are not as black as they could be and to lighten the pipe area as much as you can. Since it's such a simple image, you might even just want to paint over it with black and white.

When the tube area is completely white and the background is completely black, save the image as 32-bit TGA and upload it to SL. You're done.

Keep in mind, what I just described is just one of about a thousand possible methods for removing a background. There are simpler ones and there are more complicated ones. As you get experience with Photoshop, you'll discover which methods you prefer to use for what purpose.



The reason the alpha channel is coming out completely white is because that action is designed for working against a transparent background in the image. For a pre-existing, completely solid image like yours, you'll need to work manually. If you really, really, really want to use the action, you'll need to extract the subject from the background first. That's exactly the same amount of work as making an alpha from scratch anyway, so you might as well just make the alpha.

I have done that. About 5 times .


I think I did that yesterday .


That's the way I have done it in the past. I just was wondering if making the green background transparent was an easier approach.



I have been using Photoshop for about a month. I can use many of the tools, but I am not very familiar with actions, channels, and many/most of the filters. As I mentioned, I can (usually) easily select the bits I need or don't need.



First let me say that I genuinely appreciate all of the tremendous help that you have provided on this thread/topic. And I certainly don't expect a PS tutorial. But from banging on this for a while, and reading and re-reading the transparency thread, it seems that there are a number of folks in a position similar to mine. I have a relatively simple image, parts of which I need to make transparent. The tutorial in the transparency thread (which again is excellent and most appreciated ), seems to be missing one or two key basic photoshop steps that are consistently tripping folks up, as judged by the number of dazed and confused replies. These are photoshop 101 things that, while not necessarily germane to the alpha business, are nonetheless absolutely essential to getting the whole process to work.



I have tried this. Sometimes I get a transparent background (gray checkerboard). Other times, not. I suspect that my problem is that my background is not a single color. The background I used in SL was a giant sphere and I think the lighting/time of day was creating subtle shadows. I didn't actually use the magic wand, I just selected by color.




Thanks for that excellent and thorough explanation. I will try that.



This makes sense. I don't necessarily want or need to use that action, it just seemed like it combined the alpha channel creation with the white halo removal in one easy step. And if I could easily remove the background (select green, delete, voila'), then the action would seem to be a good way to approach this. Otherwise, I need to create the alpha (not allthatdifficult) then perform the white halo removal (somewhatmoredifficult).

Thanks again for being one of the truly altruistic folks here.

Doug

If your image is on the background layer and you delete or erase a section, the erased section will become the colour you have selected as your background colour under your colour picker. Hold down alt/option and double click on the background layer in your layers palette to release it from the background layer. Now if you erase a section, it should be transparent.

Thank you Betty.

I sorta new that but kept forgetting to release the background layer. Kept getting a white background instead of a transparent one.

Robin's actions now work - sorta. As long as I don't use the Flaming Pear filters they create nice alphas.

The minute I use the action with the filter - the image gets pretty ugly.

Never Give Up
Never Surrender

Doug

I just read a lit about some people having probs with surten aspects of paint or photoshop,there are numerous tutorials on the net covering these application in all aspects.
Meselfs i'm not a light meselfs in paintshop or photoshop,but i have to say that what i read is simple and good and fast way to have a alphacannel imageLet me give you one link to a hole bunch of tutorials about paintshop)
But if you do a search on Google or other search enigines??? you gone find ton's of tut's about these progs)


http://www.psplinks.com/index.html

there ,i'm sure you gone find a lot of good info and things to try out )

Good luck

You're welcome, Doug. Have you tried uploading the one with the filter used? I've never used Robin's action, but that's what your file is supposed to look like after using Solidify. Basically, what it's doing is taking the edge colour of your tube thingy and bleeding it out so that you will have like colour next to like therefore getting rid of that halo.

Um, well, gulp, no I actually didn't.

So I did.

Voila" WorkedLikeACharm .

You're a genius!

Interestingly, there was no visible halo around the tubule either way, once I got them into SL.

Thanks a million,

Doug

p.s. BTW, the tubule I'm working on is part of the testis. I am building a giant model of the human testis so my students can visualize how the anatomy and the physiology of the structures interact to produce sperm.

Wonderful! What an interesting project. I'm guessing you wouldn't see the halo because of the colour of your image. It's pretty much the colour the halo would be. However, when you get to a darker coloured part of the anatomy you most likely would.

@ Chosen Few
for one I was trying to work off the CS2 tutorials, and you take me too literal when I say 2-3 mins, Just trying to express it was time consuming compared to what I had earlier, so theres no need to get uppity, that aside I can say thank you now for the info, the process is pretty easy and simple, problem was I was using CS2 methods, I didn't think they would be that different. Now that I know the difference, its easy. thanks

Kingry, apologies if my wording was taken as anything less than friendly. It wasn't meant to be at all rude, but after re-reading it myself, I can see how it might have sounded that way. I guess in the same way that I had no way of knowing that your "2-3 minutes" thing was not meant literally, you had no way of knowing how my tone was intended either. Sorry.

Anyway, glad you got it all worked out.