How do you make a window texture?

This is what I want to make, except the bars to be white and everything else is transparent.

http://spiralforums.biz/uploads/post-2-1143523599.jpg

I've tried background erasing, but I suck at it :/

Don't erase anything. You can recolor the bars, and then use them to make an appropriate alpha channel, in about ten seconds. Assuming you're using Photoshop, here's how:


Part I: Whitening The Bars

Since you want the bars to be white instead of yellow, let's do that first. This will actually put you half way toward the alpha channel you need, so you're almost killing two birds with one stone. Do this:

1. Grab the rectangular marquee tool, and draw a selection box over one of the bars, all the way across the image. You can pick a horizontal one or a vertical one; it doesn't matter at this point. Just make sure the selection covers the bar, and nothing else.

2. Hold Shift to add to the selection, and then repeat the process to draw selections over each of the other bars.

3. Press ctrl-J to make a new layer from the selected area. Name this new layer "White Bars".

4. Click once on White Bars in the Layers palette to activate it, and then click Image -> Adjustments -> Desaturate. This will remove all coloring from the layer. Your bars should now look gray.

5. To turn the bars white, click Image -> Adjustments -> Brightness/Contrast, and then crank up both sliders until you've got the amount whiteness you want. Raising the Brightness slider will make the base color more white. Raising the Contrast slider will help to preserve the grain.

Your bars are now white.


Part II: Making the Alpha Channel

This will be really simple. You've already done most of the work.

1. In the Layers palette, ctrl-click (or cmd-click if you're on a Mac) the thumbnail for the White Bars layer to select everything on the layer.

2. In the Channels palette, click the Make New Channel From Selection button. It's the one that looks like a gray square with a white circle in it, second from the left, at the bottom of the palette. You'll now have a new channel in your image. By default, it will be named Alpha 1.

3. In the Channels palettel, click once on the word "Alpha 1". This will turn on visibility for the alpha channel, and turn off visibility for the color channels. You'll now see that the alpha channel is white in the shape of your bars pattern, and black everywhere else. This indicates that the image will be fully opaque in the shape of the bars, and fully transparent in between.

4. Since you probably want the window glass to be translucent, not invisible, you don't want all that black in the alpha channel. You want gray. So grab the paint bucket, and set your foreground color with gray. If you want the glass to be 50% transparent, use 50% gray (127,127,127). If you want it to be more opaque, us a lighter gray. If you want it to be more see-through, use a darker gray. Flood the black areas with your gray of choice.

5. Save as 32-bit TGA, and upload to SL.



These steps may have seemed like a lot, all written out like this, and they may have taken you several minutes to follow, since you were reading at the same time as working. But in actual practice, if the whole procedure were to take you any more than 10 seconds or so, you'd be going at a snail's pace. This kind of alpha masking is very quick.

The important thing to remember here is when editing existing imagery, never ever erase, period. The eraser should only be used when drawing or painting, to clean up your own brush strokes as you go. It is absolutely not for removing backgrounds or any other parts of an image. Instead, always use alpha channels or layer masks. In this way, you work non-destructively at all times, and you finish much faster.