Alpha Channel Discovery - Supplement A

A Second Life Tutorial by Robin (Sojourner) Wood. All rights reserved.
(Copying these pages and selling them as-in in Second Life, in any format whatsoever, is specifically prohibited.)

This is a supplemental page for a 3 page tutorial. To start from the beginning, click here. To return to the page this page comes from, click here.


There are lots of other things you can try, to get a feeling for how the Channels work.

For instance:

Try selecting some of your squiggles, and moving them around with the Move tools, so they intersect the other squiggles differently, and see what colors you get that way.

Try opening the Levels dialog (yes, you can use it on Channels,) and play with the sliders in that, and find out what that does to the colors in the image.

Try going in reverse, putting colors in the window on the left (remember to select RGB first, so you're working in full color) and see if you get the gray levels you expect to find when you look at the Channels.

Try flooding the image with White, and drawing on the Alpha Channel in Black, to remove that color from the image.

Try selecting two Channels at once. Any marks you make now will change the values of both simultaneously. See how that affects the image. (You can select one, two, or three of the Color channels, or as many Alpha channels as you happen to have; but you'll find you can't select Color channels and Alpha channels at the same time.)

You might want to add more Layers, and try drawing on those, and if you'd like to, feel free. But you need to know that painting on the Channel will only change the value of the pixels in the Selected Layer. So make sure you have the right one Selected. (And don't forget that you can't make new pixels, only change the values of the ones that are there. If you try drawing where you see checkerboard, nothing will happen.)

If your image gets too cluttered, you can Select All, and fill with Black again, to return to a clean slate. Or you can paint with Black on one of the layers, to remove just part of the colors.

Remember, you can't do this "wrong" or make a mistake. You're just playing here, discovering what Channels are, and what they do. The longer you play, and the more you try various things, the more you'll learn, and the deeper the learning will go. So have a ball with it!

Do whatever you can think of to do! Experiment freely, and see what you get. Keep notes if you want to, or don't if you don't. If you get it already, you can stop playing. If you want to see more, keep going. It's entirely up to you.

When you're ready, click here to return to the tutorial.


If you would like to see the other tutorials in this series, click here.

Everything on this site is copyright © Robin Wood; all rights reserved. Feel free to link to these pages, print them out for yourself, and use them yourself to create content for Second Life without restrictions. However, you may not distribute them in any way, (post them on your site, put them on a CD, use printed copies as handouts in a class, make books out of them to sell in SL, etc.) without permission. To get permission, write to Robin, and explain what you intend to use it for.