GIMP Tutorials

INTRODUCTION

This tutorial will show you how to use and manipulate layers in Gimp. For clarity's sake, and because my explanation skills are not so great, when I refer to the dialogue window I mean the Layers window. Image window means the entire drawing window where your soon to be masterpiece awaits your creative skills.

The layer dialogue in Gimp, has most of the features available in other comparable programs, such as Photoshop. Using layers is essential for making skins, and learning to use them to your advantage will help you produce good results.

GETTING STARTED


The first step in getting started is to make sure you have the Layers window in your taskbar. It may not be there when you first install Gimp, and granted it can get cluttered down there with alot of open windows, but having it there and ready to be used makes things alot easier.

Start Gimp and then create a new image of any size. If you don't see an item in your taskbar named Layers, Channels, Paths, look to the top of your image window screen and click Dialogues. Now click Create New Dock and then Layers, Channels & Paths, as in the image below.




Now you should have a Layer dialogue window similar to the one underneath.

Having this window handy at all times is almost a requirement for making skins. As you progress on your work, you will find that you will switch layers alot, shut layers off, lower the opacity of them and all sorts of things.

THE LAYER DIALOGUE WINDOW

This window has numerous options to make your layer fit your needs. Sometimes you may need a layer, such as a weathering detail, to be not so "visible", so you lower the opacity of it to make background items visible through it. This is only one of many ways that a layer can be adjusted to fit a particular purpose. Let's get to some basics.

Creating a new layer is done simply by clicking the New layer.. button at the bottom left of the window. When you click it a new window pops up. This window allows us to enter a certain size of the new layer, name the layer, and also select the layer fill type. By default, the layer size will be the size of the entire image. For example, a standard void file is 1024x1024, so your new layer will automatically be that size. Not to worry though, if you want to resize it later you can.


The size and name options are self explanitory, but what about the fill types? They are quite simple too. Choosing the foreground colour option will fill the layer with the same colour you have chosen as your foreground colour in the main Gimp window. Background colour does the same, but with your current background colour. White means that the layer will be filled with white. Transparency will leave the layer transparent with no colour whatsoever. For skinning purposes, Transparency is the choice of layer.

For now, create two new layers, with transparency as the Fill Type. Now you see that some buttons that were greyed out, are now available for use. To the right of the New Layer button are two arrows. These are the Raise layer and Lower layer buttons. Clicking these buttons will move the layer that you have currently selected up or down. You can also click and hold on the layer and drag it up or down.


You may notice that you can't lower a layer underneath the Background layer. That is because the Background layer can't be transparent by default. We can, however, make it transparent so that we can put a layer underneath of it or even erase parts of it. For now, we'll stick with the basics, and get to that later.

Next to the Raise and Lower layer buttons is the Duplicate layer button (circled in green above). This will create an exact duplicate of the layer you have selected. Everything that is on that layer, will be made into a new layer.

The next button has an anchor on it. This is the Anchor Layer button. If you have copied a layer, and want to paste it down, or anchor it, pressing this button will do so.

The last button is the Delete Layer button. This can be a source of anguish, despair and gnashing of teeth if pressed by accident. Don't worry though! Almost everything done can be undone. If you find you have deleted a layer and really need it back, simply go to Edit in your image window, and click Undo.....whatever you just did. Pressing also undoes an operation.

At the top of the Layer dialogue are some other functions.
The very top contains a bar which has the name of the image you are working on. (circled in red below)
This tells you what image the layers shown are from. If you are working on more than one image at once, you can click on this bar and switch between the layers for each image.
There is a button to the right of this bar named Auto. When this is activated, this causes the layer dialogue to "follow" the image you are working on. For example, if you are working on a Zero skin, and need to switch to a Markings template, the layer dialogue will change to the Markings image automatically, without you having to do so with the bar. This is very useful.


Underneath of the Layer bar and Auto button, you will see some tabs. Depending on how you have set Gimp up, you may only have one. In the image above there are four. Circled in green you can see a small arrow button, and an X button. Pressing the arrow button brings up a layer related menu. One of the things you can do in this menu is add more tabs to your Layer window. This keeps the clutter down in the task bar, and is useful if you have alot of windows open at the same time. Clicking the X closes and removes the current tab. Don't click this unless you don't want the tab anymore.


Finally, in the middle area of the layer window, we have the layer mode dropdown, the opacity slider, and the layers themselves.
Clicking the layer mode dropdown brings up a whole slew of different mode types. Each mode type has it's use for a particular aspect of skinning. The times when I most often change a mode is for weathering a skin. I'll try to put together a tutorial for that in the future. For now, just experiment with the layer modes to find out for yourself the effects they have.

The opacity slider simply sets the opacity of a layer from 0 (invisible) to 100 (fully visible). You can change the opacity by clicking and sliding the button, rolling your centre mouse wheel while over the slider, or by typing a value into the number box.

The layers are right in the middle of the window. As I said before, when a layer is highlighted in blue, it means that it is the current layer. If you draw some lines in the image, they will be applied to that specific layer.
Next to each layer, is a button with an eyeball on it. (below in red) This is the visibility button. When the eyeball is not there, the layer is invisible, or turned off. Click it again and it becomes visible.
To the right of the visibility button is a button that, when activated, shows a picture of a chain (circled in green). This allows you to group layers together for an operation, such as moving them. Every layer with a chain will be affected by the move.


Next to each image name, is a small thumbnail which shows what that particular layer looks like. A transparent layer will show up as a "checkerboard" with whatever you have drawn on it.

MAKING BACKGROUND LAYERS TRANSPARENT (ADD ALPHA CHANNEL)

As I said before, it is possible to change a background layer to a transparent layer. Sometimes this is a necessary operation. To do so, make sure the layer is selected. Now at the top of your image screen click Layer, Transparency, and then Add Alpha Channel. (You can also right click anywhere on your image and have all of the menus at the top of your screen, available right where you are working.)

Now your background layer has the ability to be transparent. You will be able to erase it, make it invisible whatever you want. It should be noted that when you flatten your image and convert it to the .bmp format, it will not be transparent. (No invisible planes unfortunately!)


That's about all for the basics of using layers. As always, playing around with various settings will help you get the hang of using them. Remember, the Gimp manual is available for download, and has context sensitive help at the press of a button. It has an excellent Glossary which explains the Layer mode types.