Layer Primer

The layer system is used to show different frames of one or more projects at the same time. This is done by laying them on top of each other as a stack of layers. Depending on the graphic portions that are transparent on each layer you can see the pixels of the layers below.
Additionally you can set a layer transparency value to see layers shining through partly.

The layering can be used to cover the following different use cases:

Onion Skinning
When you are drawing animations then you want to have smooth movements. One approach to have smooth movements is to first draw just some key frames defining the overall movement. If this is done then the frames between these key frames are drawn, the inbetweens. When doing this it is helpful to see some of the key frames at the same time when drawing the inbetweens.


Multi Layer Animation
Sometimes it is useful to split an animation into separate object layers for later reuse. For example you have created a walking game character and this character may optionally carry a back pack. Then it would be necessary to have the sole character animation and a separate layer that contains the back pack. During the game the back pack part can then be switched on or off. For creating such use cases you can define layers showing different animation feeds where each animation is a separate project.
This mode can also be usefull to check an animation agains a fixed or animated background.



Multi Layer Image
If you want to create an image that should display different objects or graphic portions that can be modified independently then you may use frame based layering. In this mode every "animation" frame of the project is supposed to be a layer.



Increase Color Depth
Generally you can have a single color palette for all frames or each frame can use an own color palette. When using different palettes per frame while using these frames as layers you can have 256, 512, 768... colors per image. You just need to set up the frame palettes so that they build your overall palette. If you want to use colors defined in the palette of frame X then you switch to this layer and place the color pixels there.
This is just the same as having a multi layer image or animation but with different color palettes.




General Usage

To activate the layer system you may use the corresponding options in the menu layers or click ob the layer icon in the tool box.
It is suggested that you save layer enabled images or animations as a project file because the layer settings can not be stored in standard image or animation files.
When the layer system is activated then the settings window appears. You may close it temporary if you don't need to change the settings. Right click on the light bulb icon will open it again.
In this settings window you can define the layers you need. The layer list represents the stack. The ones at the top cover the layers below.

For every layer you can use the check box to make it visible or invisible.

Sample: Onion Skinning

If you want to use onion skinning then you must tell the layer system which layer has to display which key frame relative to the frame you want to edit. To concentrate on the shape of your animation you can set up the layers to show a fixed shape color for all non transarent areas of a frame.
  

For this example we define three layers that display the current frame of the animation, the previous and the next one. We also set up a special shape color so that the details or the actual colors within the animation shapes do not disturb. Additionally we select a white overall background.

  

For every layer you can see a short description that shows the selected options. Onion skinning needs a setting for every frame that defines which frame is to be displayed based on the current one. This is done using frame delta positioning. That means you define that e.g. layer 1 has to display the current frame - 1, the previous frame:



The other frames are defined similar. Be sure that you also define a layer for the current frame. Otherwise you won't see any changes if you edit the image.
To check the animation flow you can switch frames back and forth easily with the defined shortcuts ("1" / "2" is default).

Sample: Multi Layer Animation

As an example consider you have created a walking character. This character should be able to wear or to carry different clothes or items while the walk movement remains equal. In this case you can create the sole character animation as a single project. The different clothes or items would be added using separate projects. Using the layering you can bring everything together visually while still working on separate animations.

  

In this example we have two layers, the walking kid and its blanket where the animations are done in two different project files:

    

The layer settings do just define different projects for the layer display contents. The same layer delta position mode is used as with onion skinning, but in this case the delta is 0 because we want to display frame 1 of layer 1 at the same time as frame 1 of layer 2.
If you select one of the layers then the corresponding project is activated so that you can edit it.

To create a merged animation where character and blanket are visible use the function melt frames or Export as Images... in the menu layers.

Sample: Multi Layer Image

When assembling images that contain different independent objects overlapping each other then moving and placing them around can be difficult when not having independent object layers.

  

For this image three layers have been defined, one for the background, one for the fishes and one for the score display. Each layer is defined to display a frame of the project. In this example the layer with the fishes just displays frame 1 of the project:



The other layers display frame 2 (score) and frame 3 (background). If you select a layer from the layer list then the frame that is displayed by this layer is selected and you can edit the bitmap data, e.g. cut and move objects.

If you start to create a multi layered image then it is suggested to define a couple of frames first that you will need as layers. Then enable the layer system and use the button to automatically create a layer for every frame.

Sample: Increase Color Depth

Working with gaphics based on color palettes differs much from using true color techniques. One important thing is to have a good sorted color palette with ranges of color shades that make up you image or animation color spaces.
The usual palette size of indexed color graphics does not exceed 256 colors, but sometimes more colors are needed. In this case you can use the layering system to increase the color depth. This is possible because every frame may have its own 256 color palette. Displaying such frames as layers will show all the frame colors at once.

  

The layers are defined just the same way as with the muli layer image sample. The only difference is that the project's frames do not share a single color palette, but every frame has it's own palette. You can have individual frame palettes by deactivating the "Global Palette" which is the "G"-sign at the top of the main form.

Alternatively you can set up your layers to use different projects. This is useful when doing hicolor animations. Then each layer has its own color palette.

To export the hicolor image data just use the function Export as Image(s)... from the menu layers.

Related topics

Layer settings
Layer Settings
Pro Motion Online Help Contents
Menu Mode
Tile Mapping Primer
Tips
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