CelAction 2D Tutorial 3: BUILD MODE – Group Shapes & Shape Links
Continuing on with the Build mode tutorials, we will look at shape groups. When you have a collection of mouths that you want to switch between for lip sync, or different outfits for a character, they can be grouped together. So a mouth Element can be one of several Shapes, such as open, smiling, frowning etc.
1: As mentioned before, only one default shape has to be added to the hierarchy for each element. To add the rest, select the element and press Alt + S to open the Element Shapes window.
2: From the ‘Add New Shapes’ dropdown box, choose ‘Pool’ to load up any unused shapes from your Hierarchy. Check the ‘Display Unused Shapes’ and ‘Keep Shape Position’ boxes. and add shapes from the pool to the group.
3: To make a new group, click the ‘Set Group’ button, then ‘Select’,then ‘New’ in the pop up window. Enter a name and click OK.
4: Now select your shapes and press Set Group again, this time picking the relevant group from the list.
All shapes in a group will be visible in the Shape tab at the bottom of the animator panel. To switch between them, just click your required keyframe, then click the required shape and it will change automatically.
Whilst some shapes will be changed manually when necessary – eye blinks, mouths etc. there are many things that can be automated – like a bird rhythmically flapping its wings.
1: In animate mode, select the element and the keyframes you need. Right click and choose ‘Animate Shapes’ to open a new window containing the shapes grouped with that element.
2: Select the ones you want and click the arrow button to add them to the sequence. You can adjust the order of the shapes with the arrow buttons, and select how long to hold each shape for. Press OK.
Now when you preview your animation your bird will flap it’s wings automatically.
It is possible to link elements so that when the shape of one changes, so too does the other – for example, when a bird flaps a wing and changes shape, the other wing will also change at the same pace. In order for this to work successfully, each element must have the same number of shapes to cycle through. To link shapes:
1: In the taskbar, click Actor > Shape Links > Manage.
2: In the Window that appears, check the ‘Link Back’ Button. This means that you could change either one of the birds wings and the other would follow suit.
3: Choose the First Wing on the left panel, and the second wing in the right panel. Press the Arrow button between them.
4: The shapes are now linked. Changing one element will change the other.
Hand drawn animation often features jittery lines, which can be very appealing if used correctly. To simulate this in CelAction, make 3 shapes for every element, then shape link them all to one element, such as the torso. Then simply animate the torso cycle and the rest will follow suit.
You need at lest three shapes per element – using two will just produce an unpleasant strobe effect.