Clouds and Landscapes

The Smart Fill Handle appears when you click in one of the table cells in Figure 10. Select the first cell in each column and drag the Smart Fill Handle down a few rows.

In practice, it would make little sense to create an animation with just six frames. We chose this restriction to keep things simple and to illustrate the controls in Figure 10. What you need now are at least horizontal shifts of the individual slides. Click in the X-Sheet window on the cell in the first frame of the Col2 column; as you will recall, its name is clouds.

Then select the Animate Tool (A) in the toolbar at the top left. Make sure that Col2 and Position are selected in the Tool Option Bar above the viewer window. Now move the cloud layer inside the viewer window a little to the left with the mouse pointer. In the X-Sheet window in the first row, a small white key will then indicate on the right that you successfully defined a keyframe.

Now select the cell in row six in the same column and move the cloud layer inside the viewer window with the mouse pointer – this time to the right. A small white key now appears in row six. Do the same with the street layer in the Col3 column. Now click on the play icon in the playback controls in the flipbook bar below the viewer window to enjoy your first simple animation.

People and Actors

To complete the animation, you still need one or more levels with people, animals, or machines – actors, to use the industry term – in the foreground. OpenToonz offers several ways to add actors.

If you want to use a character from a real movie as source material, export the desired scene as a GIF file. You can then open the file as layers in Gimp, and then crop the actor frame by frame. Save the result as a transparent PNG file with consecutive numbering.

To import into OpenToonz, select Level | Load Level… and open the directory in which the individual images are located. OpenToonz then only offers you one file for all of the PNG files you just saved and numbered consecutively; in addition, the dialog tells you the number of individual graphics and the total size of all files.

After you click Load, the software loads the individual files and inserts them as a new column into the X-Sheet, like the one shown in Figure 5. However, in Figure 10, notice that the view only displays the file name for the first image in each frame – with a tilde followed by a 1.

In the case of the sky, cloud, and road layers, displaying the first image in each frame is fine because the animation is created by moving the layers. In Figure 5, the numbers change in some lines and are again followed by vertical strokes. Vertical strokes mean: Repeat the content of the previous frame in this frame. The numbers let you specifically display the numbered frames of the image sequence.

Skilled animators sometimes draw directly in the viewer. To draw in the viewer, select the empty sheet in the Level Strip and open the last level there (Col3 in our example). Then use Level | New Level… to create a new level and draw your actor directly using the toolbox. If you need more frames in the Level Strip, create them using Level | Add Frames… or directly in the Level Strip via the context menu using Insert.

Onion Skin Mode is an interesting aid that fades in green and red overlays in the viewer while drawing. This makes it easier to trace congruent elements between two frames and to make image changes more harmonious because they stand out quickly [5].

Defining Joints

Perhaps you have created a single image of your actor and want to change a part of it without having to redraw the figure completely. In such a case, the Plastic Tool will help you; you can press X to enable it. Then select the Create Mesh option in the Tool Option Bar above the viewer window.

A dialog with the same name appears. You can use this dialog to set the granularity of the mesh grid. Confirm by pressing Apply. A new column appears in the X-Sheet window with the same name and a _mesh suffix. This column represents a mesh layer with a wireframe model connected to the corresponding texture layer.

This connection is key to how the plastic tool works. Each column or layer connected to a mesh layer is deformed by the mesh and displayed within the mesh boundaries during rendering.

To animate a mesh plane, define a specific skeleton structure from a set of interconnected vertices. For each of the vertices, you can set various parameters, such as position, angular boundaries, and stiffness. To create the skeleton structure, select the mesh layer and enable Build Skeleton mode in the Tool Option bar.

To animate a mesh plane, first click on a point within the mesh layer that will not change under any circumstances during the subsequent animation – for example, the hip area if you want to animate the representation of a human being. Starting from this fixed point, define the directly connected joints by clicking on them. In this way, you can create a kind of tree structure. When you animate the subordinate nodes later, the underlying nodes will move along with them.

If you want to define the lower body joints, first define the position of the knee and the ankle of the left leg. Then click the hip again first, followed by the knee and ankle of the right leg. To define the joints of the upper body, click the hip again and then create the nodes for the shoulder, elbow, and wrist of the left arm. Once you're done with the left side, repeat the procedure for the right.

Once you have defined all the joints, change the mode in the Tool Option bar to Animate. After that, you can move the figure by clicking and dragging on the nodes indicated by squares – except for the hip joint, which is shown as a filled square.

If you drag the Smart Fill Handle of the mesh layer down in the X-Sheet, you can define the actor's poses for each frame because OpenToonz stores a keyframe with the parameters of its vertices inside the mesh layer. All you need is a drawing of your actor. However, you will also want to pull down the Smart Fill Handle of the connected layer beforehand.