Creating a Walk Cycle with Bones
Flash CS4 Tutorial
How to Animate a Walking Character in Flash
Bones are used to drive character animation or fluid motion such as a flag waving in the wind. They can also be used to simulate wind blown grass or the mechanical articulation of an robotic arm.
Bones are added to objects in multiple ways. It is possible to draw one or more Merge Shape objects, select the entire object, then add the bone structure. For more information on Merge Shapes and adding bones to Merge Shape objects, see topics, Merge Shape and Animating a Flag with Bones.
A second method of adding bones requires that you create your object as a series of Movie Symbols. Once you arrange your Movie Symbols, the bone structure is added with the Bone tool by click-dragging between the symbols. For more information on Movie Symbols, see topic, Movie Symbol Basics.
In this topic we will demonstrate how to make our character come alive and walk across the stage. This is the third installment of a three part tutorial. You need to complete the first two topics in the series, Adding Bones to Symbol Objects and Inverse Kinematics - Setting Constraints before you begin this topic.
Open your document from the tutorial, Inverse Kinematics - Setting Constraints.
Using the Selection tool (v key), marquee drag around your character and press F8 to convert it to a Movie Symbol. By placing the character in a symbol, we can animate the walking motion, then return to the main stage and add a Motion Tween to move the character across the stage. Name your symbol Walker.
Double-click the character on the main stage to open the symbol timeline.
At frame one of your symbol timeline, move the legs so the left leg is forward and the right leg back. This will be the starting position. You can also set the arms with the right forward and the left back.
Click frame 40 of the timeline and press F6 to add an identical keyframe at the end of the walk cycle. This will allow the cycle to repeat with seamless motion.
Click frame 10 and move the left leg to the center (straight leg) and the right leg to the center with a slight knee bend. The right leg should be slightly off the floor. Move the arms to a hanging, rest position.
Click frame 20 and move the left leg to the back and the right leg forward. Move the hands so the right arm is back and the left arm forward. This frame should be the opposite of frame 1.
Click frame 30 and move both legs to the center. This time the body weight should be on the right leg with the left leg slightly bent. Move the arms to the rest position.
Click the Scene 1 icon to return to the main stage.
Right-click frame one of the Armature layer and choose Create Motion Tween from the pull-down menu.
Click the last frame of the tween and move your character across the stage. A new keyframe is automatically added.
Publish your movie by choosing Control > Test Movie (Cmd/Return (PC-Ctrl/Enter). You may need to re-adjust your object at either keyframe to create believable motion.
Speeding Up the Walk
A quick way to adjust the walk speed is to double click the symbol. Once you are in the symbol editing mode, click and drag the final keyframe to the left. All the keyframes scale on the timeline and your character picks up the pace. The same is true for slowing things down. Simply drag the final keyframe to the right.