Game Development Reference
and the same rotation interpolated using quaternions. The Euler angle
rotation appears very messy by comparison with the quaternion rotation.
Pressing 'q' switches to quaternion calculations and pressing 'e' switches
to Euler angle interpolation. Pressing the 'm' key steps between the
possible alternatives for Euler angles, rotating through HPB , HBP , PHB ,
PBH , BHP and BPH . Quaternions, in actual fact, represent a path across
a four-dimensional sphere, but if like me you find such concepts difficult to
visualize, then you will just have to accept the results of the maths rather
than the justification for its use. It is very difficult to specify a rotation
directly using quaternions, so many programs use either Euler angles or
angle axis for the interactive display in a development environment and
quaternions for interpolation.
Using Toon3D Creator for keyframe animation
Now that we have the ability to create keyframes and are also able to
interpolate these key positions, we need some data. Run Toon3D Creator,
where you can experiment with animation paths. Selecting an object in
the tree control makes it the active selection. The buttons in the toolbar
allow you to switch between translation, rotation, scaling or sizing modes.
Moving the mouse while pressing the left mouse key will translate, rotate
or scale in the x - and z -axes. Moving the mouse and pressing the right
button allows you to translate, rotate or scale in the y -axis. Axes can be
excluded using the toolbar buttons. See Figure 8.4, where the toolbar
Figure 8.4 Toon3D Creator toolbar buttons.