Graphics Programs Reference
In-Depth Information
5. Go to frame 31. Rotate the target node back to 0 in the Z-axis, move it down to 0 in
the
Y
-axis, and move it back a bit more in the
X
-axis.
6. Go to frame 35 and repeat step 4, but only move it half as much in Rotate Z, Trans-
late X, and Translate Y.
7. Go to frame 40 and repeat step 5, but move Target back only slightly in the
X
-axis.
If you don't freeze the transforms on the target's parent node before grouping the axe under
it, the axe's animation will change and yield undesirable results.
The preceding steps should give you an animation similar to
axe_v6.mb
in the Axe
project on the CD.
Motion Trails
You can see a moving object's trajectory, or
motion trail
—that is, its path of motion.
Follow these steps:
1. Select the axe through its selection handle, and then choose Animate
➔
Create
Motion Trail
r
. (See Figure 8.27.)
Figure 8.27
The Motion Trail
Options window
2. Select Line for Draw Style,
and make sure the Show
Frame Numbers check box is
checked.
3. Click Apply, and then click
Close to close the window.
The motion trail is useful for
fine-tuning motion. Editing
the animation curves in the
Graph Editor and watching
the motion trail adjust in the
work panels shows you the precise trajectory of the axe throughout its movement.
Play back your animation a few times to get a good sense of how the scene looks.
4. Select the axe, and open the Graph Editor.
5. Try adding more arc to the axe in the middle of its trajectory to the target.
6. In the Graph Editor, focus on the Translate Y curve, and select the keyframe at
frame 19.
7. Move the keyframe up about 2 units, and watch the motion trail adjust to show you
the higher arc.
8. Replay the animation with the higher arc in the middle.
