Graphics Programs Reference
In-Depth Information
Figure 14.44
then select “Insert Keyframe” (Figure 14.44).
The bar will turn yellow and a vertical yellow
line is added in the timeline window under the
green cursor to show that a key frame has been
set at frame 25. In the timeline window, move
the green cursor to frame 125. In the proper-
ties window - “Path Animation” tab, change
the “Evaluation Time” value to 100. The cube
moves along the path as you drag the mouse.
At “Evaluation Time: 100,” the cube is at the
end of the path. Repeat the process for adding
a key frame.
14.8.3 Timeline Animation Play Control Buttons
In the timeline window, return to frame 1 and play the animation (press Esc to stop the ani-
mation). Consult Figure 14.45 for an explanation of the timeline animation control buttons.
The animation plays but the cube remains stationary until frame 25, then it moves along the
path and reaches the end at frame 125. The animation continues to play in the timeline until
frame 250. In the 3D window, carefully observe the motion of the cube as it moves along the
path. At the start, there is a definite acceleration followed by a constant velocity then a de-
celeration as the cube approaches the end of the path. We can see a graphical representation
of this movement in the graph editor window. Divide the 3D window in two and change
one half to the graph editor window; you will probably have to zoom in on the window
(press the number pad - key several times or scroll the MMB) and also drag the window to
centralize the graph (hold and drag the MMB). Scale the graph horizontally and vertically
by holding Ctrl + the MMB and dragging the mouse (Figure 14.46).
Figure 14.45
Go to the last frame in the animation.
Go to the next key frame.
Play the animation forward.
Play the animation back.
Go to the previous key frame.
Go to the first frame in the animation.
