3ds Max 2012 Bible - Kelly L. Murdock [404]
3. Right-click over the white piece, and choose Curve Editor to open the Track View–Curve Editor. The white piece's X, Y, and Z Position tracks should be highlighted, and you should be able to see the function curves in the graph editor. If not, find them by choosing Objects⇒White Piece⇒Transform⇒Position⇒X, Y and Z Position.
Keeping in mind that RGB (red, green, blue) = XYZ, you can see the white checker's movement across the board. From 0 to 25, it moves only in the X direction. From 25 to 100, it moves diagonally across the board as indicated by the slope of both the X and Y curves. Note that when the object goes back the other way in the X direction at frame 75, the curve goes in the opposite direction, as shown in Figure 37.26.
FIGURE 37.26
The blocked-in animation curves for the white piece
4. Click the Play button.
The white piece slides sloppily around the board. Next, you create keys to make it hop over the red pieces.
5. Click the Insert Keys button, or select Insert Keys from the right-click menu. Click to insert keys on the Z-position track between the second, third, fourth, and fifth keys.
6. Select Move Keys Vertical from the Move Keys flyout, and select the three new keys. Move them up about 50 units, as shown in Figure 37.27.
FIGURE 37.27
The new keys are moved up.
The white piece hops over the red pieces, but the motion is not correct. The In and Out tangents should be fast so the piece does not spend much time on the board.
7. With the new keys still selected, hold the Shift key down, and move the handles on the keys to make them discontinuous tangent types, as shown in Figure 37.28.
FIGURE 37.28
The In and Out tangents corrected for the new keys
The hopping looks better, but the sliding motion would look better with a slight pause before hopping over the first red piece.
8. Select Move Keys Horizontal from the Move Keys flyout, and choose the second X-position track key. Hold down the Shift key, and move the key a few frames to the left to make a copy of the original key. Click the play button.
The red pieces should disappear as the white piece hops over them.
9. Scroll down the Controller pane on the left, and select the three red pieces. Under Tracks on the menu bar, choose Visibility⇒Add.
A visibility track has been added to each of the red pieces, directly below the root name.
With visibility, a value of 0 is invisible, and a value of 1 is visible. You could change the tangent types to Stepped to turn the red pieces invisible from one frame to the next, but changing the entire track to an On/Off controller helps to visualize what is happening.
10. Select the visibility track for Red Piece 01. Right-click, and choose Assign Controller. Choose On/Off.
Nothing seems to have happened. The Off/On controller is best used in Dope Sheet mode.
11. Choose Dope Sheet from the Modes menu. The On/Off controller track is represented with a blue bar. Blue indicates “on” or visible. Click the Insert Keys button, and click to add a key at frame 50. The blue bar stops at the key at frame 50. Click Play.
The first red piece disappears at frame 50. You can copy and paste tracks to save yourself a bit of work.
12. Select Red Piece 01's visibility track in the Controller pane. Right-click, and choose Copy. Select the visibility tracks for Red Piece 02 and Red Piece 03 (hold down the Ctrl key to add to the selection). Right-click, and choose Paste.
Paste as a Copy because the other pieces should disappear at different times.
13. Move Red Piece 02's key to 75 and Red Piece 03's key to 100. Click Play.
Things are looking pretty good, but the animation would look better if the whole thing were faster.
14. Click the Edit Ranges button and the Modify Subtree button. A World track bar appears at the top of the Key Pane. Click and drag the rightmost end of the range bar to frame 75 to scale all the tracks at one time. Click Play.
The animation is quite respectable as the white piece slides into the correct square and