3ds Max 2012 Bible - Kelly L. Murdock [395]
The Slide Keys button in the Dope Sheet lets you select a key and move all adjacent keys in unison to the left or right. If the selected key is moved to the right, all keys from that key to the end of the animation slide to the right. If the key is moved to the left, then all keys to the beginning of the animation slide to the left.
The Scale Keys button, also in the Dope Sheet, lets you move a group of keys closer together or farther apart. The scale center is the current frame. You can use the Shift key to clone keys while dragging.
If the Dope Sheet's Snap Frames button (keyboard shortcut S) is enabled, the selected key snaps to the nearest key as it is moved. This makes aligning keys to the same frame easy.
Using the Region tool
Within the Curve Editor, the Region tool is used to move, slide, and scale a set of selected keys. To use this tool, simply drag in the Key pane over the keys you want to select. A box is displayed around all the selected keys with handles at each edge, as shown in Figure 37.6. The selected keys can be moved to a different location by clicking within the region and dragging to a new location. You can drag the selected keys up or down to change their values or left and right to change their frame.
New Feature
The Region tool is new to 3ds Max 2012. •
FIGURE 37.6
The Region tool places handles around each side of the selected keys for sliding and scaling keys.
Dragging on either of the side handles scales the range of the selected keys, and dragging on the top or bottom handles scales their values. The side of the selected handle is the side of the region that moves during a scale operation, but if you press and hold the Shift key, the region is scaled equally from both sides. If you scale the region over any non-selected keys, those non-selected keys are simply deleted. The Region tool remains active until another tool, such as the Move tool is selected. If you click and drag outside of the selected region, a new region is selected.
Editing keys
To edit the key parameters for any controller, right-click the key in the Curve Editor or click the Properties button in the Dope Sheet; this opens the Key Info dialog box for most controllers. You also can access this dialog box by right-clicking a track and selecting Properties from the pop-up menu. These commands also can be used when multiple keys on the same or on different tracks are selected.
Using the Randomize Keys utility
The Randomize Keys utility lets you generate random time or key positions with an offset value. To access this utility, select the track of keys that you want to randomize and choose Utilities⇒Track View Utilities to open the Track View Utilities dialog box. From this dialog box, select Randomize Keys from the list of utilities and click OK; the Randomize Keys utility dialog box opens, as shown in Figure 37.7.
FIGURE 37.7
Use the Randomize Keys utility to create random key positions and values.
In this dialog box, you can specify positive and negative shift values for both Time and Value. Click the Apply button to apply the randomization process.
Using the Euler Filter utility
Euler rotations are easy to understand and use. They provide rotations about each of the three axes or can be thought of as yaw, pitch, and roll, but they have an inherit flaw—they are susceptible to Gimbal flipping and Gimbal lock. Gimbal flipping can occur when the rotation is directed straight up or straight down. This causes the object to instantly flip 180 degrees to continue its rotation. Gimbal lock can occur when two Euler rotation angles are aligned, causing the object to lose a degree of freedom.
To counter these problems, Max has the ability to use Quaternions instead of Euler angles. Quaternions are vector-based instead of angle-based, so they aren't susceptible to the Gimbal flipping and lock problems, but many animators find Quaternions difficult to understand and use, so they stick to Euler rotations and are watchful for potential problems.
The Track View has a utility that can help if you're dealing