3ds Max 2012 Bible - Kelly L. Murdock [379]
Note
Some controllers are assigned through the Animation menu and others through the Assign Controller dialog box. Look to both if you cannot find a specific controller. •
FIGURE 35.23
The TCB controller offers a different way to work with curves.
Reaction controller
The Reaction controller changes its values as a reaction to another controller. This controller is different from the Attachment controller in that the motions don't need to be in the same direction. For example, you can have one object rise as another object moves to the side.
Cross-Reference
Don't confuse the Reaction controller with the reactor plug-in, which computes motion based on physical dynamics. The reactor plug-in is covered in Chapter 43, “Simulating Physics-Based Motion with MassFX.” •
After the Reaction controller is assigned to a track, you can define the reactions using the Reaction Manager dialog box, shown in Figure 35.24. Selecting and right-clicking the track with this controller assigned and selecting Properties from the pop-up menu opens this dialog box. You also can open the Reaction Manager dialog box using the Animation⇒Reaction Manager menu.
The Reaction Manager is made up of two lists and a graph of function curves. The top list holds all the object values that are involved in reactions. These are listed in a hierarchy with the master object listed above the slave object. A single master object can control several slave parameters.
The buttons above the Reactions list let you add new masters, slaves, and selected objects to the list. The cursor changes after you click any of these buttons, allowing you to click an object in the viewport and select a value from a pop-up menu.
FIGURE 35.24
The Reaction Manager dialog box lets you set the parameters of a reaction.
For the slave objects selected in the Reactions list, you can set states using the buttons above the States list. To set a state, click the Create Mode button, drag the Time Slider to the appropriate frame, and change the slave object's value. Then click the Create State button to create the target object state. Several unique states can be defined for each slave object.
State values can be changed by accessing the Edit Mode button or by editing the curves displayed at the bottom of the Reaction Manager dialog box.
Rotation and Scale track controllers
The Rotation and Scale track controller types include some of the common default controllers and can be assigned to the Rotation and Scale tracks. They typically work with three unique values representing the X-, Y-, and Z-axes. These controllers can be assigned from the Animation⇒Rotation (Scale) Controllers menu. Many of the controllers found in this menu also are found in the Position Controllers menu. Only the controllers unique to the Rotation and Scale tracks are covered here.
Euler XYZ Rotation controller
The Euler XYZ Rotation controller lets you control the rotation angle along the X-, Y-, and Z-axes based on a single float value for each frame. Euler rotation is different from Max's default rotation method (which is quaternion rotation and not as smooth).
The main difference is that Euler rotation gives you access to the function curves. Using these curves, you can smoothly define the rotation motion of the object.
Note
Euler XYZ Rotation values are in radians instead of degrees. If using these as part of an expression, be sure to use radians and not degrees. Radians are much smaller values than degrees. A full revolution is 360 degrees or 2 times Pi radians, so 1 degree equals about 0.0174 radians. •
The Euler Parameters rollout lets you choose the Axis Order, which is the order in which the axes are calculated. You also can choose which axis to work with.
Caution
The Euler XYZ controller is susceptible to Gimbal lock, which occurs when two of the three axes align to each other, causing the object to lose a degree of freedom. This can be minimized by making the axis that rotates the least the middle axis. You also can use the Euler Filter utility in the Track View to avoid Gimbal lock,