Autodesk 12812-051462-9011 User Guide 3 - Page 2888

Tangents The tangent of a function curve affects the interpolated values between the keys of an animation. Most animation controllers use fixed tangents to define the function curve at a key location. By default, 3ds Max assigns smooth tangents to the keys in a Position function curve. This is the reason that an animated object moves in smooth curves through the key frames. 3ds Max assigns smooth tangents because they usually provide the most natural motion. Of course, you also need a way to add some corners and abrupt turns when you need them. The Linear controller on page 3193 uses a discontinuous tangent that points at the preceding and following keys, producing an abrupt change in motion at that key. The two large flyout buttons at the bottom of the Key Info dialog provide five different types of predefined tangent types on page 3129, plus a sixth type that lets you create your own custom tangents. If you look at a single key dot and the line running through it, the line on the left side of the key dot is the incoming tangent, and the line on the right is the outgoing tangent. Using the tangent flyout buttons, you can assign a different tangent type to the incoming and the outgoing lines for each key dot. The button on the left assigns the incoming tangent at the left side of the selected key dot, and the button on the right assigns the outgoing tangent on the right side of the selected key dot. TCB (Biped) TCB is short for Tension, Continuity, and Bias. These parameters quantify the traditional animation technique of ease in and ease out (also known as "slow in and slow out"). In freeform animation on page 7988 of a biped, you can use them to change the timing of a limb's movement from key to key. The TCB controls are in the TCB section of the Key Info rollout on page 4367. Glossary | 8143