Bezier Controllers
 
 
 
Command entry:Main toolbar Curve Editor (Open) Select a track in the Track View hierarchy. Track View menu bar Controller menu Assign Bezier
Command entry:Graph Editors Track View   Curve Editor Select a track in the Track View hierarchy. Track View menu bar Controller menu Assign Bezier

The Bezier controller is the most versatile controller available in 3ds Max. Bezier controllers interpolate between keys using an adjustable spline curve. They are the default controller for most parameters.

Use Bezier controllers whenever you want fully adjustable interpolation between keys. Bezier is the only controller that supports the following:

Procedures

To set the tangent type for a key:

  1. Select an object that has some animation keys, and open the Motion panel Key Info (Basic) rollout.
  2. Use the arrows to select a key.
  3. Choose a tangent type from the In or Out tangent flyouts.

To normalize time for a key:

  1. Select an object, and then choose a key to normalize.

    You can use the arrows in the Key Info (Basic) rollout to step through keyframes.

  2. On the Motion panel Key Info (Advanced) rollout, click Normalize Time.

    The key is moved in time to average the velocity through the key.

Interface

Motion panel > Parameters > Key Info (Basic) rollout

A Key Info dialog with identical parameters to this rollout is available by right-clicking a key in Track View or the track bar.

Key number

Shows the current key number. Click the right or left arrows to go to the next or previous key.

Time

Specifies when in time the key occurs.

Time Lock

Controls dragging the key horizontally in Track View edit modes.

X/Y/Z

Adjusts the position of the selected object at the current key.

Key Tangent

Two flyouts set the interpolation properties of the in tangent and out tangent of the key.

Choosing Bezier Tangent Types

Sets the tangent types for one or more keys in the same track using the In and Out tangent flyouts.

See Tangent Types for detailed information on each of the available tangent choices.

Tangent Copy

Copies the tangent type between the tangents of the current key or between the tangents of the previous and next key. Use the arrow buttons on either side of the Key Tangent flyouts.

The left arrow of the In tangent copies to the Out tangent of the previous key.

The right arrow of the In tangent copies to the Out tangent of the current key.

The left arrow of the Out tangent copies to the In tangent of the current key.

The right arrow of the Out tangent copies to the In tangent of the next key.

Choosing Bezier Tangent Types

Sets the tangent types for one or more keys in the same track using the In and Out tangent flyouts.

Bezier Scale Controller (Lock X)

Causes the X value to affect all three axes of scale. The Y and Z values are ignored and their function curves are not displayed.

When X is locked, the Y and Z values are not affected by changes in the X value. If you lock X when all three axes are at identical values, alter the X value, and then unlock X, the Y and Z values remain where they were while X retains its new value.

Motion panel > Parameters > Key Info (Advanced) rollout

Controls in the rollout affect velocity in three ways:

  • Control the absolute velocity at a key using the In/Out values
  • Average velocity over a specified amount of time using Normalize Time
  • Force constant velocity from one component key to the next using Constant Velocity
In/Out

The In field displays the rate of change as the parameter approaches the key. The Out field displays the rate of change as the parameter leaves the key.

These fields are active only for keys that use the Spline tangent type.

The number in the field is the rate of change expressed as parameter units per Tick. By changing the two values for X, Y, and Z you are changing the length and angle of the tangent handle.

Lock button

When on, changing one Spline tangent changes the other by equal but opposite amount. For example, if the Lock button is on and the In value is 0.85, then the Out value is -0.85.

Normalize Time

Averages the position of the keys in time and is applicable to any consecutive blocks of selected keys. Useful if you want to smooth out the motion and have an object that speeds up, slows down, speeds up, and slows down.

Constant Velocity

Interpolates values between a key and the next one in a way that makes the object move at a constant velocity across that curve segment.

Free Handle

Used for automatically updating the length of the tangent handle. When this is turned off, the length of the tangent is at a fixed percentage from its neighboring key. As you move a key, the handles adjust to stay the same percentage away from the neighboring keys. When this is turned on, the handle lengths are based on time lengths.

Create Position Lock Key / Create Rotation Lock Key

Sets both the incoming handle of the current key and the outgoing handle of the previous key to Linear interpolation. This prevents overshoot from the Spline interpolation.

To use these two features, first create a keyboard shortcut in Customize Customize User Interface. Look for Create Position Lock Key and Create Rotation Lock Key in the Action list and assign hotkeys. Or you can add these commands to a toolbar or a quad menu (Quads panel).