The Barycentric Morph controller is automatically applied when you create a morph objectMorph compound object. Morph targets are selected and keys are created at different times to change the original object's shape to those of the morph targets.
The Barycentric Morph controller represents each key as a series of weights for all targets. One barycentric key represents a new object which is a blending of all targets.
You can adjust each morph key to various percentages of the available morph targets. This lets you create subtle adjustments in the animation.
You can insert keys between existing morph keys. These added keys contain interpolated values for all targets.
To access the key properties dialog, select the Morph track, select one of its keys, and click Properties to display the Key Info dialog.
After assigning the Barycentric Morph controller in Create panel 
Compound Objects Morph, then morph parameters for the controller display in the Modify panel and in the Barycentric Controller Key Info dialog,
which is displayed by right-clicking over a morph key in Track View Dope Sheet or the track bar.
See Morph Compound Object for Morph parameters.
You can change morph target weighting using controls in the Barycentric Morph Controller Key Info dialog.
Create panel