Plateau Interpolation

When you start animating a character where the feet need to be locked to the ground for periods of time, you'll find that Plateau interpolation is a perfect choice to begin animating with. During a walk cycle for example, a characters foot stays planted when it is the leading foot in a stride. The leading foot stays planted long enough for the rest of the body of the actor to pass it before the trailing foot now becomes the leading foot as it plants for the character to begin the next stride.

 

Softimage defaults to a spline type animation interpolation when you first launch the program. A spline interpolation always causes an ease in ease out interpolation between consecutive keysframes. Even if you keyframe a characters foot to be in the same position for two consecutive keys, such as in a foot strike, the spline interpolation will still cause the foot to drift, breaking the illusion of weight needed to make the character integrate into the scene.

To set the default interpolation to Plateau, click on File>User Preferences. In the pop up window that appears, click on the Animation Tab. Check the Plateau (Horizontal for local min and max) box, and then press OK. The next time you launch XSI, it will store this preference.

by Adam Sale