public Vector3f interpolateLocal(Vector3f beginVec, Vector3f finalVec, float changeAmount) {
        this.x = (1 - changeAmount) * beginVec.x + changeAmount * finalVec.x;
        this.y = (1 - changeAmount) * beginVec.y + changeAmount * finalVec.y;
        this.z = (1 - changeAmount) * beginVec.z + changeAmount * finalVec.z;
        return this;
    }
Interpolates linearly between the specified beginning and final vectors,
returning the (modified) current instance.

<p>this = (1 - changeAmount) * beginVec + changeAmount * finalVec

@param beginVec the desired value when changeAmount=0 (not null, unaffected
    unless it's <code>this</code>)
@param finalVec the desired value when changeAmount=1 (not null, unaffected
    unless it's <code>this</code>)
@param changeAmount the fractional change amount
@return the (modified) current instance (for chaining)
jme3-core/src/main/java/com/jme3/math/Vector3f.java