public static Vector3f interpolateLinear(float scale, Vector3f startValue,
            Vector3f endValue, Vector3f store) {
        if (store == null) {
            store = new Vector3f();
        }
        store.x = interpolateLinear(scale, startValue.x, endValue.x);
        store.y = interpolateLinear(scale, startValue.y, endValue.y);
        store.z = interpolateLinear(scale, startValue.z, endValue.z);
        return store;
    }
Linear interpolation from startValue to endValue by the given percent.
Basically: ((1 - percent) * startValue) + (percent * endValue)

@param scale
           scale value to use. if 1, use endValue, if 0, use startValue.
@param startValue
           Beginning value. 0% of f
@param endValue
           ending value. 100% of f
@param store a vector3f to store the result
@return The interpolated value between startValue and endValue.
jme3-core/src/main/java/com/jme3/math/FastMath.java