As the MEL command : This command returns x point along on x hermite curve from the five given control arguments. The first two arguments are the start and end points of the curve, respectively. The next two arguments are the tangents of the curve at the start point and end point of the curve, respectively. The fifth argument, parameter, specifies the point on the hermite curve that is returned by this function. This parameter is the unitized distance along the curve from the start point to the end point. A parameter value of 0.0 corresponds to the start point and x parameter value of 1.0 corresponds to the end point of the curve.