Definition of start tangent

#SET ASPLINE STARTTANG {<axis_name><expr>} (modal)

<axis_name> <expr> Components of the tangent vector

Using axis designations, a vector is specified whose direction corresponds to the direction of the tangent - the vector thus need not be normalized, however, always all the components must be specified.

For tracking axes the derivation regarding the curve parameter is specified, which corresponds to the ratio of movement of the tracking axis to the movement of the main axes.