CenterStageObject Class: SurfaceFromCurve Subclass of: Surface Requires reference to a Curve object The SurfaceFromCurve lets you create a Surface object that relates to an existing curve object. The second parameter for the surface is used as the parameter for the curve, and at each value of the parameter, the curve function is evaluated. Then for each value of the other parameter, the surface function is computed, and the two are added, either in aboslute coordinates, or in terms of the Frenet frame of the curve. In addition to the standard Surface directives, SurfaceFromCurve supports the following: Function params func [vfunc] [-frame | -absolute] Here the "params", "func" and "vfunc" arguments are the same as for the standard Surface. The -frame and -absolute options determine whether the result of the function is in the coordinate system of the Frenet frame for the reference curve or in absolute coordinates (the default). If -frame is provided, then both the surface and the curve must be in 3-space, and the Frenet frame is computed numerically. The x, y and z coordinates correspond to the tangent, normal and binormal directions for the curve. If only one of the parameters is specified, the second is taken from the reference curve. For example: Function {s} { let (T,N,B) = r (0,cos s,sin s) } -frame Axes {T N B} Slider r 0 2 .1 produces a circular tube centered around the reference curve. The radius is controlled by a slider, so it is easy to investigate the family of tubes around the curve. Domain {{umin umax udivs} {Inherit}} This special form of the domain command can be used to inherit the domain from the original curve. Standard Domain specifications can also be used to provide a domain other than the one of the original curve.