Tube

TUBE (FN fn) [using] [color Ex RGBCOLOR] [width Ex thickness] [in ST window name]

Syntax

make f(s) [s, 2*s, s^2];

Draw the Tube f using color red in "my3Dwin";

Use Curvedomain, and Curverefinement

            Creates a Space Curve actor whose name is the name of the first variable: FN.  A space curve is created from a function of the form:  t ->[x(t), y(t), z(t)] mapping an interval to the scene. These are created as hollow "tubes" (with any desired thickness) when the curve is differentiable and satsfies the regularity condition: the velocity and curvature do not vanish. 

You may set the domain and drawing refinement either with the Curvedomain, and Curverefinement commands or directly from the Actors, create tube actor menu. Once you create the actor with this command, you may define a script for it (say to change its color) in the Actor, Edit Script Menu. And you may save a collection of curves permanently to a scene file using the Save Scene File As... menu.

The default domain for tubes is initially [0, 2*pi], otherwise the most recently used. Tubes have two types of refinement, the angular refinement and ordinary refinement. Angular refinement is the refinement in the "girth" direction orthogonal to the curve. And each tube is drawn with a "thickness" or "width". The default values are: Refinement 25, Angular Refinement 10, Thickness 0.1. These may all be changed in the Actors, create tube actor menu Dialog Box.