Torus Knot

Torus Knot creates a complex or knotted torus by drawing 2D curves in the normal planes around a 3D curve. The 3D curve (called the Base Curve) can be either a circle or a torus knot.

• Create panel > (Geometry) > Extended Primitives > Object Type rollout > Torus Knot button
• Default menu: Create menu > Extended Primitives > Torus Knot
• Alt menu: Objects menu > Extended Primitives > Torus Knot

You can convert a torus knot object to a NURBS surface.

Example of torus knot

Procedures

To create a Torus Knot:

1. On the Create menu, choose Extended Primitives Torus Knot.
2. Drag the mouse to define the size of the torus knot.
3. Click, then move the mouse vertically to define the radius.
4. Click again to finish the torus.
5. Adjust the parameters on the Modify panel.

Interface

Creation Method rollout

Diameter

Draws the object from edge to edge. You can change the center location by moving the mouse.

Radius

Draws the object from the center out.

Parameters rollout

Base Curve group

Provides parameters that affect the base curve.

Knot/Circle

With Knot, the torus interweaves itself, based on various other parameters. With Circle, the base curve is a circle, resulting in a standard torus if parameters such as Warp and Eccentricity are left at their defaults.

Radius

Sets the radius of the base curve.

Segments

Sets the number of segments around the perimeter of the torus.

P and Q

Describes up-and-down (P) and around-the-center (Q) winding numbers. (Active only when Knot is chosen.)

Warp Count

Sets the number of "points" in a star shape around the curve. (Active only when Circle is chosen.)

Warp Height

Sets the height of the "points" given as a percentage of the base curve radius.

Cross Section group

Provides parameters that affect the cross section of the torus knot.

Radius

Sets the radius of the cross section.

Sides

Sets the number of sides around the cross section.

Eccentricity

Sets the ratio of the major to minor axes of the cross section. A value of 1 provides a circular cross section, while other values create elliptical cross sections.

Twist

Sets the number of times the cross section twists around the base curve.

Lumps

Sets the number of bulges in the torus knot. Note that the Lump Height spinner value must be greater than 0 to see any effect.

Lump Height

Sets the height of the lumps, as a percentage of the radius of the cross section. Note that the Lumps spinner must be greater than 0 to see any effect.

Lump Offset

Sets the offset of the start of the lumps, measured in degrees. The purpose of this value is to animate the lumps around the torus.

Smooth group

Provides options to alter the smoothing displayed or rendered of the torus knot. This smoothing does not displace or tesselate the geometry, it only adds the smoothing group information.

• All Smoothes the entire torus knot.
• Sides Smoothes only the adjacent sides of the torus knot.
• None The torus knot is faceted.

Mapping Coordinates group

Provides methods of assigning and adjusting mapping coordinates.

Generate Mapping Coords

Assigns mapping coordinates based on the geometry of the torus knot. Default=on.

Offset U/V

Offset the mapping coordinates along U and V.

Tiling U/V

Tile the mapping coordinates along U and V.