Processing: Creative Coding and Computational Art

1. Generate a circle (actually a polygon) on the xy plane at the origin (0, 0).
2. Displace the circle on the x-axis the distance of the toroid radius.
3. Copy (lathe) the circle elliptically around the y-axis, maintaining the toroid radius
distance from the origin.
Toroids have a ring thickness, which relates to the initial diameter of the lathed circle, and
an inner hole diameter based on the distance of the lathed circle from the origin. The initial
circle, which you’ll be lathing with, will actually be a polygon with a lot of points (like
in the preceding cylinder example). Finally, the lathing will be controlled by a segment
level, which determines how many copies of the circle are rotated around the y-axis. The
lathe segments will be evenly spaced, and will determine the smoothness of the toroid.
The really cool thing is that you can easily control all these properties in real time, interactively
revealing a wide range of interesting 3D forms based on your initial algorithm. The
following sketch includes a bunch of key commands, which are listed at the top of the program
as a code comment. The sketch requires the Point3D class, but not the Cube class.
/* Interactive Toroid
Point3D class required
****************************************
key command controls
******************
UP arrow key pts++;
DOWN arrow key pts--;
LEFT arrow key segments--;
RIGHT arrow key segments++;
'a' key toroid radius--;
's' key toroid radius++;
'z' key initial polygon radius--;
'x' key initial polygon radius++;
'w' key toggle wireframe/solid shading
'h' key toggle sphere/helix
****************************************/
//ellipse (shape to lathe)
int pts = 40;
float angle = 0;
float radius = 40.0;
// lathe segments
int segments = 60;
float latheAngle = 0;
float latheRadius = 100.0;
//vertices
Point3D vertices[], vertices2[];
// for shaded or wireframe rendering
boolean isWireFrame = false;
// for optional helix
boolean isHelix = false;
float helixOffset = 5.0;
3D
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