Two-Dimensional
Texture domain HyperGraph Table of
Contents. 
HyperGraph Home page. We can define a torus by the equations:
[Note: p = Pi = 3.141592. Define q as the angle from the X axis (0 <= q <= 2p) and f as the angle from the Z axis (0.0 <= f <= p).]
Then, with R as the inner radius and r as the outer radius:
X = (R + r cos (2 pv)) cos (2 pu)
Y = r sin (2 pv)
Z = (R + r cos (2 pv)) sin (2 pu)
Then:
v = arccos (Y/R)/2p
u = [arccos ((X/(R + r*cos(2 pv))]2p
Two-Dimensional
Texture domain
HyperGraph Table of
Contents.
HyperGraph Home page.