Tennis Ball in ASY-3D.pdf of Bruno-Colombel
by Klaus-Anton, May 24, 2024, 12:26 PM
You have seen perhaps A Tennis-Ball Curve on a Sphere. And therefore it can be clear for you that here the things are not only of interest which appear on the surface of the sphere but too those which are happening inside of the sphere.
code - click me

Figure 1: png of Tennis Ball in ASY-3D.pdf (of Bruno-Colombel, modified)
code - click me
// http://asymptote.ualberta.ca/ //Here you can compile it online. // Render as html, download it. // Right mouse botton on your html-download to be able to save it you as png. // la ball de tennis ASY-3D (Bruno Colombel), page 59, code 87 //la-ball-de-tennis-ASY-3D-Bruno-Colombel-page-59-code-87-2024-05-24-14h02 // [img]https://i.imgur.com/dRG1tqB.png[/img] import graph3; currentprojection= orthographic(camera=(1.6191296713072574,-1.7133853186013346,4.87950530609615), up=(0.014789545994134843,-0.007578532857513608,-0.007568634537649142), target=(0,0,-3.330669e-16), zoom=1); size(6cm,0); real a=1; real b=0.5; real c=2*sqrt(a*b); real x(real t) {return a*cos(t) + b*cos(3*t);} real y(real t) {return a*sin(t) - b*sin(3*t);} real z(real t) {return c*sin(2*t);} draw(scale3(a+b)*unitsphere, lightyellow+opacity(0.5), nolight); path3 s=graph(x,y,z,0,2*pi)--cycle; draw(s,white+linewidth(10pt)); draw(surface(s),black+opacity(.2),nolight);