Figure Asymptote solids -- 009

Posted on 2011-01-01 Edited on 2025-06-30 In EN , Tech , Programming , Asymptote , Examples 3D , Solids.asy

An Asymptote code and the generated picture solids--009.

🔗This picture comes from the Asymptote gallery of topic solids

Figure solids 009 Generated with Asymptote

size(8cm, 0);
import solids;
import graph3;

//Draw 3D right angle (MA, MB)
void drawrightangle(picture pic=currentpicture,
                    triple M, triple A, triple B,
                    real radius=0,
                    pen p=currentpen,
                    pen fillpen=nullpen,
                    projection P=currentprojection)
{
  p=linejoin(0)+linecap(0)+p;
  if (radius==0) radius=arrowfactor*sqrt(2);
  transform3 T=shift(-M);
  triple OA=radius/sqrt(2)*unit(T*A),
    OB=radius/sqrt(2)*unit(T*B),
    OC=OA+OB;
  path3 tp=OA--OC--OB;
  picture tpic;
  draw(tpic, tp, p=p);
  if (fillpen!=nullpen) draw(tpic, surface(O--tp--cycle), fillpen);
  add(pic, tpic, M);
}

currentprojection=orthographic(10, 15, 3);

real r=10, h=6; // r=sphere radius; h=altitude section
triple Op=(0, 0, h);

limits((0, 0, 0), 1.1*(r, r, r));
axes3("x", "y", "z");

real rs=sqrt(r^2-h^2); // section radius
real ch=180*acos(h/r)/pi;
path3 arcD=Arc(O, r, 180, 0, ch, 0, Y, 50);

revolution sphereD=revolution(O, arcD, Z);
draw(surface(sphereD), opacity(0.5)+lightblue);
draw(shift(0, 0, h)*scale3(rs)*surface(unitcircle3), opacity(0.5));

path3 arcU=Arc(O, r, ch, 0, 0, 0, Y, 10);
revolution sphereU=revolution(O, arcU, Z);
draw(surface(sphereU), opacity(0.33)+lightgrey);

// right triangle OO'A
triple A=rotate(100, Z)*(rs, 0, h);
dot("$O$", O, NW);
dot("$O'$", Op, W);
dot("$A$", A, N);
draw(A--O--Op--A);
drawrightangle(Op, O, A);

if(!is3D())
  shipout(format="pdf", bbox(Fill(paleyellow)));