import solids; size(7.5cm,0); currentprojection=orthographic(3,9,2); currentlight=White; revolution sph=sphere(O,1); real a=.7; //compris entre 0 et 1 real b=2.4; draw(surface(shift(-b/2,-b/2,sin(pi*(a-.5)))*scale3(b)*unitsquare3),white+opacity(.7)); draw(surface(sph),orange); skeleton s; sph.transverse(s,reltime(sph.g,a),P=currentprojection); draw(s.transverse.back,linetype("8 8",8)); draw(s.transverse.front);