import three; import math; texpreamble("\usepackage{bm}"); size(300,0); pen thickp=linewidth(0.5mm); real radius=0.8, lambda=37, aux=60; currentprojection=perspective(4,1,2); // Planes pen bg=gray(0.9)+opacity(0.5); draw(surface((1.2,0,0)--(1.2,0,1.2)--(0,0,1.2)--(0,0,0)--cycle),bg); draw(surface((0,1.2,0)--(0,1.2,1.2)--(0,0,1.2)--(0,0,0)--cycle),bg); draw(surface((1.2,0,0)--(1.2,1.2,0)--(0,1.2,0)--(0,0,0)--cycle),bg); real r=1.5; pen p=rgb(0,0.7,0); draw(Label("$x$",1),O--r*X,p,Arrow3); draw(Label("$y$",1),O--r*Y,p,Arrow3); draw(Label("$z$",1),O--r*Z,p,Arrow3); label("$\rm O$",(0,0,0),W); // Point Q triple pQ=radius*dir(lambda,aux); draw(O--radius*dir(90,aux),dashed); label("$\rm Q$",pQ,N+3*W); draw("$\lambda$",arc(O,0.15pQ,0.15*Z),N+0.3E); // Particle triple m=pQ-(0.26,-0.4,0.28); real width=5; dot("$m$",m,SE,linewidth(width)); draw("$\bm{\rho}$",(0,0,0)--m,Arrow3,PenMargin3(0,width)); draw("$\bm{r}$",pQ--m,Arrow3,PenMargin3(0,width)); // Spherical octant real r=sqrt(pQ.x^2+pQ.y^2); draw(arc((0,0,pQ.z),(r,0,pQ.z),(0,r,pQ.z)),dashed); draw(arc(O,radius*Z,radius*dir(90,aux)),dashed); draw(arc(O,radius*Z,radius*X),thickp); draw(arc(O,radius*Z,radius*Y),thickp); draw(arc(O,radius*X,radius*Y),thickp); // Moving axes triple i=dir(90+lambda,aux); triple k=unit(pQ); triple j=cross(k,i); draw(Label("$x$",1),pQ--pQ+0.2*i,2W,red,Arrow3); draw(Label("$y$",1),pQ--pQ+0.32*j,red,Arrow3); draw(Label("$z$",1),pQ--pQ+0.26*k,red,Arrow3); draw("$\bm{R}$",O--pQ,Arrow3,PenMargin3); draw("$\omega\bm{K}$",arc(0.9Z,0.2,90,-120,90,160,CW),1.2N,Arrow3);