+input mp-solid
+
+nb:=8;
+unit:=0.8;
+xm:=6;
+
+figureespace(-10u,-10u,10u,10u);
+Initialisation(1000,20,45,37.5);
+for k=-xm upto xm:
+ draw Projette((k,-xm,0))--Projette((k,xm,0));
+ draw Projette((-xm,k,0))--Projette((xm,k,0));
+endfor;
+r:=1; q:=4;
+arcenciel:=true;
+draw Tuben("(r*((q+1)*cos(t)-cos((q+1)*t)),r*((q+1)*sin(t)-sin((q+1)*t)),0.5)","(r*(-(q+1)*sin(t)+(q+1)*sin((q+1)*t)),r*((q+1)*cos(t)-(q+1)*cos((q+1)*t)),0)",0.5,0,102,0.06283);
+finespace;
+
+figureespace(-10u,-10u,10u,10u);
+Initialisation(1000,20,45,37.5);
+for k=-xm upto xm:
+ draw Projette((k,-xm,0))--Projette((k,xm,0));
+ draw Projette((-xm,k,0))--Projette((xm,k,0));
+endfor;
+r:=1; q:=4;
+Lumiere:=(0,0,3);
+arcenciel:=true;
+draw Tuben("(r*((q+1)*cos(t)-cos((q+1)*t)),r*((q+1)*sin(t)-sin((q+1)*t)),0.5)","(r*(-(q+1)*sin(t)+(q+1)*sin((q+1)*t)),r*((q+1)*cos(t)-(q+1)*cos((q+1)*t)),0)",0.5,0,102,0.06283);
+finespace;
+
+figureespace(-10u,-10u,10u,10u);
+Initialisation(1000,20,45,37.5);
+for k=-xm upto xm:
+ draw Projette((k,-xm,0))--Projette((k,xm,0));
+ draw Projette((-xm,k,0))--Projette((xm,k,0));
+endfor;
+r:=1; q:=4;
+Lumiere:=(0,0,10);
+arcenciel:=true;
+draw Tuben("(r*((q+1)*cos(t)-cos((q+1)*t)),r*((q+1)*sin(t)-sin((q+1)*t)),0.5)","(r*(-(q+1)*sin(t)+(q+1)*sin((q+1)*t)),r*((q+1)*cos(t)-(q+1)*cos((q+1)*t)),0)",0.5,0,102,0.06283);
+finespace;
+
+end