//Zheng.bvr\n\n// Parametric curve\n\nhelix=parametricCurve\n\nhelix.setMinMax=t,0,6.28\n\nhelix.setEquation=x,(3)\n\nhelix.setEquation=y,(7^(1/2)*sin(t))\n\nhelix.setEquation=z,(7^(1/2)*cos(t))\n\nhelix.setSegmentCount=70\n\nhelix.setThickness=0.2\n\nhelix.color=red\n\nhelix.spawn\n\n \n\n// Parametric surface\n\ncyl=parametricSurface\n\ncyl.setMinMax=s,0,6.28\n\ncyl.setMinMax=t,0,3.14\n\ncyl.setEquation=x,(4*cos(t)*sin(s))\n\ncyl.setEquation=y,(4*sin(t)*sin(s))\n\ncyl.setEquation=z,(4*cos(s))\n\ncyl.setSegmentCount=50\n\ncyl.color=blue\n\ncyl.spawn \n\n// Parametric surface\n\npl=parametricSurface\n\npl.setMinMax=s,-6.28,6.28\n\npl.setMinMax=t,-3.14,3.14\n\npl.setEquation=x,(3) \n\npl.setEquation=y,(s)\n\npl.setEquation=z,(t)\n\npl.setSegmentCount=50\n\npl.color=green \n\npl.spawn\n\n