本图片使用POV-Ray创作.

我，本作品著作权人，释出本作品至公有领域。这适用于全世界。 在一些国家这可能不合法；如果是这样的话，那么： 我无条件地授予任何人以任何目的使用本作品的权利，除非这些条件是法律规定所必需的。

This image was created using POV-Ray for Windows, version 3.6. The image was rendered to an 1800 x 1800 square, using 0.3 anti-aliasing.

#include "colors.inc"

background { color White }

global_settings { assumed_gamma 1.0}

camera
  {
  location <0, 0, -25>
  right <1,0,0> up <0,1,0>
  look_at  <0, 0, 0>
  angle 5
  }


light_source
  {
  <0, 20, -50>
  color White
  area_light <5, 0, 0>, <0, 5, 0>, 10, 10  /* very slow, decrease 10 to 2 for experiments */
  adaptive 3
  }


#declare r_tube = 0.07;  // thickness (radius) of tube

sphere_sweep
  {
  cubic_spline 99,
  <-0.649812,-0.501844,-0.00628982>, r_tube
  <-0.598897,-0.585324,0.0434712>, r_tube
  <-0.531952,-0.656315,0.0935696>, r_tube
  <-0.450457,-0.711121,0.142449>, r_tube
  <-0.356796,-0.746318,0.187515>, r_tube
  <-0.254408,-0.759313,0.225008>, r_tube
  <-0.148012,-0.748743,0.250271>, r_tube
  <-0.0437436,-0.714882,0.258363>, r_tube
  < 0.0507726,-0.660076,0.245122>, r_tube
  < 0.127003,-0.589085,0.20868>, r_tube
  < 0.177283,-0.508717,0.150801>, r_tube
  < 0.196969,-0.42612,0.0772678>, r_tube
  < 0.184584,-0.346025,-0.00236031>, r_tube
  < 0.140698,-0.269301,-0.0746092>, r_tube
  < 0.0697978,-0.195081,-0.1238>, r_tube
  <-0.0180266,-0.125128,-0.137702>, r_tube
  <-0.110105,-0.0648102,-0.113088>, r_tube
  <-0.196853,-0.0183172,-0.0569588>, r_tube
  <-0.27687,0.0170097,0.0167038>, r_tube
  <-0.356472,0.0512731,0.0917539>, r_tube
  <-0.441353,0.0960672,0.153252>, r_tube
  <-0.529177,0.157863,0.189655>, r_tube
  <-0.610439,0.236389,0.194648>, r_tube
  <-0.673338,0.326379,0.167842>, r_tube
  <-0.707627,0.419715,0.114164>, r_tube
  <-0.706706,0.507203,0.0426153>, r_tube
  <-0.668591,0.579983,-0.0351194>, r_tube
  <-0.596368,0.630847,-0.105955>, r_tube
  <-0.498091,0.655578,-0.156909>, r_tube
  <-0.386054,0.654398,-0.177062>, r_tube
  <-0.274756,0.633233,-0.159788>, r_tube
  <-0.17666,0.604118,-0.105177>, r_tube
  <-0.0961244,0.583044,-0.0217226>, r_tube
  <-0.0254188,0.583433,0.0740516>, r_tube
  <0.0505781,0.607736,0.161409>, r_tube
  <0.14263,0.645553,0.222025>, r_tube
  <0.249804,0.680582,0.245161>, r_tube
  <0.361582,0.698362,0.229028>, r_tube
  <0.463814,0.689958,0.179462>, r_tube
  <0.543481,0.652582,0.107446>, r_tube
  <0.591297,0.588672,0.0266508>, r_tube
  <0.602878,0.504609,-0.0486976>, r_tube
  <0.57912,0.409431,-0.105605>, r_tube
  <0.526,0.313346,-0.133941>, r_tube
  <0.453699,0.226066,-0.128157>, r_tube
  <0.374382,0.154595,-0.0888359>, r_tube
  <0.297918,0.100113,-0.0233438>, r_tube
  <0.22681,0.0552804,0.0553247>, r_tube
  <0.155962,0.00666063,0.131075>, r_tube
  <0.0803414,-0.0562119,0.187217>, r_tube
  <0.00216576,-0.134011,0.209731>, r_tube
  <-0.0693958,-0.219255,0.191886>, r_tube
  <-0.122645,-0.302968,0.13717>, r_tube
  <-0.148194,-0.380547,0.0578147>, r_tube
  <-0.142034,-0.45207,-0.0305414>, r_tube
  <-0.104372,-0.517835,-0.114177>, r_tube
  <-0.0378688,-0.575234,-0.183054>, r_tube
  <0.0517064,-0.619925,-0.230571>, r_tube
  <0.155871,-0.648106,-0.253798>, r_tube
  <0.265626,-0.657456,-0.253358>, r_tube
  <0.373098,-0.647055,-0.232348>, r_tube
  <0.472011,-0.617084,-0.195128>, r_tube
  <0.557591,-0.568763,-0.146313>, r_tube
  <0.626378,-0.50436,-0.0902236>, r_tube
  <0.676204,-0.42704,-0.0305544>, r_tube
  <0.706148,-0.340396,0.0297244>, r_tube
  <0.716316,-0.247877,0.0880708>, r_tube
  <0.707497,-0.152297,0.141943>, r_tube
  <0.680769,-0.0557321,0.188203>, r_tube
  <0.637336,0.0401719,0.222583>, r_tube
  <0.579081,0.133456,0.239585>, r_tube
  <0.509737,0.22128,0.233295>, r_tube
  <0.436165,0.300779,0.199485>, r_tube
  <0.368222,0.372431,0.138934>, r_tube
  <0.314713,0.443993,0.0613033>, r_tube
  <0.275482,0.526785,-0.0144342>, r_tube
  <0.238586,0.624245,-0.0678395>, r_tube
  <0.189551,0.726556,-0.0870203>, r_tube
  <0.121543,0.81652,-0.0712503>, r_tube
  <0.0366367,0.877849,-0.0279736>, r_tube
  <-0.0575034,0.899793,0.0307359>, r_tube
  <-0.150878,0.878602,0.090885>, r_tube
  <-0.233567,0.81761,0.138454>, r_tube
  <-0.297931,0.726789,0.16115>, r_tube
  <-0.341299,0.621392,0.150632>, r_tube
  <-0.368896,0.518174,0.105306>, r_tube
  <-0.393939,0.428301,0.0331611>, r_tube
  <-0.430147,0.350877,-0.0486069>, r_tube
  <-0.481452,0.27536,-0.120778>, r_tube
  <-0.541173,0.192166,-0.170682>, r_tube
  <-0.599286,0.0990371,-0.194272>, r_tube
  <-0.647828,-0.00118549,-0.193649>, r_tube
  <-0.682117,-0.104702,-0.174067>, r_tube
  <-0.699975,-0.208608,-0.141333>, r_tube
  <-0.700611,-0.310814,-0.100365>, r_tube
  <-0.683855,-0.409351,-0.0546503>, r_tube
  <-0.649812,-0.501844,-0.00628982>, r_tube
  <-0.598897,-0.585324,0.0434712>, r_tube
  <-0.531952,-0.656315,0.0935696>, r_tube
  pigment { color rgb <0,0.25,1> }
  finish          
    {
    ambient 0.15
    diffuse 0.85
    brilliance 2
    phong 0.25
    phong_size 7.5
    }
  }

plane
  {
  <0,0,-1>, -0.33
  pigment { color White }
  finish
    {
    ambient 0.35
    diffuse 0.65
    }
  }