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, and then cropped and compressed using pngcrush.
#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 89, <-0.738272,-0.137241,-0.116252>, r_tube <-0.771226,-0.252727,-0.0690456>, r_tube <-0.77771,-0.366515,-0.00940232>, r_tube <-0.755546,-0.475284,0.0552339>, r_tube <-0.703814,-0.574599,0.118119>, r_tube <-0.623356,-0.658636,0.172757>, r_tube <-0.517725,-0.720368,0.212752>, r_tube <-0.394263,-0.752361,0.232167>, r_tube <-0.265029,-0.748211,0.226395>, r_tube <-0.146703,-0.704844,0.193727>, r_tube <-0.0581259,-0.625177,0.136989>, r_tube <-0.0147325,-0.519015,0.0648827>, r_tube <-0.0228379,-0.398989,-0.00464281>, r_tube <-0.0753355,-0.276642,-0.0439511>, r_tube <-0.154445,-0.166394,-0.0327461>, r_tube <-0.243216,-0.0824995,0.0250816>, r_tube <-0.335515,-0.0238808,0.106357>, r_tube <-0.435166,0.0288372,0.182224>, r_tube <-0.542016,0.095717,0.228639>, r_tube <-0.642952,0.182997,0.23192>, r_tube <-0.718106,0.284775,0.19055>, r_tube <-0.749853,0.388915,0.114203>, r_tube <-0.728221,0.481278,0.0209964>, r_tube <-0.653625,0.549351,-0.0659591>, r_tube <-0.537853,0.585897,-0.122594>, r_tube <-0.402732,0.593276,-0.129428>, r_tube <-0.273576,0.587648,-0.0793947>, r_tube <-0.165144,0.597439,0.0128131>, r_tube <-0.0695384,0.644295,0.109002>, r_tube <0.0330574,0.719423,0.167919>, r_tube <0.15023,0.789973,0.170137>, r_tube <0.271358,0.824211,0.121141>, r_tube <0.378013,0.804887,0.0417334>, r_tube <0.453686,0.7309,-0.0407349>, r_tube <0.489596,0.615077,-0.0987829>, r_tube <0.488766,0.480137,-0.110572>, r_tube <0.468924,0.350877,-0.0669706>, r_tube <0.45877,0.240552,0.0203739>, r_tube <0.478728,0.141095,0.118936>, r_tube <0.52303,0.0347509,0.194051>, r_tube <0.570067,-0.0853008,0.227952>, r_tube <0.602009,-0.21198,0.219587>, r_tube <0.609933,-0.334119,0.176751>, r_tube <0.591479,-0.443186,0.110351>, r_tube <0.547813,-0.534603,0.0310731>, r_tube <0.481374,-0.606709,-0.0519399>, r_tube <0.394756,-0.65922,-0.130945>, r_tube <0.290617,-0.691979,-0.19885>, r_tube <0.172394,-0.704416,-0.24839>, r_tube <0.0457538,-0.69574,-0.271942>, r_tube <-0.0799134,-0.665782,-0.262449>, r_tube <-0.191017,-0.61641,-0.215554>, r_tube <-0.271592,-0.552941,-0.132515>, r_tube <-0.308397,-0.483869,-0.0220469>, r_tube <-0.294624,-0.416756,0.098757>, r_tube <-0.229936,-0.351835,0.202922>, r_tube <-0.126056,-0.286213,0.261528>, r_tube <-0.00693826,-0.224507,0.259725>, r_tube <0.104256,-0.176108,0.202779>, r_tube <0.198655,-0.144607,0.110623>, r_tube <0.28779,-0.122547,0.00897438>, r_tube <0.389646,-0.0958184,-0.0773975>, r_tube <0.506948,-0.0525547,-0.12865>, r_tube <0.624225,0.0127559,-0.133863>, r_tube <0.718547,0.0986739,-0.0935825>, r_tube <0.769215,0.197185,-0.0190641>, r_tube <0.76373,0.295968,0.07055>, r_tube <0.700935,0.381743,0.151708>, r_tube <0.592425,0.444187,0.200665>, r_tube <0.461506,0.480837,0.199122>, r_tube <0.336902,0.502534,0.141567>, r_tube <0.238495,0.534502,0.0434842>, r_tube <0.162369,0.600629,-0.0580741>, r_tube <0.0868258,0.699062,-0.12306>, r_tube <-0.00376094,0.801619,-0.130894>, r_tube <-0.107952,0.874685,-0.0845692>, r_tube <-0.213258,0.8948,-0.00303469>, r_tube <-0.304403,0.853766,0.0868388>, r_tube <-0.369298,0.758796,0.156714>, r_tube <-0.403938,0.630457,0.182717>, r_tube <-0.417153,0.496789,0.15272>, r_tube <-0.431509,0.380148,0.0749723>, r_tube <-0.469611,0.282234,-0.0200497>, r_tube <-0.534325,0.188184,-0.0973564>, r_tube <-0.610828,0.0866908,-0.138519>, r_tube <-0.682597,-0.02296,-0.142462>, r_tube <-0.738272,-0.137241,-0.116252>, r_tube <-0.771226,-0.252727,-0.0690456>, r_tube <-0.77771,-0.366515,-0.00940232>, 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 } }