Rendering of an isosurface inspired by a work by Escher, Sphere Spirals.
Formulas for Povray from “Almost Sphere Spirals” by Tor Olav Kristensen (2002)
‘Tor Olav Kristensen’ said
An isosurface shape inspired by M.C. Escher’s “Sphere Spirals” (“Bolspiralen”) woodcut print from 1958. The edges of the four spiraling bands on the sphere can be formed by an inverse stereographic projection of eight infinite logarithmic spirals in a complex plane tangent to a Riemann Sphere onto it’s surface. I found some useful information about this shape here.
Shot 1: Twisting rate at 1.5, 4 bands. 1920 x 1080. Rendering: about 2 hours.
Shot 2: Twisting rate at 0.1, 1 band. 1920 x 1080. Rendering: about 20 hours.
Shot 3: Twisting rate at 0.5, 4 bands. 1920 x 1080. Rendering: about 8 hours.
Shot 4: Twisting rate at 1.9, 12 bands. 1920 x 1080. Rendering: about 1 hour.
Shot 5: Twisting rate at 1.0, 4 bands, fog. 1920 x 1080. Rendering: about 8 hours.
Animation: Variable twisting rate from 1 to 3, 4 bands. 640 x 360, 30 fps, 600 frames (20 sec). Rendering: about 2–3 weeks on 3 machines, with time ranging from 3 hours to half an hour per frame.
All with default antialiasing, without radiosity.
In detail, reflections do not particularly affect rendering times. It’s the isosurface that “kills” performance, especially with low twisting rate values.