hello.i have started to play around again with the lovely superformula shaders from sanch.

on bourke´s website http://local.wasp.uwa.edu.au/~pbourke/geometry/supershape3d/ i ran into the possibility of creating shells with the superformula.

i do not understand the particular case clearly, where he states…

The supershape function can obviously be modulated by another function. For example to create the shell like structures below, the radius (r1) of the superformula that varies the longitude is scaled by either a logarithmic or Archimedes spiral. In some cases the z coordinate is additionally made a linear function of longitude.

does this mean, that i have to replace in the shader code r1 with the formula for an Archimedes spiral?

x(t) = R cos(t), y(t) = R sin(t)

r(t) = at (a is constant)

or just using the values generated by the formula above. however, sofar i could not make it work.

neither in the superformula3d nor superformula2d3d shaders.

help very appreciated. thanx to sanch for the shaders!

my warm regards,

dd