Sphere, sort of...

sphere.rb

require 'matrix'

class Sphere

  def initialize(shine, shineFocus, mood, r)
    @shades = ['.', ':', '|', '*' 'o', 'e', '&', '%', '#', '@']
    @shine = shine.normalize
    @shineFocus = shineFocus
    @mood = mood
    @r = r
  end

  def strength brightness
    if brightness <= 0
      return @shades.length - 2
    end
    return [0, (1 - brightness) * (@shades.length - 1)].max
  end

  def plotPoint x, y
   print(
    if x**2 + y**2 <= @r**2
      v = Vector[x, y, Math.sqrt(@r**2 - x**2 - y**2)].normalize
      brightness = [0, (-1 * (@shine.dot(v)))].max
      @shades[strength(brightness**@shineFocus + @mood)]
    else
      " "
    end
   )
  end

  def plotLine x
    (((-2**@r).floor)..(2 * @r).ceil).each do |i|
      plotPoint(x, (i / 2 + 0.5))
    end
  end

  def plot
    ((-@r.floor)..(@r.ceil)).each do |i|
      plotLine(i + 0.5)
      puts
    end
  end
end


Sphere.new(
  shine = Vector[30, 30, -60],
  1,
  0.0,
  ARGV[0].to_i
).plot