tarptaeya / path_tracer Goto Github PK

require 'parallel'

module PathTracer
  class Scene
    # ...

    def render(ns=1, file="output.ppm")
      puts "writing #{file}"

      # produce a 2d array of all pixels:
      pixels = (0...@height).to_a.product((0...@width).to_a)

      # use all CPU cores for the heavy lifting:
      data = Parallel.map(pixels) do |y,x|
        col = Vector[0, 0, 0]
        (1..ns).each do |s1|
          (1..ns).each do |s2|
            i = (x + (s1 - Random.rand) / ns) / @width.to_f
            j = (y + (s2 - Random.rand) / ns) / @height.to_f
            ray = @camera.ray(i, j)
            col += color(ray)
          end
        end

        percentage = (y * @width + x) * 100 / (@width * @height - 1)
        printf("\r[%-20s] %d%%", "=" * (percentage / 5), percentage)

        col /= (ns * ns).to_f
      end

      # Write the file as before...