Jan VarhoPython Raytracer in 50 Lines of Code
I've come to like the expressiveness of the Python language, though I dislike some of the other features. Here's a 50 line raytracer that renders scenes of colored spheres to a PNG file:
import math from PIL import Image
def sub(v1, v2): return [x-y for x,y in zip(v1, v2)] def dot(v1, v2): return sum([x*y for x,y in zip(v1, v2)]) def norm(v): return [x/math.sqrt(dot(v,v)) for x in v]
def trace_sphere(r, s, tmin, color): sr = sub(s[0], r[0]) dsr = dot(sr, r[1])
d = dsr*dsr - dot(sr,sr) + s[1] if d < 0: return d = math.sqrt(d)
t1 = dsr + d if t1 < 0: return
t2 = dsr - d if t2 > tmin[0]: return
if t2 < 0: tmin[0] = t1 else: tmin[0] = t2 color[:] = [s[2]]
def trace_ray(ray, spheres): color = [(0, 0, 0)] tmin = [100000] for s in spheres: trace_sphere(ray, s, tmin, color) return color[0]
red = (255,0,0) blue = (0,0,255) spheres = ( ((0,0,100), 100.0, red), ((0,-5,50), 20.0, blue) )
w, h = 200, 200
image = Image.new("RGB", (w, h)) pix = image.load()
for x in range(w): for y in range(h): ray = ( (0,0,0), norm(((x-w/2.0)/w, (y-h/2.0)/w, 1)) ) pix[x,y] = trace_ray(ray, spheres)
image.save("out.png")
Ok, it's more like 30 significant likes to tell the truth.