--- a/demos/spheres_shadow.py	Mon Nov 26 17:31:37 2007 +0100
+++ b/demos/spheres_shadow.py	Mon Nov 26 23:12:40 2007 +0100
@@ -8,10 +8,10 @@
 
 rt = Raytracer()
 
-light1 = Light(position=(0.0, 5.0, 5.0), colour=(0.7, 0.3, 0.6))
+light1 = Light(position=(0.0, 5.0, -5.0), colour=(0.7, 0.3, 0.6))
 rt.addlight(light1)
 
-light2 = Light(position=(-2.0, 10.0, 2.0), colour=(0.4, 0.6, 0.3))
+light2 = Light(position=(-2.0, 10.0, -2.0), colour=(0.4, 0.6, 0.3))
 rt.addlight(light2)
 
 mat0 = Material(colour=(0.7, 0.7, 0.7))
@@ -20,15 +20,15 @@
 rt.addshape(box)
 
 mat1 = Material(colour=(1.0, 0.0, 0.0))
-bigsphere = Sphere(centre=(3.0, 2.0, 7.0), radius=3.0, material=mat1)
+bigsphere = Sphere(centre=(3.0, 2.0, -7.0), radius=3.0, material=mat1)
 rt.addshape(bigsphere)
 
 mat2 = Material(colour=(0.0, 1.0, 0.0))
-smallsphere = Sphere(centre=(-5.5, 1.5, 8.0), radius=2.0, material=mat2)
+smallsphere = Sphere(centre=(-5.5, 1.5, -8.0), radius=2.0, material=mat2)
 rt.addshape(smallsphere)
 
 mat3 = Material(colour=(0.0, 0.0, 1.0))
-tinysphere = Sphere(centre=(-1.2, 0.0, 2.0), radius=0.5, material=mat3)
+tinysphere = Sphere(centre=(-1.2, 0.0, -2.0), radius=0.5, material=mat3)
 rt.addshape(tinysphere)
 
 imagesize = (800, 600)