def Lighting(material, obj, light, point, eyev, normalv, inShadow=None):
color = Color()
if material.pattern != None:
color = pattern_at_object(material.pattern, obj, point)
else:
color = material.color
effective_color = Color.multiply(color, light.intensity)
lightv = Vector3.Normalize(Tuples.sub(light.position, point))
ambient = Color.multiply(effective_color, material.ambient)
light_dot_normal = Tuples.dot(lightv, normalv)
if light_dot_normal < 0 or inShadow == True:
diffuse = Color()
specular = Color()
else:
diffuse = Color.multiply(effective_color,
material.diffuse * light_dot_normal)
reflectv = Tuples.reflect(Tuples.NegateTuple(lightv), normalv)
reflect_dot_eye = Tuples.dot(reflectv, eyev)
if reflect_dot_eye <= 0:
specular = Color()
else:
factor = pow(reflect_dot_eye, material.shininess)
specular = Color.multiply(light.intensity,
material.specular * factor)
return Color.add(Color.add(ambient, diffuse), specular)
