Book 3: Cosine calculated incorrectly

[spkersten]

Here it seems the wrong vector is normalised:

raytracing.github.io/books/RayTracingTheRestOfYourLife.html

Lines 1556 to 1558 in 62ce2e6

	scattered = ray(rec.p, unit_vector(scatter_direction), r_in.time());
	alb = albedo->value(rec.u, rec.v, rec.p);
	pdf = dot(rec.normal, scattered.direction()) / pi;

In creating a ray, scatter_direction is normalised while ray.direction (by convention) doesn't need to be normalised, while in calculating the cosine for the PDF value, scatter_direction is not normalised but it should.

[spkersten]

Never mind. All is fine, since scattered.direction() is unit_vector(scatter_direction).