Question on Book 1 Chapter 6.7 ray_color function

[VxDxK]

Should we unit rec.normal vector in thic code?
hit_record rec; if (world.hit(r, 0, infinity, rec)) { return 0.5 * (rec.normal + color(1,1,1)); }
Or did I make a mistake earlier somewhere in the Hittable code, becaue without this action I`m falling out of color range(from 0 to 1).

[hollasch]

Took me a bit to crawl back through the sample code to figure out what's happening. In code listing The sphere class with normal determination, you can find vec3 outward_normal = (rec.p - center) / radius;. Since rec.p is the hit point on the surface of the sphere, rec.p - center must be a vector of length radius. Thus, dividing by the radius should make this a unit vector. This may be different in your code (you might just have rec.p - center only).

Still, if set_face_normal() expects given vectors to be of unit length, there's nothing really that guarantees or checks that. Further, the color computation above clearly expects rec.normal to be of unit length, so we need to address this.

Spawned issues #1062, #1063.

Thanks for the question.

[VxDxK]

Thanks for the answer