message: use safe reciprocal in intersectBox().
diff: @@ -109,8 +109,8 @@ inline void intersectBox(const Ray& ray,
  float& t0,
  float& t1)
  {
  - const vec3f mins = (box.lower - ray.org) * rcp(ray.dir);
  - const vec3f maxs = (box.upper - ray.org) * rcp(ray.dir);
  + const vec3f mins = (box.lower - ray.org) * rcp_safe(ray.dir);
  + const vec3f maxs = (box.upper - ray.org) * rcp_safe(ray.dir);
  t0 = reduce_max(make_vec4f(min(mins, maxs), ray.t0));
  t1 = reduce_min(make_vec4f(max(mins, maxs), ray.t));
  }
  