Because t_split is less than t_min at this point in our recursive algorithm, this tells us to traverse the right child of C in our tree, which in this case is the leaf node 3. This means that D and its' children are never traversed in our algorithm, which decreases the computation time needed to locate the point at which our ray hits the circle.
Because t_split is less than t_min at this point in our recursive algorithm, this tells us to traverse the right child of C in our tree, which in this case is the leaf node 3. This means that D and its' children are never traversed in our algorithm, which decreases the computation time needed to locate the point at which our ray hits the circle.