Running Time: 73.170s. (4 bounces, checking bounding box, 4 threads)
Forgot to record the nearest hit point.
Tested with a plane object, forgot to set a bias for the hit point. Besides, didn't use the provided function to get face-normal.
(teapot-low.obj) Bias was too small, at first was 1.0e-5. So I changed it into 1.0e-4.