To summarize, find t for the ray where it meets with the circle and check if the z is within (-L/2, L/2). And also check the intersection point of the ray and the plane of either the top circle or the bottom circle and see if the intersection point is within the circle.
To summarize, find t for the ray where it meets with the circle and check if the z is within (-L/2, L/2). And also check the intersection point of the ray and the plane of either the top circle or the bottom circle and see if the intersection point is within the circle.