An additive manufacturing apparatus includes a platform, a dispenser configured to deliver a plurality of successive layers of feed material onto the platform, at least one light source configured to generate a first light beam and a second light beam, a polygon mirror scanner, an actuator, and a galvo mirror scanner. The polygon mirror scanner is configured to receive the first light beam and reflect the first light beam towards the platform. Rotation of the first polygon mirror causes the light beam to move in a first direction along a path on a layer of feed material on the platform. The actuator is configured to cause the path to move along a second direction at a non-zero angle relative to the first direction. The galvo mirror scanner system is configured to receive the second light beam and reflect the second light beam toward the platform.