Airflow control for additive manufacturing

A non-transitory computer readable medium storing a program configured to cause a computer to execute an additive manufacturing process using an additive manufacturing apparatus, the additive manufacturing process comprising:

• forming at least one first solidification line, wherein a gasflow device is positioned in a first orientation such that the flow zone is along a first direction that is substantially perpendicular to the first solidification line and extends substantially parallel to a build platform or a layer of powder disposed thereon;
• and forming at least a second solidification line formed at an angle other than 0° and 180° with respect to the first solidification line, wherein the gasflow device is re-positioned to a second orientation such that the flow zone is substantially perpendicular to the second solidification line,
• wherein the first direction is different from a propagation direction of an irradiation beam from the irradiation beam directing unit;
• and
• wherein during the execution of the additive manufacturing process, the additive manufacturing apparatus build unit is controlled to rotate from the first orientation to the second orientation about an axis substantially perpendicular to the first direction.