Abstract: Additive manufacturing promises new pathways for integration of advanced alloys with complex structural component design for aerospace applications. Achieving desired properties mandates control of structure and an improved understanding of the processes that occur at the individual melt pool scale and their superposition as melting occurs on a layer- by-layer basis. The data challenges with additive manufacturing and the corresponding 3D quantification of structure will be addressed. New insights on structure development gained from 3D datasets with chemical, structural and misorientation information will be discussed for structural alloys printed by electron beam and laser powder based processes. In large 3D datasets, the persistence of grains and the accumulation of large crystallographic misorientations during printing been studied as a function of scan strategy. The benefits of multimodal data for characterization of submicron features will be discussed. Finally, challenges in the design of alloys that are tailored to these unique processing paths will be discussed.