Abstract: Disclosed is a method that determines information associated with at least a portion of a build volume that comprises one or more 3D printed objects, and determines an amount of material to be applied to the build volume for use in annealing the one or more 3D printed objects of the build volume, on the basis of the information.

Abstract: Object model data is obtained, representing one or more objects to be generated by an additive manufacturing system. An object model is generated, representing an arrangement of the one or more objects within a build volume, by determining a solution to a packing optimization function. A layer of the object model is analysed to determine a parameter representing the complexity of the layer, and if the determined parameter exceeds a given threshold, the process is repeated by generating a revised object model representing a different arrangement of the one or more objects within the build volume.

Abstract: In an example, a method includes obtaining a compensation model characterising a relationship between a location of an object within a fabrication chamber of an additive manufacturing apparatus and a geometrical compensation to be applied to a model of said object, wherein different geometrical compensation values are associated with different locations. In some examples the method further includes determining a magnitude of a dimension parameter of each object of a set of objects to be generated in a build operation. The method may include determining a spatial arrangement of objects to be generated within the build volume, based on the magnitude of the dimension parameters and the geometrical compensation values for an intended location of object generation in the spatial arrangement.