Abstract: In an example, a method comprises receiving, at a processor, a digital model representing an object to be produced by additive manufacturing. The method may comprise receiving, at the processor, an indication that a first selected region of a surface of the object is to have a first coating applied after printing. The method may further comprise applying a first predefined surface roughness pattern to the first selected region of the surface of the digital model.

Abstract: An example method includes obtaining a geometric compensation profile characterising a relationship between a location of an object within a first fabrication volume having a first depth of build material and a geometrical compensation to be applied to a model of said object. The method further includes determining that a first object is to be generated in a first build operation having a second fabrication volume which has a second depth. The method may further include determining a geometrical compensation to be applied to a model of the first object by: determining a first offset of the first object from the top of the second fabrication volume; identifying the geometrical compensation value associated with a location having the first offset from the top of the first fabrication volume; and determining the compensation to be applied to the model of the first object based on the identified geometrical compensation value.

Abstract: Methods of treating fused build material in an additive manufacturing system are described. The method includes a first treatment process comprising: depositing unfused build material over the fused build material in a working area of the additive manufacturing system, thereby providing a first build material layer; and supplying energy from a first energy source to the first build material layer to heat but substantially not fuse the unfused build material of the first build material layer. The method also includes a second treatment process comprising: depositing unfused build material over the first build material layer in the working area, thereby providing a second build material layer; and supplying energy from a second energy source to the second build material layer to heat but substantially not fuse the unfused build material of the first and second build material layers.

Abstract: A mobile build unit (2) for selectively locating in a build chamber (4) of an additive manufacturing machine (6). The mobile build unit has a build platform (8) to receive build material; and a build unit heater (10) to heat layers of build volume formed on the build platform (8). The build unit heater (10) is movable between a first position in which the build unit heater (10) is stored, and a second position in which the build unit heater (10) is mounted over the build platform (8).