In an example, a method includes analysing, using at least one processor, object model data representing at least a portion of an object to be generated by an additive manufacturing apparatus by fusing a build material to determine at least one predicted object generation temperature. The method may further include identifying, using at least one processor and from said analysing, a feature of the at least a portion of the object associated with a predicted object generation temperature which is below a fusing temperature of build material to be used in object generation. The method may further include determining, using at least one processor, modification data to be used in object generation, the modification data being to increase a temperature of the feature in object generation.