A method of 3D printing comprises the steps of running a videogame, in turn comprising a step of generating a virtual game environment comprising in-game geometry; receiving an indication that the current state of the virtual game environment has been selected for 3D printing; obtaining supplementary geometry; and supplementing the in-game geometry with the supplementary geometry to create a 3D printer geometry; wherein components of the virtual game environment included in the 3D printer geometry are modified by the supplementary geometry to have structural features within the 3D printer geometry that have dimensions calculated to support the model in its final printed physical form.