1. A computer-implemented method for generating a representation of a mesostructure for use in rendering a synthesized image, the method comprising: determining a value for each voxel within a volumetric texture of the mesostructure, the value being based on a location of the voxel relative to the mesostructure within the volumetric texture and being based on a computed distance of the voxel in relation to a boundary of the mesostructure calculated over a plurality of view directions for the voxel.