1. A computer implemented method of processing mesh data defining the spatial co-ordinates in a co-ordinate space of vertices of a mesh surface and texture co-ordinate data associating vertices of a mesh surface with locations in an image space of an image to be rendered onto the mesh surface, the method comprising: using a computer to determine for each of the vertices of a mesh surface represented by mesh data, spatial error vectors identifying the differences in between spatial co-ordinates of vertices of the mesh surface as defined by the mesh data and the spatial co-ordinates of corresponding vertices in a mesh surface generated from an encoded representation of the mesh data; determine a mapping projection between the co-ordinate space of the mesh data and the image space of an image to be rendered onto the mesh surface; and modify texture co-ordinate data to associate vertices of the mesh with locations in image space which differ from the locations identified by the unmodified texture co-ordinate data by amounts corresponding to a projection of the determined spatial error vector associated with a vertex to the image space in accordance with the determined mapping.