The city was broken up into a number of economic areas with appropriate architecture. So newer complete structures and the few well preserved Roman buildings would be in the nice area while in the worst off area there would be completely ruined structures and a lot of appropriated ruins for simple stucco and thatched hut homes and markets.
The story itself took place on a lower class market street. Since there's some new money in a lower class area there's was a wider diversity of building types. And because the film took place on this street there was the most attention to detail for those buildings.
There were a number of repeating material textures I created for use throughout the city. I thought of the textures in terms of materials such as good stone, unkempt stone, and destitute stone. These textures would then be layered using alpha channels and in some cases multiple uv maps to create the final look of the film. Due to the production schedule I didn't then take the step of baking the textures to a single UV map and texture image