Creating High-Quality Maps in Source

Many recent high-quality Source maps (e.g. Black Mesa's Black Mesa (Source)/Xen levels and Cascade (de_prime)) have very complex and intricate geometry across the entire level. While Hammer can create similar geometry seen in the Antlion Caves in Half-Life 2: Episode Two, Displacements can only accomplish so much before reaching their limitations. The answer to how these maps are created is simple: Models. Created using superior third party modeling programs (e.g. Blender), small parts of levels are modeled and then combined in Hammer to create a very high-quality and detailed map.