Just a few screenshots of a working Polaris made in Phoneburnia mod for Half Life 2: Deathmatch, and a photoshopped Polaris right in the middle there to bring it all together into a cohesive piece.
Keep in mind that it's made using parts available in a game mod for Half Life 2. certain shapes are simply impossible, and there aren't any maps capable of housing a 300-meter-plus ship (nor can I build one, granted that I am limited to 400 spawns).
I build them from parts available through the game's library of entities. The nacelles are made from segments of concrete piping, the secondary hull is made from a water-tower. It's all re-used parts of buildings and props in the game.
Sweet job, man!