<p>Geo-mod</p><p>Geo-mod, standing for geographical modification, was mad by Volition, Inc. This engine allows for the player along with any other npcs in the game to cause holes and such in the ground and structures of the game. This game engine was made in 2001 for the games Red Faction and Red Faction 2. This engine would, of course, any future Red Faction games, and any games that would be well suited for making holes in places where they weren’t before, examples of this maybe a miner simulation, or a base building game, possibly even ship and air combat to simulate holes in your vehicle. The strengths of this engine is that no two games are ever the same even in multiplayer, it allows makeshift hideaways to be made, or firing lanes to be opened up. A main weakness of this engine would be that the machine running a game with this engine would have to more powerful than normal to process what it happening and what kind of randomly generated hole in which material and make it so that the player can interact with it without lagging at all.</p><p>Havok</p><p>The Havok engine was made mostly for the use in video games, but has been used in movies, such as X- men movies. This engine allows for real-time collision and dynamics for rigid bodies in 3d and has a highly optimized collision detection library. Games that the Havok engine was used in are the Company of Heroes Series, Uncharted 2: Among Thieves, and Halo 2 and 3. Future games that this can be used in would be pretty much anything that have any large amounts of things flying about and hitting each other, such as steam-punk air bumper cars. </p><p>Source</p><p>The Source Engine developed by Valve, is actually a very heavily modified version of the Havok engine. Quite a few games have been made using the source engine, such as Half-life source, Half-life 2, Team Fortress 2, Portal, Left 4 dead, Left 4 Dead 2 and of course the ever popular sandbox game, Garry’s Mod. The source engine is the perfect engine for games that want to simulate gravity and many items bumping into one another, like the Havok Engine, this allows weapons like the gravity gun to be made, which uses objects that normally would not hurt npcs and players to be propelled and damage things depending on the speed that it is going. The source engine has a facial animation system that allows every character in the game to show emotion depending on what is happening in game.</p><p>Unreal</p><p>The unreal engine was designed with the game designer and artist in mind. The engine makes it so that most anyone can pick it up and with a little training make a level in its editor. The unreal engine allows easy ways to include animations, realistic lighting, particle effects, triggered events and physics into a game. This engine was made by Epic games and included in such titles such as Gears of War, BulletStorm Boarderlands, Batman: Arkham Asylum and you can’t forget the Unreal Tournament Series. This engine may seem like it was made for shooters, but many modders have made several different types of games, such as adventure and plat-forming games. Id Tech </p><p>Id Tech , developed by the game company Id software, which started out in 1990 with the game “Commander Keen and the Invasions of the Vorticons”, is in its fifth rendition of the engine, Id tech 5. This engine started out life known as the “Doom Engine” because it was made for the game “Doom” released in 1993. I think its odd that a company that went from making a fun kids game like Commander Keen then goes on to make Doom, which was every mothers nightmare back in the day. This engine popularized one of the pioneering games of the first person shooter genre. As Id tech evolved it became the Quake 2 engine, Idtech 3 (Quake 3 engine), and Idtech 4 (Doom 3 engine). Idtech 5 features the most advanced version of this family to date, this includes up to 20 GB of texture data, meaning that textures can be in a higher resolution, thus more detailed. This engine also makes use of better lighting and shadows then its previous iterations. The engine will also support multi-threaded processing on the CPU for many of its tasks, including rendering, game logic, AI, physics, and sound processing. It appears that this engine would be user friendly in the ways of level design and such, like unreal, but I have not yet had the chance to try it out.</p>