1. The Purpose of game Engines
In this presentation I will discuss what types of game engines we use, why we use them and the functionality of the software.

2. What are game engines?
While we know that a game engine is what computer software developers use to assist the composing of a video game, they usually fall under four categories 2D (Game Salad), 3D (Unreal Engine), Mobile (Battery Tech) and Game Mods (Garrys Mod). One of the main features of a game engine is to be able to render 2D or 3D images in real time, the engine is also responsible for such things as Physics, Artificial Intelligence, collisions and particle effects.

3. Current game engines.
The Source Engine is a 3D game engine developed by Valve Corporation.
The engine focuses on making a game look incredible and is very artist- driven. This includes a shader-based renderer (including a shader library) accurate lip sync and facial expression technology, and a powerful physics system.
The software also includes a full range of special effects. Including particles, beams, volumetric smoke, sparks, blood and environmental effects like fog and rain, as well as particle effects. Source’s advanced particle system can emit sprites or models for realistic fire, explosions, snow, and more.

4. Another type of game engine is Unity:
Unity is a cross-platform game engine developed by Unity Technologies
Unity game engine is slightly less complicated than Source due to its simpler interface. It is cross-platform integration, meaning games can be quickly and easily imported onto Android, iOS, Windows Phone 8, and BlackBerry, making it a great game engine for the development of mobile games, however it also has the capabilities of development for consoles.
The game engine supports assets from major 3D applications like Maya, CINEMA 4D, Blender and more, meaning there is no real restrictions to the type of file formats that it supports.

5. What is the purpose of game engines?
Some people define game engines similar to car engines. You can take the engine out of the car, and build another shell around it, and use it again. The engine is what powers the game. Graphic rendering is the process of generating an image from a model through using the games engine. What this basically means in that the engine is taking a 3D object and showing it to us in the form of a 2D image.
Collision detection is an essential part in 3D games. It ensures that the game physics are relatively realistic, so that an object does not cut through other objects or hovers when it should fall. Generally you will have a simple generic shape that covers the invisible block known as a "hitbox" so even though collision may not be pixel perfect, it will look good and perform well to the player.

6. - developer.valvesoftware.com
Artificial intelligence is used to give character dimension to NPC's as a way to immerse the player into the story of the game.
Every AI has a set of basic requirements. Modern video games feature sophisticated and realistic environments, therefore the need for smart and comprehensive agents is important. Since video game AI is often specifically designed for each game, video game AI tools currently focus on allowing game developers to quickly and efficiently create specific AI to suit their setting. This is why game engines are helpful, as source has developed a:
sophisticated AI system allows NPCs to follow players, join in the fight, or engage the player in epic non-scripted battles. AI characters can run, fly, jump, crouch, climb stairs, and burrow underground.
- developer.valvesoftware.com

7. Most game engines provide facilities that ease development, such as graphics, sound, physics and AI functions. One of the components of a game engine is the audio engine. The audio engine is the part of the software which consists of any algorithms related to sound. The use of this software eases the development of games for creators. Similarly, the physics engine is part of the software that provides an approximate simulation of physical items.This includes rigid body dynamics (including collision detection) which makes objects look as if they are moving like they would in real life.

8. In the broader sense of the term, game engines themselves can be described as middleware. In the context of video games, however, the term "middleware" is often used to refer to the components within a game engine. Some game middleware only does one thing but does it more efficiently than general purpose middleware. For example, SpeedTree was used to render the realistic trees and vegetation in The Elder Scrolls IV: Oblivion

9. Thank you :)