Media Assets in Computer Games

Text

GraphicsImages – photosAnimationVideoAudioTextCopyright issues

Media Assets used in Games

A graphic can be a vector or bitmap images, such as photographs, sprites, tiling textures, background images, etc

Vector graphics are built up by using shapes. Each shape (object) which makes up a graphic has its own set of properties also known as attributes. A full definition of the attributes of the shape is stored. This is more memory efficient than bit-mapped graphics which store the state of every pixel. Vector graphics have small file sizes in comparison to bit-mapped graphics.

Graphics

Bitmapped graphics are made up of a rectangular grid (or array) of dots or pixels — each of which is stored individually. The colour value of every pixel is stored. File sizes can be large since each pixel would typically take up to three or four bytes. Bitmapped graphics (images) are captured by scanners and digital cameras are bitmapped.

Graphics

File types used in Games include jpeg, bmp, gif

Capture methods: digital camera, scanner Vectors can be drawn with a mouse, keyboard

or graphics tablet

Graphics

A sprite is a figure or character within a game. Sprites usually have a transparent outline and can be animated to simulate movement. Characters in some games are also known as avatars.

A background image is a type of texture that shows a landscape image

3D objects (including characters): Items or characters that can be placed within the game

3D levels: laying out the areas of game play, such as hills, cities, rooms, tunnels, etc, for players and characters to move around in.

What Graphics are used for

Skyboxes: a skybox is a cube with background images that surrounds the game player in a 3D game.

What Graphics are used for

Textures: textures are attributes of graphics. This attribute defines the surface appearance of what objects with look like. It can be thought of as the skin of that wraps around the 3D framework of the object to give it a more realistic appearance images that are mapped onto surfaces of objects such as stone walls and wooden tables.

What Graphics are used for

A video is a moving image file in a format that is compatible with the game development environment

file types — avi, mpeg wav methods of capture — digital video camera Adobe Premier and Song Vegas are used to

edit videotools for editing — titling, cropping

Videos

An animation is a collection of still images with each one in the sequence slightly different from the previous. The images are played quickly one after the other to give the illusion of movement. This is known as the frame rate.

Animation

2D (dimension) is used to create cartoon style games

Software such as Adobe Flash is used to create online games.

File format – gif and swf

Animation

3D is used to create realistic, life like games3D Studio Max and Maya are just some of the

software used to create 3D animation

Animation

FPS (Frames per Second) is the frame rate for playing back animation and video. 12fps is the minimum acceptable rate15fps is common for the web24 fps for film25fps for PAL (British TV)30fps for NTSC (USA TV)

Image resolution determines how many dots per inch as used for images e.g. 72 dpi, 96 dpi are the most common

Screen resolution determines how may pixels (width x height) make up a screen e.g. 800 x 600, 1024 x 756, 1280 x 1024. Control Panel>Display. TVs tend to have smaller resolutions than computer screens, so pictures on a computer may not look as pixelated.

Colour depth is the amount of colours per pixel e.g 16, 24, 32, 48 – change this under Control Panel>Display.

The bigger the number = bigger file size

Properties of Media Assets

Audio is sound of any type played in a game. Types of audio media assets include:

Speech: such as the voices for characters Sound effects: noises of objects in the game. Music: background music that usually loops

and repeats during the game play. Software – Adobe Audition, Audacityfile types — raw, wav, mp3, midi. methods of capture — from microphone,

extract from CD, using audio keyboard tools for editing — echo, change pitch, speed,

amplify change tempo

Audio

Text media assets are required for the game to provide dialogue, create and atmosphere give player feedback or instructions

file types — txt, rtf methods of capture — keyboard, scanner,

voice recognition, handwriting recognition Software used – Microsoft Word, Notepad,

Word pad

Text

You need to get copyright permission to use ready made assets and you may have to pay royalties to use them.

Games companies in the UK are protected by the Copyright Designs and Patents act http://www.copyrightservice.co.uk/copyright/p01_uk_copyright_law

Royalty free assets mean that you pay once and have to adhere to the terms and conditions.

Creative Commons assets mean that you can use them for free if you adhere to the terms and conditions http://search.creativecommons.org

Copyright

Media assets can take up a lot of storage space and memory, especially video and 3D animation.

When you save or export these files you normally have to save then as a compressed file format such as: Mp3 (audio), mpeg 1/2/4 (video) GIF (graphics) Jpeg (photos, life like graphics, graphics with effects) Swf (2D animation)

Compression looks for repeat information in a file and reduces it in some way.

The aim is to keep the quality of the file but reduce the file size of it.

There are 2 types: Lossy (jpeg, mpeg) gets rid of data permanently. Don’t keep

editing this Lossless (gif) temporarily gets rid of some data until the file is

opened (decompressed). File sizes are usually not as small as lossy.

File Compression