3D Game Programming All in One By Kenneth C. Finney

Chapter 8 Introduction to Textures

Introduction to Textures Textures establish look and feel Texture mapping is the process that applies textures to shapes Textures create appearance of sub-structure and detail Textures can reduce need for complex (high poly count) shapes Textures can be animated to give sense of motion

Introduction to Textures Textures are well suited for depicting high-tech devices Textures can have transparent or translucent sections Textures can be derived from artwork or photographs Textures are well suited for supplying subtle hints and cues

Introduction to Textures Paint Shop Pro: image manipulation creating original art supports all popular formats and many obscure formats includes built-in scanner and digital camera support as well as image analysis tools

Introduction to Textures Lab 1: Creating a texture –learn some simple PSP 8 operations –learn how PSP provides built-in texture creation capabilities –discover how different properties can affect a texture's appearance –Practice saving textures

Introduction to Textures Portable Network Graphics (PNG) files very efficient compression supports one alpha (transparency) layer in addition to image layer fairly new file format—support by imaging tools is very high, but not yet 100%

Introduction to Textures Joint Photographic Experts Group (JPEG) files widely available format very efficient compression lossy compression (some data is discarded when image is compressed) too much data loss can lead to compression artifacts in a JPEG image no layer support

Introduction to Textures Lab 2: PNG vs. JPG –learn how to add noise to an image –save a single image in different formats –use the Recent Files command –use the Zoom Tool –discover JPG compression artifacts –compare JPG and PNG versions of the same image

Introduction to Textures Bitmap versus Vector Images –bitmaps in PSP are called raster images, an older expression –bitmaps are pixels laid out on a grid –bitmap pixel values determine color in red, green, and blue (rgb) tuples –bitmaps are resolution-dependent

Introduction to Textures Bitmap versus Vector Images –vector images use procedural instructions for drawing an image –vector images have objects that are stored as drawing instructions –vector images are not dependant on resolution

Introduction to Textures Creating Alpha Channels –alpha channels describe transparent parts of an image –Used for GUI overlays and objects with empty parts –Alpha channel info saved with image in PNG formatted files –Alpha channels also describe translucency

Introduction to Textures Lab 3: Alpha Channel –learn the freehand selection tool –learn how alpha channel info is handled in PSP –witness results as displayed by Torque engine

Introduction to Textures PSP Features –materials –layers –tool options –paint brush –air brush –clone brush –eraser

Introduction to Textures PSP Features –Selection –Masks –Scaling –Rotating –Image sizing –Text

Summary Textures: –create and sustain the look and feel, or ambience, of a game –impart apparent properties to a 3D object –create the illusion of substructure and detail on 3D objects Textures are used in terrains, skies, clouds, storms, characters, weapons, vehicles, and many other 3D objects

Summary Paint Shop Pro—image processing tool—any similar tool can be used JPG (or JPEG)—no layer support, lossy compression, very common PNG—alpha transparency layer, non- lossy compression A vector image—series of procedural and mathematical instructions A bitmap image—an array of stored data specifying color and intensity of pixels