Digital Camera Analogy ● How do we take a picture of a person indoor? ● A target (object) needs to be determined. → geometry ● The person needs to wear proper clothes. → material ● The object needs to be moved & posed properly. → transformation ● We need to set lighting properly. → lighting ● We need to choose a proper lens. → projection ● We need a proper setting of the camera. → advanced techniques ● The camera needs to be moved to a proper position & angle. → transformation & projection

Rendering “...process of generating an image from a model (or models in what collectively could be called a scene file), by means of computer programs.” (Wikipedia)Wikipedia ● What is a “scene”? “A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene.” (Wikipedia)

Rendering (cont'd) ● How does it work in real world? How does a digital camera work? ● “How can a human perceive an image?” : Human vision systems→HVS model developedHuman vision systemsHVS model ● “How does light behave?” : Optics→Rendering equationOpticsRendering equation ● Why don't we just simulate what actually happens? → It's tooooooo complicated!

Rendering Algorithms ● Four families Four families ● Ray casting Ray casting – Image order algorithm – Simpler than ray tracing – Wolfenstein 3D Wolfenstein 3D ● Ray tracing Ray tracing – Photorealistic ● Radiosity Radiosity – Captures 'ambience' – Viewpoint independent ● Scanline rendering & rasterization – Which pixels does each primitive occupy? → Object order algorithm – Graphics pipeline Graphics pipeline – OpenGL, DirectX, etc. → Usually combines two or more techniques

3D Graphics Libraries ● List of 3D graphics libraries (Wikipedia) List of 3D graphics libraries ● Low level – fast, hard to use – OpenGL OpenGL – Direct3D Direct3D ● High level – slow, easy to use – Java 3D Java 3D – OpenSceneGraph OpenSceneGraph