1. Graphics Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting, Fogging, Alpha Blending & Progressive Meshes Byeong-Seon Jeong 2002.1.22

2. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Contents Lighting Fogging Alpha Blending Progressive Meshes Demo

3. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting Ambient Light is effectively everywhere in a scene a general level of light that fills an entire scene has no position or direction, only color and intensity Direct Light Point  give off light equally in all directions  have color and position within a scene, but no single direction

4. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(directional) Directional  emit parallel light  have only color and direction, not position  a light source at near infinite distance, such as the sun

5. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(spot) Spot  is made up of a bright inner cone and a larger outer cone  have color, position, and direction in which they emit light

6. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(global illumination) Global Illumination Formula

7. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(ambient) Lighting Model Ambient  provides constant lighting for a scene  lights all object vertices the same  Formula

8. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(ambient)  Scene

9. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(ambient) Source Code

10. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(diffuse) Diffuse  comes from one direction  is scattered equally in all directions once it hits a surface  Formula

11. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(diffuse)  Attenuation Factor

12. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(diffuse)  Spotlight Factor

13. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(diffuse)  Scene

14. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(diffuse)  Source Code

15. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(specular) Specular  comes from a particular direction  tends to bounce off the surface in a preferred direction  Shiny metal, plastic  Formula

16. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(specular)  Scene

17. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(specular)  Source Code

18. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(emissive) Emissive  is emitted by an object  Glow  Formula

19. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(emissive)  Scene

20. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Lighting(emissive)  Source Code

21. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging Adding fog to a 3-D scene can enhance realism provide ambiance or set a mood, and obscure artifacts Formula

22. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(factors) Factors  Linear

23. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(factors)  Exp

24. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(factors)  Exp2

25. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(graph) The Illumination graph of the formula

26. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(scene) Scene

27. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Fogging(source code) Source code

28. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Alpha Blending combines the color value of the processed polygon pixel with the pixel already stored in the frame buffer Formula

29. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Alpha Blending(scene) Scene

30. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Alpha Blending(source code) Source Code

31. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Progressive Meshes A progressive mesh is one in which the vertex information is stored internally in a special tree that can be accessed to render the mesh with any number of vertices. This procedure is fast, so progressive meshes are ideal for level-of-detail scenarios, where objects in the distance are rendered with fewer polygons.

32. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Progressive Meshes(diagram) Progressive Mesh Flow Diagram Graphic files Ex. *.3DS, *.ASE etc Dynamic LOD User input Ex: Distance *.X file load Material & Texture setup Progressive Mesh creation Progressive Mesh Level Control Rendering Initialization Update frame

33. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Progressive Meshes(scene) Scene

34. CGVR Graphics Lab @ Korea University cgvr.korea.ac.kr Demo