Multimedia

1. Multimedia Week 20 Lighting

2. Last week • Animation • Cameras • Video • Streaming • Compression • Production Multimedia

3. This week • Realtime and photorealistic • Rendering • Lighting concepts • Types of lighting • Shadows Multimedia

4. Realtime v. photorealistic • Compare lighting • OpenGL - max 8 • Photorealistic – 10 per character • Convergence of realtime and photorealistic • Realtime is now used to plan real movies • Used extensively in games Multimedia

5. The CG production pipeline Traditional Story Editorial Art Internal or 3rd party Modelling Set design Layout Animation Shading Lighting Simulation Effects Commercial Rendering Film Multimedia

6. Rendering • The act of translating the information in the files that make up the shot into a single frame of film • Rendering "fills in" geometry with color, shadow, lighting effects, etc. • Pixar have created Renderman • 10 years ago it took 6 hours to render one frame • How many today? • Use render farms Multimedia

7. Concepts • Light has warmth (yellowish) or coolness (bluish) • Intensity • Angle if incidence • Radiosity • Light reflecting from an object • Attenuation • Light becomes weaker with distance 3ds max v7 Multimedia

8. Lighting basics • Three main sources of lighting in classic photography • Key • Fill • Backlight • Concepts apply to 3D programs, plus • Ambient light Multimedia

9. Getting it right 3ds max v7 Multimedia

10. Key light • Outdoors • The sun • Indoors • Major window • Main electric light • Flash on a camera • Spot light on a stage Multimedia

11. Fill and key lights • Fills in the dark shadows cast by the key light • Outdoors may be created artificially • Indoors from secondary lights • Distant window • Light fitting • Softens shadows 3ds max v7 Multimedia

12. Backlight • Situated behind the subject • Separates the foreground from the background • Can make the scene more three-dimensional Multimedia

13. Lighting strategies 3ds max v7 Multimedia

14. Planning lighting • Default lighting • Use this until you are happy with the scene, then add lights • Use as few as possible • Start with the key light • Maybe a spot • Add fill • Use omni or several spots • Finally add accent lighting 3ds max v7 Multimedia

15. Ambient light • Not a light source • Light from other sources bouncing of walls, the ceiling and other objects in the scene 3ds max v7 Multimedia

16. Types of lighting • Standard • Spotlights • Omnidirectional light • Directional light • Advanced • Photometric lights Multimedia

17. Spotlights • Casts a focused beam of light like a flashlight, a follow spot in a theatre, or a car headlight 3ds max v7 Multimedia

18. Omnidirectional light • Known as omni light • Like a bare light bulb • Casts rays in all directions from a single source 3ds max v7 Multimedia

19. Directional light • Also known as Distant lights • Cast parallel light rays • Primarily used to simulate sunlight Multimedia

20. Target lights • Concept like cameras • Target • Easier to aim • Simply position the target object at the centre of interest • Free 3ds max v7 Multimedia

21. Lighting direction Single light from side Single light straight on Both sides Reduced full fill 3ds max v7 Multimedia

22. Activity • Open up your model of a room, save with a new file namse • Add one or more spotlights to provide lighting and render the scene • Experiment with moving them around and rendering the effect • Add an omni light behind the scene • Alter the values to achieve a balanced rendering Multimedia

23. Standard light settings • Intensity • Angle of incidence • Attenuation • Reflected light and ambient light • Colour Multimedia

24. Attenuation • Natural reduction of light intensity 3ds max v7 Multimedia

25. Brightness and colour • Intensity sets the brightness of the scene • Range from 0 to 255 (white) • Colour – use the RGB sliders 3ds max v7 Multimedia

26. Activity • With your scene experiment with your light settings • Vary the light settings for: • Intensity • Angle of incidence • Attenuation • Reflected light and ambient light • Colour Multimedia

27. Use of shadows Default lighting Spot 3ds max v7 Spot plus low level back lighting Multimedia

28. Shadows • Photometric and standard lights both have the same options for generating shadows • Two types • Shadow mapped • Ray-traced Multimedia

29. Shadow mapped • Grayscaled texture map based on the lighting and mesh • Soft-edged • More natural • May be blocky • May be inaccurate • May be incorrectly positioned • Do not take transparency into account • Do not take on the colour cast of the object • May use a lot of RAM 3ds max v7 Multimedia

30. Ray traced shadows • Ray tracing techniques • Have a hard edge • Software can be used to soften • Very accurate and precise • Does not use a lot of RAM 3ds max v7 Multimedia

31. Hotspot and falloff • Hotspot • Angle of the inner portion of the beam • Falloff • Angle of the outer beam • Differences in angles make the effect softer 3ds max v7 Multimedia

32. Include and exclude • Some software allows you to set up lights that affect only certain objects • Use a pick list to select objects Multimedia

33. Colour and mood • Cool colours – blues and violets • Still and calm • Warm colours – yellows, red and orange • Fiery and energetic • Intense and active • Be careful, keep it subtle Multimedia

34. Activity • Create a flat surface with a sphere and a cone sitting on top • Add a spot light • Add a fill light • Alter the hotspot/fallout • Alter the type of shadow Multimedia

35. Photometric lights • Photometric lights enable you to more accurately define lights as they would be in the real world using ray tracing • Distribution, intensity, colour temperature can be set 3ds max v7 Multimedia

36. Global Illumination with Radiosity • Standard lights are simpler than natural lighting • Using photometric lights with a radiosity solution with your lights provides a better model of the real world • Radiosity is rendering technology that realistically simulates the way in which light interacts in an environment Multimedia

37. Preset photometric lights • Generic 60W Bulb • Generic 75W Bulb • Generic 100W Bulb • Generic Halogen Spotlight • Generic Recessed 75W Lamp (web) • Generic Recessed 75W Wallwash (web) • Generic Recessed 250W Wallwash (web) • Generic 4ft Pendant Fluorescent (web) • Generic 4ft Cove Fluorescent (web) • Generic Street 400W Lamp (web) • Generic Stadium 100W Lamp (web) Multimedia

38. Photometric lights • Target Point • Similar to a standard omni light, emits light from a geometric point • Spotlight • Focused beam • Web distribution • Distribution of light • Many lighting manufacturers provide web files that model their products 3ds max v7 Multimedia

39. Sunlight and Daylight • A system that follows the geographically correct angle and movement of the sun over the earth at a given location • You can choose • Location • Date and time • Compass orientation. 3ds max v7 Multimedia

40. Daylight • Daylight combines sunlight and skylight • The sunlight component can be either • IES Sun light • Illuminating Engineering Society • Values set automatically based on geographic location, time, and date • Or a standard light (a target direct light). • The sky component can be either an • IES Sky light • Or a Skylight. Multimedia

41. Self assessment • You have been asked to model a lecture theatre for Hope • Compare and contrast the lighting required for • A guest lecture without note taking • A lecture with note taking and discussion sessions Multimedia

42. For Next Week • Submit your Portfolio 2.2 • Work on the 3ds max tutorials • Directed reading chapter 6 and 10 • Giambruno M, (2002) 3D Graphics & Animation, 2nd Edition Multimedia

43. References • Giambruno M, (2002) 3D Graphics & Animation, 2nd Edition, New Riders, ISBN: 0-7357-1243-3 • Kerlow I. V., (2003) The Art of 3-D Computer Animation and Effects , 3rd Edition, John Wiley & Sons Inc; ISBN: 0471430366 • Murdock K.L., (2005) 3DS Max 7 Bible, John Wiley & Sons Inc, ISBN: 0764579711 • Screen shots taken from 3ds max 7 User Reference Multimedia