Welcome: 3DCG M&R

1. Welcome: 3DCG M&R • Modeling • and Rendering • and You

2. Overall Concepts • User (YOU!) • Computer (Lenovo) • Operating system (Win7) • USF Network (Donna/Data) • cs.usfca.edu/~wells

3. Resources • Internet (TCP/IP) • Browser (Netscape, IE) • Online text materials • Siggraph • Tutorials

4. To Model • To build a computer representation of a three-dimensional object or scene • To capture such a representation from the world

5. To Model • To specify a scene by writing a list of statements in a computer graphics Application Programmer’s Interface language (API) or scripting language

6. To Render • To implement a model as an ultimately visual experience • To turn the model into a picture

7. To Render • To process a list of API or script statements into pixels for a generic or specific output device • To create a device-independent display list

8. To Display • To produce an image or other sensible transient or stable artifact • To paint a picture on the screen

9. Modelers • Modelers--built-in • Modelers--stand alone • Free • Inexpensive • Expensive

10. Modeler types • Text-based • Interactive, geometric • Interactive, drawing • Sculptural • Haptic

11. Renderers • Renderers--built-in • Renderers--stand alone • Free • Expensive • Renderers--remote • Renderers--service bureau

12. Renderer types • Vectorizers • Rasterizers • Raytracers • Global illuminators • Scientific visualizers

13. M&R targets • Architectural • Industrial • Character/Entertainment • Graphic Arts

14. Display/output devices • CRT or LCD monitor • Printer • 2D on paper, other media • 3D rapid prototyping • Fabricator • Immersive/haptic systems • File

15. Modeling • The World • Scene • Groups • Objects • Geometry with attributes

16. Modeling details • The Scenegraph = Nodes-with-attributes that are connected

17. Modeling details • Representations • Polygons (wireframe) • Bicubic patches (NURBS) [= NonUniform Rational B-Spline] • Others (later)

18. Modeling details • Coordinate systems • “Framing each object” • Hierarchy sets the scene • A two-way access

19. Introducing Rendering • Wireframe • As solids

20. First rendering details • The view of the scene • Camera parameters • Clipping

21. Rendering examples • From the Pixar Shutterbug sequence ...

22. Let’s start modeling... With sPatch!

24. Representations • Wireframe • Curved Patches • CSG • Procedural models

25. Splines • Parametrized cubic curves • Interpolated points • Control points • 3-D • Patches

26. Model Constructions • Directly draw or lay out • Specify by formula/Math • Specify by word/API • Scan • Capture • Procedural methods

27. Rendering algorithms • Scan line • Raycast vs. Raytrace • Radiosity

28. Rendering styles • Photorealistic • Image-based (Debevec) • Entertainment • Nonphotorealistic (NPR) • Art • Cartoon

31. The Pipeline • Divides the construction of a computer graphics image (CGI) into separate and sequential tasks. • There is no single decomposition

32. The Pipeline • Some of the forces that make different versions: • Different modelers • Different renderers • Different hardware

33. The Pipeline • Common features • Scene building • Coordinatizing the world • Specifying surface “look” • Lighting the scene • Finding what got lit

34. The Pipeline • Distinctive features • Tracing rays • Rasterizing • Adding perspective • Upgrading the lighting

35. A Typical Modeling Pipeline • Objects, possibly in a database or library • Group construction • World construction • Texturing

36. A Typical Ray Tracing Pipeline • Windowing and culling • Ray casting • Shadow casting • Adaptive iteration • Hypersampling

37. A Typical RasterRendering Pipeline • Clipping • Hidden surface removal • Viewing projection • Rasterizing