1. A Very Brief Overview of Non-Photorealistic Rendering Conrad Albrecht-Buehler Graduate Thesis Seminar September 24, 2001

2. What is Non-Photorealistic Rendering (NPR)? Rendering of an image to mimic media other than a photograph Gooch: provide info not readily apparent in a photo

3. NPR’s Usefulness New Artistic Tools Can provide more useful information than a photo might Lends attractiveness to visualizations New modes of visualization

4. NPR Applications Artist Tool Architecture Cinema Games Scientific Visualization Cartography

5. Types of NPR Image Space Effects Perspective Space Effects Data Mapped Visualization

6. Image Space Effects Techniques applied to an output image Style “filters” mimic a familiar artistic style by modifying the pixel image Some work has been done in automatic media generation based on an imput image, e.g. watercolor

7. From Teece

9. From Curtis et al.

10. Perspective Space Effects Techniques applied on input models Much work has been done recreating artistic styles using 3D models as subjects Toon Shaders typically highlight silhouettes based on the model Technical and Architectural sketch renderings are created from models as well

11. From Teece

14. From Buchanan and Sousa

17. From Teece

19. Data Mapped Techniques applied to input data and mapped to variables Cartography Scientific Visualization

20. From Agrawala and Stolte

21. From Healey

22. Implementing NPR techniques Pencil and Paper NPR for gaming Toon rendering in real-time NPR Quake

23. Pencil and Paper Rendering Simulating the interaction of paper, pencil lead, eraser, and blender based on an observational model

24. From Buchanan and Sousa

28. Cartoon Rendering Most cartoon rendering involves heavy, dark outlines and flat shading. Some work has been done in stylized cartoon rendering such as Dr. Suess

29. From Kawalski

30. From Sega’s Fur Fighters

31. Creating that Toon Look The silhouette is the edge between a front and back facing polygon For every front facing polygon XOR in 1 into the F field For every back facing polygon XOR in 1 into the B field

32. The Vertex Hash Table VertexVFB 1200300400500 2300500X00 3400500X00 4500X00 5 x00 From Buchanan and Sousa

33. The Vertex Hash Table VertexVFB 1210310400500 2310500X00 3400500X00 4500X00 5 x00 From Buchanan and Sousa P[1,2,3]

34. The Vertex Hash Table VertexVFB 1210300410500 2310500X00 3410500X00 4500X00 5 x00 From Buchanan and Sousa P[1,3,4]

35. The Vertex Hash Table VertexVFB 1210300410500 2310500X00 3411501X00 4501X00 5 x00 From Buchanan and Sousa P[3,4,5]

36. The Vertex Hash Table VertexVFB 1211300411500 2311500X00 3411500X00 4500X00 5 x00 From Buchanan and Sousa Silhouette={(1,2),(2,3),(3,4),(1,4)} Note: (3,1) would not be drawn

37. NPR Quake Intercept OpenGL calls so that the rendering style can be implemented independent of the game engine