1. Procedural Skeletons: Kinematic Extensions to CGA-Shape Grammars Martin Ilčík, Stephan Fiedler Werner Purgathofer, Michael Wimmer Institute of Computer Graphics and Algorithms Vienna University of Technology

2. Preview Procedural modeling Grammars Articulated objects Martin Ilčík 2

3. Procedural modeling ↑ Abstraction ↓ Design costs ↓ Artistic skills ↑ Reusability ↑ Domain knowledge ↓ Local control ↑ Formal theory ↓ Reconstruction Martin Ilčík 3 CityEngine, Pascal Müller

4. Nature vs. Urbanism Elements Survival Jagged Long evolution Regular Short term Planarity Batch changes Martin Ilčík 4 Rome Rebuild, Pascal Müller

5. Split grammars Sets of shapes instead of symbols Large amount of rules and attributes Attribute propagation Rule selection Image based reconstruction Symmetries Visual editing [Wonka et al. 2003] Martin Ilčík 5 image by Peter Wonka

6. CGA grammars Scope to oriented bounding boxes transformation rules splits and repetition absolute and relative scaling component splits Sequential Occlusion Snapping [Müller et al. 2006] [Lipp et al. 2008] Martin Ilčík 6 image by Markus Lipp

7. Procedural modeling of cities Martin Ilčík 7 CityEngine, Pascal Müller

8. Poses and Expressions Pose Expression Semantics Relations Functionality Martin Ilčík 8

9. Poses and Expressions Pose Expression Semantics Relations Functionality Martin Ilčík 9

10. Poses and Expressions Pose Expression Semantics Relations Functionality Martin Ilčík 10

11. Poses and Expressions Pose Expression Semantics Relations Functionality Martin Ilčík 11

12. Poses and Expressions Pose Expression Semantics Relations Functionality Martin Ilčík 12

13. Excavator Example - Basis Martin Ilčík 13

14. Excavator Example - Basis Martin Ilčík 14

15. Excavator Example - Basis Martin Ilčík 15

16. Excavator Example - Basis Martin Ilčík 16

17. Excavator Example - Motor Martin Ilčík 17

18. Excavator Example - Cabin Martin Ilčík 18

19. Excavator Example - Cabin Martin Ilčík 19

20. Excavator Example - Chassis Martin Ilčík 20

21. Excavator Example - Wheels Martin Ilčík 21

22. Excavator Example - Arm Martin Ilčík 22

23. Excavator Example - Arm Martin Ilčík 23

24. Excavator Example - Arm Martin Ilčík 24

25. Excavator Example - Shovel Martin Ilčík 25

26. Excavators Martin Ilčík 26

27. Excavators Martin Ilčík 27

28. Excavators Martin Ilčík 28

29. Excavators Martin Ilčík 29

30. Excavators Martin Ilčík 30

31. Excavators Martin Ilčík 31

32. Pose description Kinematic Shapes Rigid bodies Bones Parent link Children links Martin Ilčík 32

33. Pose description Kinematic Shapes Rigid bodies Bones Parent link Children links Joint Martin Ilčík 33

34. Pose description Kinematic Shapes Rigid bodies Bones Parent link Children links Joint Default pose Martin Ilčík 34

35. Pose description Kinematic Shapes Rigid bodies Bones Parent link Children links Joint Default pose Limited transformations Martin Ilčík 35

36. Pose description Kinematic Shapes Rigid bodies Bones Parent link Children links Joint Default pose Limited transformations Current transformation Martin Ilčík 36

37. Pose description Kinematic Shapes Rigid bodies Bones – Automatic Parent link Children links Joint Default pose Limited transformations Current transformation Martin Ilčík 37

38. Pose description Kinematic Shapes Rigid bodies Bones – Automatic Parent link Children links Joint – Kinematic Rules Default pose Limited transformations Current transformation Martin Ilčík 38

39. Starting configuration Martin Ilčík 39

40. Sequential split Martin Ilčík 40

41. Parallel split Martin Ilčík 41

42. Component split Martin Ilčík 42

43. Properties Kinematic independence Martin Ilčík 43

44. Grammar Example BuildingRoot → Subdiv(“Y”, 3.5){Basement|Floor} Floors → Repeat(“Y”, 3a){Floor} Martin Ilčík 44

45. Grammar Example BuildingRoot → Subdiv(“Y”, 3.5){Basement|Floor} Floors → Repeat(“Y”, 3a){Floor} Floor → Comp(“sidefaces”){FloorFacade} FloorFacade → Repeat(“Y”, 1.5a){WindowPane} Martin Ilčík 45

46. Grammar Example BuildingRoot → Subdiv(“Y”, 3.5){Basement|Floor} Floors → Repeat(“Y”, 3a){Floor} Floor → KinematicRotation(RotLimits,CurrentRot) Comp(“sidefaces”){FloorFacade} FloorFacade → Repeat(“Y”, 1.5a){WindowPane} Martin Ilčík 46

47. Grammar Example Martin Ilčík 47

48. Conclusions Poses enrich semantics Rule based Simple extension to CGA Integration Interactivity Rigging for free Post-processing Martin Ilčík 48

49. Future Work Connectivity preservation Mass and stability Deformations Animation IK Martin Ilčík 49

50. Acknowledgements Johannes Kühetreiber, Frederico Dusberger Daniel Scherzer, Markus Lipp Reviewers FIT-IT Visual Computing Initiative GameWorld Project THANK YOU FOR YOUR ATTENTION Martin Ilčík 50