Simulation in Computer Graphics. Introduction. Matthias Teschner. Computer Science Department University of Freiburg

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1 Simulation in Computer Graphics Introduction Matthias Teschner Computer Science Department University of Freiburg

2 Contact Matthias Teschner Computer Graphics University of Freiburg Georges-Koehler-Allee 052 / teschner@informatik.uni-freiburg.de -> teaching University of Freiburg Computer Science Department Computer Graphics - 2

3 Course Information key course pattern recognition and computer graphics (rasterization-based rendering) specialization courses advanced computer graphics (ray tracing) simulation in computer graphics (e.g., fluids) master project, lab course, Master thesis two tracks: simulation, rendering University of Freiburg Computer Science Department Computer Graphics - 3

4 Seminars / Projects / Theses in Graphics Semester Simulation Track Rendering Track Winter Summer Winter Summer Rasterization Course Simulation Course Lab Course - simple fluid solver Simulation Seminar Master Project - PPE fluid solver Master Thesis - research-oriented topic Rasterization Course Raytracing Course Lab Course - simple raytracer Master Project - Monte Carlo raytracer Rendering Seminar Master Thesis - research-oriented topic University of Freiburg Computer Science Department Computer Graphics - 4

5 Outline motivation topics overview organization University of Freiburg Computer Science Department Computer Graphics - 5

6 Course Goals physically-based animation of the dynamics of rigid bodies deformable objects fluids rigid bodies fluids deformable objects 1D, 2D, 3D University of Freiburg Computer Science Department Computer Graphics - 6

7 Course Goals interplay of simulation components model generation collision detection, contact handling, constraints effects mesh generation contact handling constraints phase transition University of Freiburg Computer Science Department Computer Graphics - 7

8 Applications computational medicine pre-operative planning in cranio-maxillofacial surgery interactive hystersocopy simulation for educational purposes intra-operative support in orbital reconstruction University of Freiburg Computer Science Department Computer Graphics - 8

9 Applications robotics support of robot navigation in environments with deformable objects acceleration of robot navigation with simulation environments University of Freiburg Computer Science Department Computer Graphics - 9

10 Applications entertainment technologies ATI (Havok) NVIDIA (PhysX) Crytek (CryEngine) Pixar Ubisoft University of Freiburg Computer Science Department Computer Graphics - 10

11 Applications entertainment technologies interactive dynamic animations physically-plausible robust versatile focus on the interplay of different animation aspects model generation dynamics collision handling constraints interacting deformable objects University of Freiburg Computer Science Department Computer Graphics - 11

12 Applications animation (with Pixar) University of Freiburg Computer Science Department Computer Graphics - 12

13 Applications automotive (with Fifty2) University of Freiburg Computer Science Department Computer Graphics - 13

14 Conventional and Physically-based Animation conventional animation keyframes, interpolation fully controllable predefined, non-interactive physically-based animation driven by physical laws computed in real time interactive University of Freiburg Computer Science Department Computer Graphics - 14

15 Scientific Computations and Physically-based Animation scientific computing / computational physics reproduction of natural phenomena substitute for real experiments physically-based animation imitation of physical phenomena plausible behavior as much realism as possible within speed and stability constraints focus on data structures and algorithms University of Freiburg Computer Science Department Computer Graphics - 15

16 Outline motivation topics overview organization University of Freiburg Computer Science Department Computer Graphics - 16

17 Topics particle systems mass-point systems fluids rigid bodies collision detection University of Freiburg Computer Science Department Computer Graphics - 17

18 Particle Systems collection of many small simple particles with mass m, position x, velocity v particle motion influenced by force F dynamics governed by F=ma time integration to compute position and velocity over time v x m F generator University of Freiburg Computer Science Department Computer Graphics - 18

19 Particle Systems snow, dust, sand fire smoke University of Freiburg Computer Science Department Computer Graphics - 19

20 Mass-Point Models discretization of an object into mass points representation of forces between mass points with springs force-deformation relation, topology, constraints, damping University of Freiburg Computer Science Department Computer Graphics - 20

21 Generalized Spring Forces deformation based on constraints distance preservation area preservation, surface tension volume preservation wide range of material stiffness melting fluid-like behavior University of Freiburg Computer Science Department Computer Graphics - 21

22 Geometric Constraints restrict the motion of mass points keep a mass point at a position force a point onto a curve or surface University of Freiburg Computer Science Department Computer Graphics - 22

23 Fluids Lagrangian approach Eulerian approach velocities computed on moving particles information advected with particles velocities computed on a fixed grid grid cells represent information University of Freiburg Computer Science Department Computer Graphics - 24

24 Fluids Lagrangian Approach 3 Ships Fluid simulation with 20 million particles University of Freiburg Computer Science Department Computer Graphics - 25

25 Fluids Lagrangian Approach University of Freiburg Computer Science Department Computer Graphics - 26

26 Fluids Lagrangian Approach 3 Ships Fluid simulation with 20 million particles University of Freiburg Computer Science Department Computer Graphics - 27

27 Rigid Bodies mass points connected by springs with infinite stiffness entire body described by position and orientation forces at mass points cause translation and rotation of entire body University of Freiburg Computer Science Department Computer Graphics - 28

28 Topics particle systems mass-point systems fluids rigid bodies collision detection University of Freiburg Computer Science Department Computer Graphics - 29

29 Collision Detection detecting interferences of objects rigid objects represented as triangulated surfaces avoiding time-consuming triangle-triangle intersection tests using pre-computed data structures bounding volumes, space subdivision, distance fields University of Freiburg Computer Science Department Computer Graphics - 30

30 Collision Handling for Deformable Objects Spillmann, Freiburg University of Freiburg Computer Science Department Computer Graphics - 31

31 Tentative Course Syllabus particles ordinary differential equations mass-point systems deformable objects stability constraints fluids mostly Lagrangian rigid bodies collision detection spatial data structures University of Freiburg Computer Science Department Computer Graphics - 34

32 Outline motivation topics overview organization University of Freiburg Computer Science Department Computer Graphics - 35

33 Exercises / Exam exercises by appointment first exercise on Oct 20 smaller exercises in the first part larger project towards the end exam oral exam based on slide sets University of Freiburg Computer Science Department Computer Graphics - 36

34 Simulation in Computer Graphics Introduction Matthias Teschner Computer Science Department University of Freiburg