1. ADVANCED VISUALIZATION OF ENGINE SIMULATION DATA USING TEXTURE SYNTHESIS AND TOPOLOGICAL ANALYSIS Guoning Chen 1, Robert S. Laramee 2 and Eugene Zhang 1 1.Oregon State University, Corvallis, Oregon, USA. {chengu, zhange}@eecs.oregonstate.edu 2.Swansea University SA2 8PP, Wales, United Kingdom. Laramee@swansea.ac.uk

2. Outline Introduction Vector field background Texture-based vector field visualization Vector field topology extraction Vector field simplification Results Conclusion

3. Introduction Applications Requirement of engine design Current vector field visualization methods

4. Vector Field Background Vector field is a function which associates a vector u time t to each point x of U at time t

5. Vector Field Background, continued The topology of a flow consists of –Fixed points Sources Sinks Saddles center

6. Flow topology –Separatrices Incoming Outgoing –Trajectories gradient-like Vector Field Background, continued

7. Texture-Based Vector Field Visualization Previous work 4) feature based Topology skeleton [Helman&Hesselink] 1)direct Arrow plots, icons 2) geometric Streamline[Jobard et al, Turk et al.] 3) texture based Spot noise[van Wijk], LIC[Cabral&Leedom] UFLIC[Shen &Kao] AUFLIC[Liu et al.] DLIC [Sundquist] LEA [Jobard et al.] UFAC[Weiskopf et al.]

8. Texture-Based Vector Field Visualization, continued Image-Based Flow Visualization (IBFV) Image credit: van Wijk

9. Texture-Based Vector Field Visualization, continued Image Space Advection (ISA) & IBFVS

10. Vector Field Topology Extraction Previous work Fixed point extraction

11. Vector Field Topology Extraction, continue Separatrix calculation

12. Vector Field Simplification Previous work –Non-topology based (NTB) Smoothing vector field potential [Ying et al.] Componentwise smoothing [Alliez et al.] –Topology-based (TB) Pair cancellation [Tricoche and Scheuermann][Zhang et al.]

13. Vector Field Simplification, continued User-guided smoothing (A NTB smoothing) –Componentwise smoothing Before smoothing

14. Vector Field Simplification, continued Componentwise smoothing ? is computed by using mean value coordinates

15. Vector Field Simplification

16. Results

17. Results, continued

18. Performance report 7.644.483.16226886,296 Diesel engine 9.259.090.1656105,192 Gas engine time total(s) time computing separatrices(s) times extracting fixed points (s) # of fixed points # of polygons dataset name ( The experiments are carried out on a PC with 3.6GHZ CPU and 3GB RAM )

19. Acknowledgement We would like to thank Christoph Garth, Konstantin Mischaikow, Juergen Schneider and Greg Turk for their valuable contributions.

20. Thank you!