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, 2.Swansea University SA2 8PP, Wales, United Kingdom.

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

Introduction Applications Requirement of engine design Current vector field visualization methods

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

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

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

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.]

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

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

Vector Field Topology Extraction Previous work Fixed point extraction

Vector Field Topology Extraction, continue Separatrix calculation

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.]

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

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

Vector Field Simplification

Results

Results, continued

Performance report ,296 Diesel engine ,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 )

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

Thank you!