1. http://www.VRVis.at/ Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Robert S. Laramee Markus Hadwiger Helwig Hauser VRVis Research Center Vienna, Austria

2. 2Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.atOutline introduction: CFD and our goals classification: direct, geometric, texture-based flow visualization system requirements and goals visualization system design subsystem design and implementation the geometric flow visualization sub-system the texture-based flow visualization sub- system discussion and evaluation summary, conclusions, acknowledgements, questions (+ answers)

3. 3Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at Introduction, The CFD Process all research work was carried out within a commercial system for visualization of computational fluid dynamics (CFD) simulation data goal: convey consequences of research prototype within industry level system, i.e., strategies used, advantages and disadvantages

4. 4Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at Flow Visualization Classification 1. direct: overview of vector field, minimal computation, e.g. glyphs, color map 2. texture-based: complete coverage, more computation time, implementation time, e.g., Spot Noise, LIC 3. geometric: compute a discrete object whose geometry reflects flow characteristics, e.g. streamlines

5. 5Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at System Requirements and Goals interactivity platform independence support for a wide range of simulation data sets support for versatile CFD grids tools that address perceptual challenges of 3D flow visualization

6. 6Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at Visualization System Design

7. 7Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at geometric techniques are especially applicable to 3D flow a geometry is computed that reflects the properties of the flow example: a streamline-a line that is everywhere tangent to the flow seeding is a problem one approach: interactive seeding plane Geometric Flow Visualization

8. 8Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at The Geometric Flow Visualization Subsystem The Process the processing pipeline several interchangeable components interactive seeding (requirement)

9. 9Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at The Geometric Flow Visualization Subsystem The Design a class hierarchy of rendering options children inherit features of parents facilitates extensions object-oriented methodology affords developers independence

10. 10Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at problem with geometric approaches: do not provide complete coverage of vector field texture-based approaches do a texture is computed that reflects the properties of the flow problems with previous texture-based approaches: computation time limited to 2D Texture-Based Flow Visualization

11. 11Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at The Texture-Based Flow Visualization Subsystem The Process fast frame rates (requirement) effective use of graphics hardware still platform independent (requirement)

12. 12Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at The Texture-Based Flow Visualization Subsystem The design composition relationships are shown e.g. Textures are- part-of a Texture Stack design process essential for large, stable, and robust software

13. 13Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at Discussion and Evaluation Advantages of a big commercial system: facilitates combinations of options some engineering already implemented more user feedback interdisciplinary can generate revenue

14. 14Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at Discussion and Evaluation Disadvantages of a big system: steep learning curve, 1000s of files complexity longer compilation time longer testing time many user requests

15. 15Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.atEvaluation We achieved interactivity through design choices and intelligent algorithms platform independence realized by using platform independent libraries, e.g. FOX and OpenGL 1.1. versatility achieved through thorough many user options and testing, i.e., many users, many data sets tools that address perceptual challenges in 3D: key interactivity and user options

16. 16Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.atConclusions We presented how we incorporated research work into an industry grade software project. incorporating research software into a commercial system is possible (but not easy) many advantages and disadvantages more requirements than research prototypes alone intelligent design choices required object-oriented methodology-very helpful if not essential

17. 17Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.atAcknowledgements Thank you for your attention! Questions? This work was supported by the Austrian national program Kplus (kplus.at) and AVL (avl.com). CFD simulation data courtesy of AVL. For more information, please visit: http://www.VRVis.at/scivis/

18. 18Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques Laramee@VRVis.at What about Feature-Extraction/Detection? Thank you for the excellent question! See: http://www.VRVis.at/scivis/laramee/jacket