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Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Robert S. Laramee
Markus Hadwiger
Helwig Hauser
VRVis Research Center
Vienna, Austria
2 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
OutlineOutline 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Introduction, The CFD ProcessIntroduction, 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Flow Visualization ClassificationFlow Visualization Classification1. 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
System Requirements and GoalsSystem 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Visualization System DesignVisualization System Design
7 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
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 problemone approach: interactive
seeding plane
Geometric Flow VisualizationGeometric Flow Visualization
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The Geometric Flow Visualization SubsystemThe Geometric Flow Visualization Subsystem
The Process the processing
pipeline several
interchangeable components
interactive seeding (requirement)
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The Geometric Flow Visualization SubsystemThe 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
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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 VisualizationTexture-Based Flow Visualization
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The Texture-Based Flow Visualization SubsystemThe Texture-Based Flow Visualization Subsystem
The Process fast frame rates (requirement) effective use of graphics hardware still platform independent (requirement)
12 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
The Texture-Based Flow Visualization SubsystemThe 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Discussion and EvaluationDiscussion and Evaluation
Advantages of a big commercial system:
facilitates combinations of options
some engineering already implemented
more user feedback interdisciplinary can generate revenue
14 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
Discussion and EvaluationDiscussion and Evaluation
Disadvantages of a big system:
steep learning curve, 1000s of files
complexity longer compilation
time longer testing time many user requests
15 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
EvaluationEvaluation 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
ConclusionsConclusionsWe 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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
AcknowledgementsAcknowledgements
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 Design and Implementation of Geometric and Texture-Based Flow Visualization Techniques
What about Feature-Extraction/Detection?What about Feature-Extraction/Detection?
Thank you for the excellent question!
See:http://www.VRVis.at/scivis/laramee/jacket