Flow - Visualisation


LU Visualisierung - Beispiel 2, WS 2002/2003

by

Thomas Rongitsch (e9825730@stud3.tuwien.ac.at)

Fabian Bendix (e9825733@stud3.tuwien.ac.at)

 

download source (kontaktiere die Übungsleitung)

view program

Technical Documentation


Introduction

Features

Transfer Function

Arrow Plot

Evenly Spaced Streamlines

 

Introduction

 

Within the scope of the LU Visualisierung at the ICGA we implemented a flow visualisation tool. This means that an image is generated without any geometric primitives. A large dataset that contains information about - let's say - a river delivers the whole information about the picture. On the one hand this tool can draw an arrowplot and on the other hand it draws a streamlines.

 

The task was ..

1) .. to draw an arrowplot

2) .. to draw evenly spaced streamlines

3) .. to color the additional parameters (pressure and vorticity)

4) .. develop an application with a lot of interaction possibilities

5) .. to achieve significant images

 

Features

 

- Arrowplot: texturized arrows and untexturized arrows

- streamlines calculated by Euler Integration and Runge Kutta 2 Integration

- control over density and size

- editable Transferfunctions for pressure and vorticity

- different Vector interpolation types

- Tapering

- Texture generation

 

Transfer Function

 

The program provides an easy way to edit the mapping for pressure and vorticity values in the flow data. Two independent Dialogs implemtent this functionality (see below).

It is also possible to load and store the current state of the transfer function to ease the handling.

 

Transfer Function

with a loaded color mapping

 

Arrowplot

 

Below you can see some sample images genrated by our application. Due to demonstration issues we have tried to vary the parameters as much as possible.

 

Density = 9.1%
Arrowlength = 65.1%
untextured arrows
arrows are not equallized

 

Density = 9.1%
Arrowlength = 65.1%
textured arrows
arrows are not equallized

 

Density = 6.2%
Arrowlength = 92.2%
untextured arrows
arrows are equallized

 

Density = 6.2%
Arrowlength = 92.2%
textured arrows
arrows are equallized

 

different Transferfunctions

 

different Transferfunctions

 

 

Evenly Spaced Streamlines

 

The following section gives you an overview about the streamlines this application can do. The difference between images with tapering and images without tapering; differences in the kind of integration and differences in the kind of interpolation are illustrated.

 

Density = 3.5%
DSep = 44.1%
DT = 68.3%
without Tapering

 

Density = 3.5%
DSep = 44.1%
DT = 68.3%
with Tapering

 

Density = 2.5%
DSep = 44.1%
DT = 68.3%
Euler Integration

 

Density = 2.5%
DSep = 44.1%
DT = 68.3%
Runge Kutta 2 Integration

 

Density = 2.5%
DSep = 50%
DT = 67.1%
Runge Kutta 2 Integration

 

Density = 2.5%
DSep = 98.4%
DT = 67.1%
Runge Kutta 2 Integration