Visualization practice WS2005
Flow-Visualization

Christian Biesinger e0225227
Herbert Blaha e0225745

User Guide:

General features

User interface

This screenshot shows the main user interface of our application. The rendered images are shown in separate windows. New windows can be opened at any time, using the New Window button. See below for a more detailed discussion of the features of this user interface. Note that background, arrows and streamlines can be individually enabled or disabled to form a complete image.

Open File opens a new data file for rendering in the current window; new windows can be opened by clicking new window. show statusbar opens a new Statusbar window; see below.

This window tracks mouse movements and shows for each position the current flow vector as well as the additional data available for that point (interpolated where necessary). It can be opened by clicking the show statusbar checkbox in the main window.

This section allows configuring the rendering of the background. The desired data index to render can be configured. The color is calculated by linear interpolation from red to white in the range (min index, average) and from white to green in the range (average, max index).

This section allows configuring how arrows are drawn. The size of each arrow and the distance between two arrows can be configured independently. Additionally, arrows can be scaled so that they indicate the value of a data item. The data index to render can be specified as well as the range of the data of interest: Only values in the range [min..max] will show an arrow, with a linear interpolation between the two; values outside the range will not be displayed.

This section configures the streamline renderer. There are three interplation methods available (simple Euler interpolation, and 2^nd and 4^th order Runge-Kutta interpolation). The highest quality is achieved using 4^th order Runge-Kutta, but this also takes the longest time to render.

The d_t parameter is an indication of the quality of the rendering. Lower values produce better results at the cost of longer rendering time. This value specifies the distance between two sample points on the stream line.

The placement of the stream lines can also be configured. They can be placed on a regular grid, interactively using mouse clicks, or by finding evenly spaced positions. Regular placement does not give very good results. The d_sep parameter is used mainly by the evenly spaced placing algorithm and specifies the distance between two streamlines. d_test specifies when a streamline is aborted when approaching an existing one; it is a percentage of d_sep.