Module: Illuminated Streamlines Slice ()

Description:

This module intersects an arbitrary 3D vector field and visualizes its directional structure in the cutting plane using illuminated streamlines (ISL). The streamlines are sparsely seeded such that the underlying plane is still visible. To compute the streamlines, it uses the orthogonal vector field. Because the primal and its orthogonal vector fields are used, the method is called dual streamline seeding. The method was developed at ZIB and is published in the following article:

O. Rosanwo, C. Petz, S. Prohaska, I. Hotz and H.-C. Hege, Dual Streamline Seeding, Proceedings of the IEEE Pacific Visualization Symposium, 2009, pp. 9-16.

The method described there has been extended to the plane by simply triangulating the plane and then applying the same algorithm.

Adjusting position and orientation of the cutting plane is done via the module that Illuminated Streamlines Slice is connected to. Please see the documentation of the Clipping Plane module.

You can also connect this module to other planar modules, such as Slice by changing the Module connection port.

Press the Apply button to start the computation of the stream lines. If no streamlines have been computed yet, nothing will be seen. Note that this button needs to be pressed whenever the stream line parameters have changed. For changing color, lighting etc. this is not required.

Connections:

Data [required]
Vector field to be visualized.

Module [optional]
Module defining the cutting plane in which the streamlines will be computed.

Ports:

Color

This port determines the diffuse color of the streamlines.

View options

Lighting: Controls illumination of lines. If off, constant colored lines are drawn (flat shading).
Animate: Activates particle-like animation. The animation speed may be controlled via the command setAnimationSpeed.

Fade factor

Values smaller than 1 have the effect that line segments become more and more transparent in backward direction.

Transparency

Base transparency of the line segments.

Advanced

Options

If the first option is selected, the separatrices of the planar vector field will be explicitly added to the streamlines. Note that without this option the separatrices will only be used to improve the streamline seeding, and hence, the separatrices are not included in the set of streamlines. By selecting the second option, the streamlines will be pruned when they get too close to each other.

Resolution

This port determines the resolution of the underlying triangular grid and thereby the smoothness of the lines.

Separation distance

This parameter determines the closeness of the streamlines.

Line width

The value of this port determines the width of the streamlines.

Seed

Seed value for the random number generator that distributes the seedpoints. Seed value of 0 triggers a different distribution each time.