A sketch-based interface for classifying and visualizing vector fields

Abstract

In flow visualization, field lines are often used to convey both global and local structure and movement of the flow. One challenge is to find and classify the representative field lines. Most existing solutions follow an automatic approach that generates field lines characterizing the flow and arranges these lines into a single picture. In our work, we advocate a user-centric approach to exploring 3D vector fields. Our method allows the user to sketch 2D curves for pattern matching in 2D and field lines clustering in 3D. Specifically, a 3D field line whose view-dependent 2D projection is most similar to the user drawing will be identified and utilized to extract all similar 3D field lines. Furthermore, we employ an automatic clustering method to generate field-line templates for the user to locate subfields of interest. This semi-automatic process leverages the user's knowledge about the flow field through intuitive user interaction, resulting in a promising alternative to existing flow visualization solutions. With our sketch-based interface, the user can effectively dissect the flow field and make more structured visualization for analysis or presentation.

FlowString: Partial Streamline Matching Using Shape Invariant Similarity Measure for Exploratory Flow Visualization

“…Closely related to our work are the work of Schlemmer et al [15], Wei et al [20], and Lu et al [10]. Schlemmer et al [15] leveraged moment invariants to detect 2D flow features which are invariant under translation, scaling and rotation.…”

“…Therefore, they are often used for more robust similarity measuring. In other approaches, the similarity between integral curves are measured in a transformed feature space [1,20,14].…”

“…However, their work is restrictive to 2D flow fields and patterns are detected based on local neighborhoods rather than integral curves. Wei et al [20] extracted features along reparameterized streamlines at equal arc length and used the edit distance to measure streamline similarity. Features of varying scales are only roughly captured by simply recording the length of each resampled streamline.…”

Comparative Visual Analysis of Lagrangian Transport in CFD Ensembles

“…Hereby comparisons are not performed on data at a specific location, but over a set of features present in the flow field. Similarities can then be defined by the presence or absence of common feature types, shapes, or properties (see for example [32,19] for feature based similarity metrics in flow fields). The techniques presented in this paper represent a hybrid method -comparisons are performed in data-space, while relying on the transport property computed from flow trajectories.…”

FlowGraph: A compound hierarchical graph for flow field exploration

“…Their interface design strikes a good balance between supporting artistic freedom and maintaining the accuracy with respect to the underlying vector field data. Wei et al [24] targeted 3D flow fields and presented a solution that allows the user to sketch a 2D curve for pattern matching in 2D and streamline clustering in 3D. They also explored another way that creates streamline templates hierarchically to support on-the-fly partial streamline matching in a progressive manner.…”