Contextual Snapshots: Enriched Visualization with Interactive Spatial Annotations Peter Mindek 1, Stefan Bruckner 2,1 and M. Eduard Gröller 1 1 Institute of Computer Graphics and Algorithms Vienna University of Technology 2 Department of Informatics University of Bergen

Motivation Peter Mindek 1 Creating spatial selections (brushing) is a ubiquitous tool in visualization.

Selections Peter Mindek 2 Image-Space SelectionObject-Space Selection Image-Space SelectionObject-Space Selection

Motivation Peter Mindek 3 Image-space selections are context-dependant.

Context-Dependancy Peter Mindek 4 Context:

Motivation Brushing implementations usually target one specific purpose No standard way to manage multiple image- space selections in complex environments Peter Mindek 5

Contextual Snapshots Managing image-space selections Keeping context for each selection Providing interface for linked views Transfering selected data between the linked views XML serialization Peter Mindek 6

Contextual Snapshots - Overview Peter Mindek 7

Creating Contextual Snapshots Peter Mindek 8

Recording Selections Peter Mindek 9

10 Displaying Selections A selection displayed by highlighting transitions between selected and unselected areas A selection displayed as an overlay texture

Anchors Visual representation of contextual snapshots Switching the stored system states Contain screenshot of the system Peter Mindek 11

Embedded Visualizations Peter Mindek 12

Peter Mindek 13 Overview of the System

Conclusions Concept for enhancing visualization systems Image-space selection management in changing context Data transfer for effective utilization of the selections, e.g., for brushing and linking Implementation as a reusable library Peter Mindek 15

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Linked Views Each selection can be linked with additional views – embedded visualizations Arbitrary data can be extracted from the visualization system for each selection Weighted by the selection mask Stored in float textures on the GPU Interactive Implemented by the visualization system Embedded into the original visualization Peter Mindek 17

Selections 2D spatial selections Smooth brushing Displayed only when their contextual snapshot is active Universal implementation Selection mask shaders Selection display shaders Peter Mindek 18

Peter Mindek 19 Selection Masks A selection stroke transformed to a fuzzy lasso selection A selection stroke transformed to a square selection