Interaction, Widgets & Selections

Interactive visualization tools in VTK.

Interactor Styles

• Camera manipulation (trackball, joystick, flight)
• Custom interaction modes
• Key and mouse event handling
• Touch and gesture support

3D Widgets

• Implicit function widgets — Plane, box, sphere, cylinder
• Handle widgets — Draggable 3D points
• Measurement widgets — Distance, angle, bi-dimensional
• Annotation widgets — Text, scalar bar, orientation marker
• Contour widgets — Draw contours on surfaces or images
• Spline widgets — Define curves in 3D

Picking and Selection

• Point and cell picking
• Hardware (OpenGL) picking
• Rubber-band selection (area picking)
• Frustum selection
• Extracting selected data for further processing

Event System

• Observer/callback pattern
• Command pattern for undo/redo
• Timer events for animation
• Custom events

Topics Covered

• Setting up interactive 3D widgets
• Responding to user selections
• Creating custom interactor styles
• Integrating with GUI toolkits (Qt, Tk)
• Building interactive data exploration tools