Authors can design interactivity into a scene that responds to user actions.

A scene can sense when the viewer's cursor is over a shape, has touched a shape, or is dragging atop a shape. A scene can also trigger animations on a viewer's touch, enabling the viewer to move and rotate shapes. There are four main action sensor types: TouchSensor senses touch, SphereSensor senses drags in a spherical way, CylinderSensor senses drags cylindrically, and PlaneSensor senses drags around a plane.

These X3D scenes are adapted directly from the original VRML 2.0 Sourcebook chapter examples. Also available: Introduction to VRML97 SIGGRAPH98 course notes.