ArcballControls

Arcball controls move the camera with a virtual trackball, with full touch support and advanced navigation. Mirrors EASEL.js r186 ArcballControls. Cursor and finger movements map onto a virtual trackball surface, shown by the gizmos, so dragging orbits the camera around the trackball center in a conservative way: returning to the starting point restores the starting orientation. With the default {@link ArcballControls.mouseActions}: - Rotate: left mouse; one-finger drag; two-finger twist rotates about the view direction. - Pan: right mouse or ctrl/meta + left mouse; two-finger drag. - Zoom: middle mouse drag or wheel; two-finger pinch. - FOV (perspective only): shift + middle mouse drag or shift + wheel; three-finger vertical drag. - Focus: double click or double tap on a mesh in scene. Unlike orbit controls, update() does not need to run every frame: focus and rotation inertia animate through requestAnimationFrame. Without requestAnimationFrame, those operations complete immediately instead. Dispatches change when the camera or gizmos change, start when an interaction begins, and end when it ends.