TrackballControls

TrackballControls is a JavaScript library that provides an intuitive way to control a 3D camera in a scene, commonly used in conjunction with WebGL frameworks like Three.js. It simulates the behavior of a physical trackball, allowing users to rotate, pan, and zoom the camera by interacting with the mouse or touch input. The primary function of TrackballControls is to translate mouse movements into camera transformations. Dragging the mouse across the screen rotates the camera around a central point. Moving the mouse horizontally typically affects the yaw (rotation around the vertical axis), while vertical movement affects the pitch (rotation around the horizontal axis).

Zooming is usually achieved by scrolling the mouse wheel or by pressing and holding specific mouse buttons while moving the mouse forward or backward. Panning, or moving the camera position without rotation, is often implemented by holding down a different mouse button and dragging. The library offers configurable options to adjust sensitivity, the rotation axis, and the behavior of different mouse buttons for these operations. This makes it adaptable to various application requirements and user preferences. Its ease of integration and natural feel have made it a popular choice for interactive 3D visualizations and applications on the web.