[javascript] Rotate camera in Three.js with mouse

This might serve as a good starting point for moving/rotating/zooming a camera with mouse/trackpad (in typescript):

class CameraControl {
    zoomMode: boolean = false
    press: boolean = false
    sensitivity: number = 0.02

    constructor(renderer: Three.Renderer, public camera: Three.PerspectiveCamera, updateCallback:() => void){
        renderer.domElement.addEventListener('mousemove', event => {
            if(!this.press){ return }

            if(event.button == 0){
                camera.position.y -= event.movementY * this.sensitivity
                camera.position.x -= event.movementX * this.sensitivity        
            } else if(event.button == 2){
                camera.quaternion.y -= event.movementX * this.sensitivity/10
                camera.quaternion.x -= event.movementY * this.sensitivity/10
            }

            updateCallback()
        })    

        renderer.domElement.addEventListener('mousedown', () => { this.press = true })
        renderer.domElement.addEventListener('mouseup', () => { this.press = false })
        renderer.domElement.addEventListener('mouseleave', () => { this.press = false })

        document.addEventListener('keydown', event => {
            if(event.key == 'Shift'){
                this.zoomMode = true
            }
        })

        document.addEventListener('keyup', event => {
            if(event.key == 'Shift'){
                this.zoomMode = false
            }
        })

        renderer.domElement.addEventListener('mousewheel', event => {
            if(this.zoomMode){ 
                camera.fov += event.wheelDelta * this.sensitivity
                camera.updateProjectionMatrix()
            } else {
                camera.position.z += event.wheelDelta * this.sensitivity
            }

            updateCallback()
        })
    }
}

drop it in like:

this.cameraControl = new CameraControl(renderer, camera, () => {
    // you might want to rerender on camera update if you are not rerendering all the time
    window.requestAnimationFrame(() => renderer.render(scene, camera))
})

Controls:

• move while [holding mouse left / single finger on trackpad] to move camera in x/y plane
• move [mouse wheel / two fingers on trackpad] to move up/down in z-direction
• hold shift + [mouse wheel / two fingers on trackpad] to zoom in/out via increasing/decreasing field-of-view
• move while holding [mouse right / two fingers on trackpad] to rotate the camera (quaternion)

Additionally:

If you want to kinda zoom by changing the 'distance' (along yz) instead of changing field-of-view you can bump up/down camera's position y and z while keeping the ratio of position's y and z unchanged like:

// in mousewheel event listener in zoom mode
const ratio = camera.position.y / camera.position.z
camera.position.y += (event.wheelDelta * this.sensitivity * ratio)
camera.position.z += (event.wheelDelta * this.sensitivity)