How to add datgui controls for camera in threejs?

Question

I want to to enable dat-gui controls for the threejs camera in the basic threejs example on this page:

https://github.com/mrdoob/three.js/

var camera, scene, renderer;
var geometry, material, mesh;

init();
animate();

function init() {

    camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 10000 );
    camera.position.z = 1000;

    scene = new THREE.Scene();

    geometry = new THREE.CubeGeometry( 200, 200, 200 );
    material = new THREE.MeshBasicMaterial( { color: 0xff0000, wireframe: true } );

    mesh = new THREE.Mesh( geometry, material );
    scene.add( mesh );

    renderer = new THREE.CanvasRenderer();
    renderer.setSize( window.innerWidth, window.innerHeight );

    document.body.appendChild( renderer.domElement );

}

function animate() {

    // note: three.js includes requestAnimationFrame shim
    requestAnimationFrame( animate );

    mesh.rotation.x += 0.01;
    mesh.rotation.y += 0.02;

    renderer.render( scene, camera );

}

I've tried the following code:

var params = {
    z: 100
}

var gui = new dat.GUI();

gui.add(params, 'z', -500,500).step(5).onChange(function(value){
        changeCameraZ(value);
    });
function changeCameraZ(value){
    camera.position.z = value;
}

which works, but it means that I have to write a new function: changeBlah();

for each three.js variable I wish to change from the GUI. Is there a better, cleaner way of achieving this?

Answer 1

This one-liner should work.

gui.add( params, 'z', -500, 500 ).step(5).onChange( function( value ){ camera.position.z = value; } );

Answer 2

You could also make use of how DAT.gui makes use of references.

gui.add( camera.position , 'z', -500, 500 ).step(5)

and an example

http://jsfiddle.net/2WKqL/2/