如何在three.js中的夹点事件上缩放相交的对象。 。？

Question

我目前正在开发一个three.js项目，我在其中使用TrackballControls.js进行相机控制。 在我的场景中，我使用OBJMTLLoader加载了很少的对象。我不得不从场景中选择单个对象，并且需要放大和缩小这些单个对象。我能够使用具有以下功能的鼠标事件来获得结果。

      function onDocumentMouseDown( event ) {

            myobj = null; 
            mouse_obj=null;
            event.preventDefault();
            controls.enabled = false;

            var vector = new THREE.Vector3( mouse.x, mouse.y, 0.5 );
            projector.unprojectVector( vector, camera );

            var raycaster = new THREE.Raycaster( camera.position, vector.sub( camera.position ).normalize() );

            var intersects = raycaster.intersectObjects( objects, true );

            if ( intersects.length > 0 ) {


                SELECTED = intersects[ 0 ].object.parent;
                myobj = intersects[ 0 ].object.parent; // selects the intersected object

                var intersects = raycaster.intersectObject( plane );
                offset.copy( intersects[ 0 ].point ).sub( plane.position );

                container.style.cursor = 'move';

            }

        }

以上代码选择对象，下面的代码放大和缩小滚动事件。

          onRendererScroll = function(event) {
            controls.enabled = true;
            if(myobj!=null)
            {
                    var delta=0;

                    event.preventDefault();
                    event.stopPropagation();

                    //alert(myobj.position.x+ ' ' +event.clientX+ ' ' +myobj.position.y+ ' ' +event.clientY);
                    if ( event.wheelDelta ) { // WebKit / Opera / Explorer 9

                    delta = event.wheelDelta / 40;

                    } else if ( event.detail ) { // Firefox

                    delta = - event.detail / 3;

                    }

                    myobj.scale.x = myobj.scale.x+delta*0.01;
                    myobj.scale.y = myobj.scale.y+delta*0.01;
                    myobj.scale.z = myobj.scale.z+delta*0.01;

            }

        }

但我必须使用触摸事件来实现相同的功能。我试图用这个想法，但不能成功。我试图实现从鼠标事件中获得的相同想法。我正在处理的代码如下。 任何人都可以帮我这个..？我不想调试我的代码。我只想了解它是如何实现的。

      onDocumentTouchMove=function(event) {
            event.preventDefault();

            if (event.touches.length === 2)
            {
            controls.enabled = true;
            mouse.x = (((event.touches[0].pageX-(curX+12))/width)*2-1)-(((event.touches[1].pageX-(curX+12))/width)*2-1);
            mouse.y = (-((event.touches[0].pageY-curY)/height)*2+1)-(-((event.touches[1].pageY-curY)/height)*2+1);

            if(myobj!=null)
            {
                    var delta=0;

                    event.preventDefault();
                    event.stopPropagation();

                    delta=Math.sqrt( mouse.x * mouse.x + mouse.y * mouse.y );

                    myobj.scale.x = myobj.scale.x+delta*0.01;
                    myobj.scale.y = myobj.scale.y+delta*0.01;
                    myobj.scale.z = myobj.scale.z+delta*0.01;

            }
            }

        }


        onDocumentTouchStart=function(event) {
            event.preventDefault();
            controls.enabled = false;

            if (event.touches.length === 1)
            {
            myobj = null;
            var vector = new THREE.Vector3( mouse.x, mouse.y, 0.5 );
            projector.unprojectVector( vector, camera );

            var raycaster = new THREE.Raycaster( camera.position, vector.sub( camera.position ).normalize() );

            var intersects = raycaster.intersectObjects( objects, true );

            if ( intersects.length > 0 ) {

                SELECTED = intersects[ 0 ].object.parent;
                myobj = intersects[ 0 ].object.parent;
                var intersects = raycaster.intersectObject( plane );
                offset.copy( intersects[ 0 ].point ).sub( plane.position );


            }
            }
        }


            onDocumentTouchEnd=function(event) {
            event.preventDefault();
            controls.enabled = false;
            if ( INTERSECTED ) {

                plane.position.copy( INTERSECTED.position );
                SELECTED = null;
            }


        }