当鼠标悬停（悬停）在对象上时，鼠标光标应该改变（three.js）答案

【问题标题】：When mouseover (hover) on object the mouse cursor should change ( three.js)当鼠标悬停（悬停）在对象上时，鼠标光标应该改变（three.js）
【发布时间】：2017-08-14 11:45:47
【问题描述】：

我在场景中添加了一个球体和平面几何体，当单击平面几何体时，它链接到一个网站现在，当悬停在平面几何上时，“鼠标光标”应更改为“鼠标指针（手）”，并且当未悬停时在平面几何上，鼠标应保留其原始样式。我尝试使用这个语句 "$('html,body').css('cursor','pointer');"但鼠标光标没有改变悬停，当单击平面几何图形时它会发生变化，并且它的光标不会保持在其原始位置。有人可以帮我解决这个问题。我也上传了代码。

<html>
<head>
<body>
<script type="text/javascript" src="jquery-1.11.3.js"></script>

<script src ="./three.js-master/build/three.js"></script>

<script src ="./three.js-master/examples/js/controls/OrbitControls.js">
</script>
<script src ="./three.js-master/examples/js/renderers/Projector.js">
</script>
<script type="text/javascript" src="math.min.js"></script>



<script type="text/javascript">


window.onload = createsphere();
function createsphere() 
{
var controls,scene,camera,renderer;
var planes = [];
var baseVector = new THREE.Vector3(0, 0, 1);
var camDir = new THREE.Vector3();
var planeLookAt = new THREE.Vector3();
function init() 
{

    var spriteResponse = [];
    spriteResponse[0] = {ID:1, x: 0, y: 0};
    spriteResponse[1] = {ID:2, x: 0, y: 0.1};
    spriteResponse[2] = {ID:3, x: 0, y: 0.5};
    spriteResponse[3] = {ID:4, x: 0.5, y: 0};
    spriteResponse[4] = {ID:5, x: 0.25, y: 0.5 };

    scene = new THREE.Scene();
    camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
    //camera.position.y = 1;
    camera.position.z = 1 ;             
    var width = window.innerWidth;
    var height = window.innerHeight;
    renderer = new THREE.WebGLRenderer( {antialias:true} );
    renderer.setSize(width, height);
    document.body.appendChild(renderer.domElement);      
 /* ------------------------ creating the geometry of sphere------------------------------*/

    var radius = 2.5;
    var spheregeometry = new THREE.SphereGeometry(radius, 20, 20, 0, -6.283, 1, 1);
    //var texture =  THREE.ImageUtils.loadTexture ('rbi00000083.jpg');
    //texture.minFilter = THREE.NearestFilter;
    //var spherematerial = new THREE.MeshBasicMaterial({map: texture});
    var spherematerial = new THREE.MeshBasicMaterial({color: '#A9A9A9'});
    var sphere = new THREE.Mesh(spheregeometry, spherematerial); 
    scene.add(sphere);
    scene.add(camera);
    scene.autoUpdate = true;                
    controls = new THREE.OrbitControls(camera, renderer.domElement);
    controls.minPolarAngle = Math.PI/4;
    controls.maxPolarAngle = 3*Math.PI/4;   

    for(var i=0; i<spriteResponse.length;i++)
    {




        //var spriteAlignment = new THREE.Vector2(0,0) ;
        material_plane = new THREE.MeshBasicMaterial( {color: 0xffffff,side: THREE.DoubleSide } );
        material_plane.needsUpdate = true;
        //material.transparent=true;
        geometry_plane = new THREE.PlaneGeometry(0.3, 0.2);
        plane = new THREE.Mesh( geometry_plane, material_plane );
        plane.database_id = spriteResponse[i].ID;
        plane.LabelText   = spriteResponse[i].name;




        plane.position.set(spriteResponse[i].x,spriteResponse[i].y,-1);



        scene.add(plane);
        //plane.userData = { keepMe: true };
        planes.push(plane);
        //plane.id = cardinal.ID;
        //var direction = camera.getWorldDirection();
        camera.updateMatrixWorld();
        var vector = camera.position.clone();
        vector.applyMatrix3( camera.matrixWorld );
        plane.lookAt(vector);
        plane.userData = { URL: "http://stackoverflow.com"};
        document.addEventListener( 'mousedown', onDocumentMouseDown, false );

    }

    function onDocumentMouseDown( event ) 
    {

        //clearScene();
        event.preventDefault();

        var mouse = new THREE.Vector2();
        mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
        mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;
        var raycaster = new THREE.Raycaster();
        raycaster.setFromCamera( mouse, camera );               
        var intersects = raycaster.intersectObjects( planes );                  

        var matched_marker = null;
        if(intersects.length != 0)
        {
            $('html,body').css('cursor','pointer');//mouse cursor change
            for ( var i = 0;  intersects.length > 0 && i < intersects.length; i++)
            {
                window.open(intersects[0].object.userData.URL);
            }
        }
        else
            $('html,body').css('cursor','cursor');//mouse cursor change
    }//onDocumentMouseDown( event )





}
function animate() 
{
    requestAnimationFrame(animate);
    controls.update();
    renderer.render(scene, camera);
}
init();
animate();


}

</script>
</body>
</head>
</html>

【问题讨论】：

标签： javascript html css three.js hover

【解决方案1】：

您无法在 JS 中更改悬停状态，如下所述：

https://stackoverflow.com/a/11371599/5001964

我认为最简单的解决方案是使用 css：

body:hover {
    cursor: pointer;
}

虽然body你选择一个特定的DOM节点来制作悬停效果会更好。

【讨论】：

【解决方案2】：

有很多方法可以做到这一点，但为了保持简单并让您更容易理解，我的示例包含一个与您在问题中提供的代码格式保持一致的方法。

我在init() function中添加了一个mousemove事件。处理程序如下所示：

function onDocumentMouseMove(event) {

    var mouse = new THREE.Vector2();
    mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
    mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

    var raycaster = new THREE.Raycaster();
    raycaster.setFromCamera( mouse, camera );
    var intersects = raycaster.intersectObjects( planes );

    if(intersects.length > 0) {
        $('html,body').css('cursor', 'pointer');
    } else {
        $('html,body').css('cursor', 'default');
    }

}

所有这一切都是在您每次移动鼠标时检查您的一个平面是否相交。

这之前不起作用的原因是因为您只在鼠标按下时更改了光标，这不会产生所需的“悬停”效果。

Here's a working fiddle。请注意，我已注释掉任何与控件相关的代码以使小提琴更快地工作，它不会改变解决方案。

【讨论】：

没有jQuery：if (intersects && intersects.length > 0) { document.body.style.cursor = 'pointer' } else { document.body.style.cursor = 'default' } span>