Question

我正在关注如何使用光线投射来处理可点击对象的mrdoobs示例。我也查看了许多类似的问题，并尝试了无数的事情。光线投射有效...如果我的距离小于1。

Raycaster设置为接近0且远无穷远（默认值）。我还没有看到任何设置距离的代码示例。

我希望有另一双眼睛。

// snippet
glow.clickables = [];
var cubeGeo = new THREE.CubeGeometry(2, 2, 2);
cubeGeo.computeFaceNormals();
var cube = new THREE.Mesh(cubeGeo, redmat);
cube.position.y = 10;
cube.position.x = 0;
cube.position.z = -12;
cube.overdraw = true;
glow.Vis.scene.add(cube);
glow.clickables.push(cube);
onclick_();

var onclick_ = function() {
    $('#world').on('mousedown', function(e){
        var mouseX = (event.offsetX / $('#world').width()) * 2 - 1;
        var mouseY =  - ( event.offsetY / $('#world').height()) * 2 + 1;
        var vector = new THREE.Vector3(mouseX, mouseY,  0.1); //what should z be set to?
        //console.info(vector); // A vector between -1,1 for both x and y. Z is whatever is set on the line above
        projector.unprojectVector(vector, glow.Vis.camera);
        var conts = glow.Vis.controls.getObject().position; // control 3dObject which the camera is added to.
        var clickRay = new THREE.Raycaster(conts, vector.sub(conts).normalize());
        var intersects = clickRay.intersectObjects(glow.clickables);
        console.info(intersects.length);
        if(intersects.length > 0) {
            alert("Click detected!");
        }
    });
}

Answer 1

以这种方式设置鼠标位置更准确。

        var rect = renderer.domElement.getBoundingClientRect();
        mouse.x = ( ( event.clientX - rect.left ) / rect.width ) * 2 - 1;
        mouse.y = - ( ( event.clientY - rect.top ) / rect.height ) * 2 + 1;

Answer 2

对于鼠标检测（远或近！无论！），请执行以下操作：

把它放在你的全球：

var pointerDetectRay, projector, mouse2D;

将它放在你的init（）函数中：

pointerDetectRay = new THREE.Raycaster();
pointerDetectRay.ray.direction.set(0, -1, 0);
projector = new THREE.Projector();
mouse2D = new THREE.Vector3(0, 0, 0);

将它放在你的render（）循环函数中：

pointerDetectRay = projector.pickingRay(mouse2D.clone(), camera);

这是你的鼠标事件：

function onDocumentMouseMove(event) {
    event.preventDefault();
    mouse2D.x = (event.clientX / window.innerWidth) * 2 - 1;
    mouse2D.y = -(event.clientY / window.innerHeight) * 2 + 1;
}

现在，您希望在鼠标指针下检测对象的每个位置都使用：

var intersects = pointerDetectRay.intersectObjects(scene.children);
if (intersects.length > 0) {
    var intersect = intersects[0];
    // intersect is the object under your mouse!
    // do what ever you want!
}

Answer 3

我使用以下内容，对我来说，适用于更远的距离：

    var projector = new THREE.Projector();
    function onDocumentMouseDown( event ) {

        event.preventDefault();

        var vector = new THREE.Vector3( ( event.clientX / window.innerWidth ) * 2 - 1, - ( event.clientY / window.innerHeight ) * 2 + 1, 0.5 );
        projector.unprojectVector(vector,camera);

        var raycaster = new THREE.Raycaster(camera.position,vector.sub(camera.position).normalize() );
        var intersects = raycaster.intersectObjects( [sphere,cylinder,cube] );

        if ( intersects.length > 0 ) {
            intersects[ 0 ].object.material.transparent=true;
            intersects[ 0 ].object.material.opacity=0.1;
            console.log(intersects[0]);
        }
    }

这只是将第一个选定的对象设置为半透明。完整示例：https://github.com/josdirksen/learning-threejs/blob/master/chapter-09/02-selecting-objects.html

Threejs raycaster只能近距离工作

3 个答案: