threejs - 几何坐标系到屏幕坐标系

时间:2016-07-29 17:39:29

标签: javascript three.js

飞机宽度为800px:

geometry = new THREE.PlaneGeometry( 800, 20, 0, 0 );

material = new THREE.MeshBasicMaterial({ 
    color:0xFFFFFF,
    side:THREE.DoubleSide 
});

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

当我尝试操纵它时,使坐标系统成为其他垃圾

mesh.geometry.vertices[0].setY(0);
mesh.geometry.vertices[0].setX(0);
mesh.geometry.vertices[0].setZ(0);

mesh.geometry.vertices[1].setY(0);
mesh.geometry.vertices[1].setX(800);
mesh.geometry.vertices[1].setZ(0);

mesh.geometry.vertices[2].setY(20);
mesh.geometry.vertices[2].setX(0);
mesh.geometry.vertices[2].setZ(0);

mesh.geometry.vertices[3].setY(20);
mesh.geometry.vertices[3].setX(800);
mesh.geometry.vertices[3].setZ(0);

mesh.geometry.verticesNeedUpdate = true;

我可以将几何对象的坐标系调整到相机框架的坐标系吗?

0px = 0

1 个答案:

答案 0 :(得分:1)

如果这不是您正在寻找的,我道歉。如果你的意思是你需要将3d世界中的vector3位置转换为屏幕上的2d像素位置,这是一个典型的转换:

    getScreenTranslation = function (obj, renderer, camera) {
        var vector = new THREE.Vector3();
        var widthHalf = 0.5 * renderer.context.canvas.width;
        var heightHalf = 0.5 * renderer.context.canvas.height;

        vector.setFromMatrixPosition(obj.matrixWorld);
        vector.project(camera);
        vector.x = vector.x * widthHalf + widthHalf;
        vector.y = -(vector.y * heightHalf) + heightHalf;
        return {
                x: vector.x,
                y: vector.y
        };
   };

请记住,您可能需要在网页中补偿canvas元素的位置。