问题描述
我制作了new THREE.PlaneBufferGeometry(100,100,100);
,并且能够更新顶点的位置以更改网格的形状,如下所示:
我通过以下讨论实现了这一目标:Threejs drag points
我在寻找什么?
我希望能够拉伸一张脸(抓住4个顶点),所以我实现了以下目标:
我想将其全部保留在同一网格中,以保持其清洁,因为我将使用ColladaExporter
将其导出为单个网格。
修改
为了实现这一点,我需要克隆顶点并将其向上拉伸。这意味着添加4个新顶点并将它们连接在一起。
我尝试过:
var geo = new THREE.PlaneBufferGeometry(1,1,1);
geo.rotateX(-Math.PI * 0.5);
geo.translate(0,0.5,0);
//And the merge them together
var newplane = BufferGeometryUtils.mergeBufferGeometries([plane,geo]);
newplane = BufferGeometryUtils.mergeVertices(newplane,1);
我明白了:
我希望所有顶点都与平面合并,从而留下一个平面。我这样做是出于测试目的,但它只合并了一个角。
我开始构建具有多个的“多维数据集”并将它们放置在正确的位置,然后再次应用BufferGeometryUtils.mergeVertices
,但顶点似乎无法正确合并:
编辑2 /进度
我设法创建了PlaneBufferGeometry
并通过手动修改顶点和法线来拉伸,如https://threejs.org/docs/#api/en/core/BufferGeometry
拉伸平面连接了所有顶点,因此,每当我拖动一个顶点时,它都会拖动整块,现在的问题是我需要将这些新顶点连接到原始网格,以避免这种情况:
目标是合并所有顶点,现在我需要找到一种方法将基础平面与新的拉伸零件合并。
编辑3 /完成
我成功了,我会在有空的时候发布答案。我今天整天都花这些时间,已经很累了。
解决方法
不确定是否正是您所需要的,但这是您所参考答案的修改示例(请注意mouseMove实现的不同)。我仅将其扩展了两点,但我相信您应该明白这一点:
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60,window.innerWidth / window.innerHeight,1,1000);
camera.position.set(1.25,7,7);
camera.lookAt(scene.position);
var renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth,window.innerHeight);
document.body.appendChild(renderer.domElement);
var geometry = new THREE.PlaneBufferGeometry(10,10,10);
geometry.rotateX(-Math.PI * 0.5);
var plane = new THREE.Mesh(geometry,new THREE.MeshBasicMaterial({
wireframe: true,color: "red"
}));
scene.add(plane);
var points = new THREE.Points(geometry,new THREE.PointsMaterial({
size: 0.25,color: "yellow"
}));
scene.add(points);
var raycaster = new THREE.Raycaster();
raycaster.params.Points.threshold = 0.25;
var mouse = new THREE.Vector2();
var intersects = null;
var plane = new THREE.Plane();
var planeNormal = new THREE.Vector3();
var currentIndex = null;
var planePoint = new THREE.Vector3();
var dragging = false;
window.addEventListener("mousedown",mouseDown,false);
window.addEventListener("mousemove",mouseMove,false);
window.addEventListener("mouseup",mouseUp,false);
function mouseDown(event) {
setRaycaster(event);
getIndex();
dragging = true;
}
function mouseMove(event) {
if (dragging && currentIndex !== null) {
setRaycaster(event);
raycaster.ray.intersectPlane(plane,planePoint);
var indicesToMoveUp = [currentIndex-1,currentIndex];
var delta_x = geometry.attributes.position.getX(currentIndex) - planePoint.x;
geometry.attributes.position.setXYZ(currentIndex,planePoint.x,planePoint.y,planePoint.z);
geometry.attributes.position.needsUpdate = true;
var old_x_neighbour = geometry.attributes.position.getX(currentIndex - 1);
geometry.attributes.position.setY(currentIndex-1,planePoint.y);
geometry.attributes.position.setZ(currentIndex-1,planePoint.z);
geometry.attributes.position.setX(currentIndex-1,old_x_neighbour - delta_x);
geometry.attributes.position.needsUpdate = true;
}
}
function mouseUp(event) {
dragging = false;
currentIndex = null;
}
function getIndex() {
intersects = raycaster.intersectObject(points);
if (intersects.length === 0) {
currentIndex = null;
return;
}
currentIndex = intersects[0].index;
setPlane(intersects[0].point);
}
function setPlane(point) {
planeNormal.subVectors(camera.position,point).normalize();
plane.setFromNormalAndCoplanarPoint(planeNormal,point);
}
function setRaycaster(event) {
getMouse(event);
raycaster.setFromCamera(mouse,camera);
}
function getMouse(event) {
mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;
}
render();
function render() {
requestAnimationFrame(render);
renderer.render(scene,camera);
}
body {
overflow: hidden;
margin: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/91/three.min.js"></script>