所以，我尝试使用鼠标绘制 3D 矩形。经过几个小时的尝试，我发布了这个问题。
我设法绘制了一个可调整大小的矩形。我通过编辑和更新顶点来做到这一点。
我做了一个jsfiddle:https://jsfiddle.net/bgzrcx46/7/
我在这里遇到一些问题:
- 当我开始拖动时，矩形不会将其自身定位在鼠标所在的位置
- 矩形以错误的方向调整大小(如果您在旋转相机时也能做到这一点，那就太好了)
谁能帮我解决这个问题吗？
如果您想要纯 HTML:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>RSCEDIT - Test</title>
<style>
body {
margin: 0;
padding: 0;
width: 100%;
height: 100%;
}
#main {
width: 100%;
height: 100%;
display: block;
padding: 0;
margin: 0;
}
</style>
</head>
<body>
<div class="container">
<canvas id="main"></canvas>
</div>
<script src="https://rscedit.io/assets/client/js/core/libraries/jquery.min.js"></script>
<script type="text/javascript" src="https://rscedit.io/assets/client/js/threejs/three.min.js"></script>
<script type="text/javascript" src="https://rscedit.io/assets/client/js/threejs/Detector.js"></script>
<script type="text/javascript" src="https://rscedit.io/assets/client/js/threejs/controls/OrbitControls.js"></script>
<script type="text/javascript" src="https://rscedit.io/assets/client/js/threejs/Projector.js"></script>
<script type="text/javascript" src="https://rscedit.io/assets/client/js/threejs/dat.gui.min.js"></script>
<script>
var canvas = document.getElementById('main');
var renderer = new THREE.WebGLRenderer({
canvas: canvas
});
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(45, canvas.clientWidth / canvas.clientHeight, 1, 100000);
var geometry = new THREE.Geometry();
var rayCaster = new THREE.Raycaster();
var controls;
var dragging = false;
var startPosition = {
x: 0,
y: 0
};
var vertexSize = 2;
onLoad();
function onLoad() {
canvas.onmousedown = onMouseDown;
canvas.onmousemove = onDrag;
canvas.onmouseup = onMouseUp;
renderer.setSize(canvas.clientWidth, canvas.clientHeight);
camera.position.set(0, 0, 25.0);
scene.add(camera);
/*
* Create a Rectangle
*/
geometry.vertices.push(new THREE.Vector3(-vertexSize, vertexSize, 0.0));
geometry.vertices.push(new THREE.Vector3(vertexSize, vertexSize, 0.0));
geometry.vertices.push(new THREE.Vector3(vertexSize, -vertexSize, 0.0));
geometry.vertices.push(new THREE.Vector3(-vertexSize, -vertexSize, 0.0));
geometry.faces.push(new THREE.Face3(0, 1, 2));
geometry.faces.push(new THREE.Face3(0, 2, 3));
var material = new THREE.MeshBasicMaterial({
color: 0xDB1E1E,
wireframe: true
});
var mesh = new THREE.Mesh(geometry, material);
mesh.rotation.x = Math.PI / 2;
scene.add(mesh);
var gridSize = 20;
var divisions = 20;
var gridHelper = new THREE.GridHelper(gridSize, divisions);
scene.add(gridHelper);
controls = new THREE.OrbitControls(camera, renderer.domElement);
render();
}
function update(index, x, y) {
geometry.vertices[index].set(x, y, 0);
geometry.verticesNeedUpdate = true;
}
function render() {
requestAnimationFrame(render);
renderer.render(scene, camera);
}
function onMouseDown(e) {
var relative = get3DPosition(e);
if (!relative) {
return;
}
dragging = true;
startPosition.x = e.pageX;
startPosition.y = e.pageY;
scene.children[1].position.set(relative.x + vertexSize, relative.y, relative.z);
controls.enabled = false;
}
function onDrag(e) {
if (dragging) {
var clientX = (e.pageX - startPosition.x) / 50;
var clientY = (e.pageY - startPosition.y) / 50;
var vertices = geometry.vertices;
vertices[1].x = clientX;
vertices[2].x = clientX;
vertices[2].y = -clientY;
vertices[3].y = -clientY;
geometry.verticesNeedUpdate = true;
}
}
function onMouseUp(e) {
dragging = false;
controls.enabled = true;
}
function get3DPosition(event) {
var offset = $(canvas).offset();
var position = {
x: ((event.clientX - offset.left) / canvas.clientWidth) * 2 - 1,
y: -((event.clientY - offset.top) / canvas.clientHeight) * 2 + 1
};
rayCaster.setFromCamera(position, camera);
var intersects = rayCaster.intersectObjects(scene.children, true);
if (intersects.length > 0) {
return intersects[0].point;
}
}
</script>
</body>
</html>
谢谢!
最佳答案
感谢您分享您的 JFiddle!这对我目前正在做的事情会有很大的帮助!!
目前对所有这些编码还是很陌生，但我弄乱了你的 JFiddle 并发现:
- 鼠标到框拖动的准确性受到相机在网格中的位置的影响，因此我将其锁定并将其设置为正交......
- 将“* -1”添加到每个顶点“onDrag”命令中(因为 盒子正在以相反的方向调整自身的大小。
- 将初始框大小设置为0以从鼠标位置拖出
这是要检查的JFiddle，希望对您有所帮助!您随时可以将摄像头调回原来的位置，并将 controls.enabled = false 再次设置为 true。
关于javascript - Three.js 使用鼠标绘制3D矩形，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49597810/