当前位置: article > 正文

three.js 制作地球标注的两种方法_three-geo

作者：凡人多烦事01 | 2024-02-16 18:12:38

踩

three-geo

一，Sprite精灵标签

效果图：
在这里插入图片描述

//精灵标签--标签永远面向相机
function createTxt(position,name){					
	var texture = new THREE.CanvasTexture(getCanvasFont());
	var fontMesh = new THREE.Sprite(new THREE.SpriteMaterial({map: texture}));
	// 放大
	fontMesh.scale.x = 10;
	fontMesh.scale.y = 5;
	// 在原位置各加 2px ,避免文字与地标重叠
	fontMesh.position.x = (position.x >0 ? position.x+2 : position.x-2);
	fontMesh.position.y = (position.y >0 ? position.y+2 : position.y-2);
	fontMesh.position.z = (position.z >0 ? position.z+2 : position.z-2);
	// fontMesh.position.copy(position);	//原位置				
	scene.add(fontMesh);

	// canvas生成图片实现文字函数
	function getCanvasFont() {						
		let w = 600;
		let h = 300;
		let canvas = document.createElement("canvas");
		let ctx = canvas.getContext('2d');
		canvas.width = w;
		canvas.height = h;
		//制作矩形
		ctx.fillStyle = "red";
		ctx.fillRect(0, 0, w, h)
		//设置文字						
		ctx.fillStyle = "black";
		ctx.font = h/3 + 'px "微软雅黑"';						
		ctx.textAlign = 'center';
		ctx.fillText(name, w/2, h/2+20 )
		return canvas;
					}
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

二，贴图标签

效果图：
在这里插入图片描述

//贴图标签，标签与球面融为一体
function createTextCanvas(position,name) {
	//用canvas生成图片
	let w = 200;
	let h = 100;
	let canvas = document.createElement("canvas");
	let ctx = canvas.getContext('2d');
	canvas.width = w;
	canvas.height = h;
	//左右翻转
	ctx.scale(-1, 1);
	ctx.translate(-w, 0);
	//制作矩形
	ctx.fillStyle = "red";
	ctx.fillRect(0, 0, w, h)
	//设置文字						
	ctx.fillStyle = "black";
	ctx.font = h/2 + 'px "微软雅黑"';
	ctx.textAlign = 'center';
	ctx.fillText(name, h, h/2+20);
	
	//生成图片
	let url = canvas.toDataURL('image/png');
	//几何体--长方形
	let geometry1 = new THREE.PlaneGeometry(6, 3);
	//将图片构建到纹理中
	let material1 = new THREE.MeshBasicMaterial({
		map: new THREE.TextureLoader().load(url),
		side: THREE.DoubleSide, //两面可见
		opacity: 1
	});
	let txtMesh = new THREE.Mesh(geometry1, material1);					
	txtMesh.position.copy(position);				
	txtMesh.lookAt(new THREE.Vector3(0, 0,0));					
	scene.add(txtMesh);
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

三，完整代码

<!DOCTYPE html>
<html>
	<head>
		<title>Threejs实现绘制地球，地理位置标注</title>
		<meta charset="UTF-8">
		<script type="text/javascript" src="js/three.js"></script>
		<script type="text/javascript" src="js/OrbitControls.js"></script>
		<script type="text/javascript" src="js/makeTextSprite.js"></script>
		<style>
			body {
				margin: 0;
				overflow: hidden;
			}
		</style>
	</head>
	<body>
		<div id="dom"></div>
		<script type="text/javascript">
			var scene;
			var camera;
			var renderer;
			var radius = 100; // 地球半径
			var dom = document.getElementById("dom")
			var areas = [{
				name: "中国",
				position: [116.20, 39.55]
			}, {
				name: "中非共和国",
				position: [18.35, 4.23]
			}, {
				name: "智利",
				position: [-70.40, -33.24]
			}, {
				name: "乍得",
				position: [14.59, 12.10]
			}, {
				name: "赞比亚",
				position: [28.16, -15.28]
			}, {
				name: "越南",
				position: [105.55, 21.05]
			}, {
				name: "约旦",
				position: [35.52, 31.57]
			}, {
				name: "维尔京群岛",
				position: [-64.37, 18.27]
			}, {
				name: "英国",
				position: [-0.05, 51.36]
			}];


			function init() {
				// 创建一个场景，它将包含我们所有的元素，如物体，相机和灯光。
				scene = new THREE.Scene();

				// 环境光(颜色，亮度)
				var ambientLight = new THREE.AmbientLight("#ffffff", 1.2);
				scene.add(ambientLight);

				// 创建一个摄像机，它定义了我们正在看的地方
				camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
				// 将摄像机对准场景的中心
				camera.position.set(0, 100, -400);
				camera.lookAt(scene.position);

				// 创建一个渲染器并设置大小，WebGLRenderer将会使用电脑显卡来渲染场景
				renderer = new THREE.WebGLRenderer({
					antialias: true, //是否执行抗锯齿
					logarithmicDepthBuffer: false, //如果要在单个场景中处理巨大的比例差异，就有必要使用。此处要用false，否则文字标签不显示
				});
				renderer.setSize(window.innerWidth, window.innerHeight);
				// renderer.setClearColor(0x000000, 1); //设置背景颜色

				// 设置背景图
				var texture = new THREE.TextureLoader().load('imges/back.jpg');
				scene.background = texture;

				// 显示坐标轴
				var axes = new THREE.AxisHelper(radius);
				scene.add(axes);

				//轨道控制器
				var controls = new THREE.OrbitControls(camera);
				controls.minPolarAngle = 0;
				controls.maxPolarAngle = Math.PI / 1; // 上下翻转范围 0-max度				
				controls.minDistance = 120; // 设置移动的最短距离（默认为零）
				controls.maxDistance = 1000; // 设置移动的最长距离（默认为无穷）				
				controls.update(); // 照相机转动时，必须更新该控制器	

				// 将呈现器的输出添加到HTML元素
				document.getElementById("dom").appendChild(renderer.domElement);

				// 运行函数
				createEarth();
				createAreaPoint();
				renderScene();

				// 创建地球 半径100
				function createEarth() {
					var earthGeo = new THREE.SphereGeometry(radius, 50, 50);
					var earthMater = new THREE.MeshPhongMaterial({
						map: new THREE.TextureLoader().load('imges/earth.jpg'),
						//透明球体
						// transparent: true,
						// depthWrite: false,
						// side: THREE.DoubleSide,
						// blending: THREE.AdditiveBlending,
						// opacity: 0.8,
						// color: 0x03d98e
					});
					var earthMesh = new THREE.Mesh(earthGeo, earthMater);
					scene.add(earthMesh);
				}
				
				// 创建地标
				function createAreaPoint() {
					// 循环创建地标，文字标签
					for (let i = 0, length = areas.length; i < length; i++) {
						const name = areas[i].name
						const position = createPosition(areas[i].position)
						createHexagon(position); // 地标函数
						createTxt(position,name); // 精灵标签函数
						// createTextCanvas(position,name) // 贴图标签函数
					}
				}

				// 经纬度转坐标
				function createPosition(lnglat) {
					let spherical = new THREE.Spherical
					spherical.radius = radius;
					const lng = lnglat[0]
					const lat = lnglat[1]
					const theta = (lng + 90) * (Math.PI / 180)
					const phi = (90 - lat) * (Math.PI / 180)
					spherical.phi = phi; // phi是方位面（水平面）内的角度，范围0~360度
					spherical.theta = theta; // theta是俯仰面（竖直面）内的角度，范围0~180度
					let position = new THREE.Vector3()
					position.setFromSpherical(spherical)
					return position
				}

				// 创建地标标记
				function createHexagon(position) {
					var hexagon = new THREE.Object3D()
					let hexagonLine = new THREE.CircleGeometry(2, 6)
					let hexagonPlane = new THREE.CircleGeometry(1, 6)
					let vertices = hexagonLine.vertices
					vertices.shift() // 第一个节点是中心点
					let material = new THREE.MeshBasicMaterial({
						color: 0xffff00,
						side: THREE.DoubleSide, //让材质单面或者双面显示,前面FrontSide ,背面：BackSide ,双面：DoubleSide
						opacity: 0.5
					})
					let circleLine = new THREE.LineLoop(hexagonLine, material)
					let circlePlane = new THREE.Mesh(hexagonPlane, material)
					circleLine.position.copy(position)
					circlePlane.position.copy(position)
					circlePlane.lookAt(new THREE.Vector3(0, 0, 0))
					circleLine.lookAt(new THREE.Vector3(0, 0, 0))

					hexagon.add(circleLine)
					hexagon.add(circlePlane)
					scene.add(hexagon);
				}

				//贴图标签，标签与球面融为一体
				function createTextCanvas(position,name) {
					//用canvas生成图片
					let w = 200;
					let h = 100;
					let canvas = document.createElement("canvas");
					let ctx = canvas.getContext('2d');
					canvas.width = w;
					canvas.height = h;
					//左右翻转
					ctx.scale(-1, 1);
					ctx.translate(-w, 0);
					//制作矩形
					ctx.fillStyle = "red";
					ctx.fillRect(0, 0, w, h)
					//设置文字						
					ctx.fillStyle = "black";
					ctx.font = h/2 + 'px "微软雅黑"';
					ctx.textAlign = 'center';
					ctx.fillText(name, h, h/2+20);
					
					//生成图片
					let url = canvas.toDataURL('image/png');
					//几何体--长方形
					let geometry1 = new THREE.PlaneGeometry(6, 3);
					//将图片构建到纹理中
					let material1 = new THREE.MeshBasicMaterial({
						map: new THREE.TextureLoader().load(url),
						side: THREE.DoubleSide, //两面可见
						opacity: 1
					});
					let txtMesh = new THREE.Mesh(geometry1, material1);					
					txtMesh.position.copy(position);				
					txtMesh.lookAt(new THREE.Vector3(0, 0,0));					
					scene.add(txtMesh);
				}
				
				//精灵标签--标签永远面向相机
				function createTxt(position,name){					
					var texture = new THREE.CanvasTexture(getCanvasFont());
					var fontMesh = new THREE.Sprite(new THREE.SpriteMaterial({map: texture}));
					// 放大
					fontMesh.scale.x = 10;
					fontMesh.scale.y = 5;
					// 在原位置各加 2px ,避免文字与地标重叠
					fontMesh.position.x = (position.x >0 ? position.x+2 : position.x-2);
					fontMesh.position.y = (position.y >0 ? position.y+2 : position.y-2);
					fontMesh.position.z = (position.z >0 ? position.z+2 : position.z-2);
					// fontMesh.position.copy(position);	//原位置				
					scene.add(fontMesh);

					// canvas生成图片实现文字函数
					function getCanvasFont() {						
						let w = 600;
						let h = 300;
						let canvas = document.createElement("canvas");
						let ctx = canvas.getContext('2d');
						canvas.width = w;
						canvas.height = h;
						//制作矩形
						ctx.fillStyle = "red";
						ctx.fillRect(0, 0, w, h)
						//设置文字						
						ctx.fillStyle = "black";
						ctx.font = h/3 + 'px "微软雅黑"';						
						ctx.textAlign = 'center';
						ctx.fillText(name, w/2, h/2+20 )
						return canvas;
					}
				}

				function renderScene() {
					requestAnimationFrame(renderScene); //循环调用renderScene函数
					renderer.render(scene, camera);
				}
			}

			// 随着窗体的变化修改场景大小
			function onResize() {
				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();
				renderer.setSize(window.innerWidth, window.innerHeight);
			}		

			// 监听窗体调整大小事件
			window.addEventListener('resize', onResize, false);

			/* 页面绘制完后加载,避免页面闪动 */
			window.onload = function() {
				init();
			}
			
		</script>
	</body>
</html>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263

参考文章：http://zuoben.top/#1-12
地球高清全景图： https://www.aliyundrive.com/s/C2kStb7B41c

声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/w/凡人多烦事01/article/detail/95968