在HTML中更改three.js背景为透明或其他颜色
参考: Changing three.js background to transparent or another color in HTML
Three.js 是一个基于WebGL的JavaScript库,它使得在网页上创建和显示3D图形变得简单。在使用three.js时,我们可能需要根据不同的设计需求改变场景的背景颜色,或者将其设置为透明。本文将详细介绍如何在HTML中使用three.js更改背景颜色或设置为透明,并提供多个示例代码以供参考。
1. 创建基本的three.js场景
在开始更改背景之前,我们首先需要创建一个基本的three.js场景。以下是一个创建场景、相机和渲染器的基本示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Three.js基本场景 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
2. 设置背景颜色
要设置three.js场景的背景颜色,可以直接设置scene.background
属性。以下是一个设置背景颜色为蓝色的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>设置背景颜色 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
scene.background = new THREE.Color(0x0000ff); // 设置背景颜色为蓝色
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
3. 设置背景为透明
如果我们想要将three.js场景的背景设置为透明,需要在创建WebGLRenderer
时设置alpha
选项为true
,并将scene.background
设置为null
。以下是一个设置背景为透明的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>设置背景透明 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
scene.background = null; // 设置背景为透明
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer({ alpha: true }); // 开启透明背景
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
4. 更改背景为渐变色
在three.js中,我们也可以通过使用THREE.Texture
来创建一个渐变背景。以下是一个创建渐变背景的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>设置渐变背景 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
// 创建渐变纹理
var canvas = document.createElement('canvas');
canvas.width = 128;
canvas.height = 128;
var context = canvas.getContext('2d');
var gradient = context.createLinearGradient(0, 0, 0, 128);
gradient.addColorStop(0, '#ffffff'); // 白色
gradient.addColorStop(1, '#0000ff'); // 蓝色
context.fillStyle = gradient;
context.fillRect(0, 0, canvas.width, canvas.height);
var backgroundTexture = new THREE.CanvasTexture(canvas);
scene.background = backgroundTexture;
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
5. 使用CubeTextureLoader加载立方体纹理作为背景
我们还可以使用THREE.CubeTextureLoader
来加载一组图像,作为场景的立方体纹理背景。以下是一个使用立方体纹理作为背景的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>立方体纹理背景 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
var loader = new THREE.CubeTextureLoader();
var textureCube = loader.load([
'px.jpg', 'nx.jpg',
'py.jpg', 'ny.jpg',
'pz.jpg', 'nz.jpg'
]);
scene.background = textureCube;
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
6. 动态更改背景颜色
我们可以通过编写JavaScript代码来动态更改three.js场景的背景颜色。以下是一个动态更改背景颜色的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>动态更改背景颜色 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 动态更改背景颜色
var colorIndex = 0;
var colors = [0xff0000, 0x00ff00, 0x0000ff]; // 红、绿、蓝
function changeBackground() {
scene.background = new THREE.Color(colors[colorIndex % colors.length]);
colorIndex++;
renderer.render(scene, camera);
}
setInterval(changeBackground, 1000); // 每秒更改一次背景颜色
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
7. 使用ShaderMaterial创建自定义背景
我们可以使用ShaderMaterial
来创建自定义的背景效果。以下是一个使用ShaderMaterial
创建背景的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>自定义Shader背景 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script>
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 创建自定义ShaderMaterial
var customMaterial = new THREE.ShaderMaterial({
uniforms: {},
vertexShader: `
void main() {
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
void main() {
gl_FragColor = vec4(0.5, 0.5, 0.5, 1.0); // 灰色背景
}
`
});
var planeGeometry = new THREE.PlaneGeometry(2, 2);
var plane = new THREE.Mesh(planeGeometry, customMaterial);
scene.add(plane);
// 渲染场景和相机
renderer.render(scene, camera);
</script>
</body>
</html>
Output:
8. 使用Post-processing改变背景
在three.js中,我们可以使用后处理(post-processing)效果来改变背景。以下是一个使用后处理改变背景的示例代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>后处理改变背景 - how2html.com</title>
<style>
body { margin: 0; }
canvas { display: block; }
</style>
</head>
<body>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/postprocessing/EffectComposer.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/postprocessing/RenderPass.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/postprocessing/ShaderPass.js"></script>
<script>
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(75, window.innerWidth/window.innerHeight, 0.1, 1000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// 创建EffectComposer
var composer = new THREE.EffectComposer(renderer);
var renderPass = new THREE.RenderPass(scene, camera);
composer.addPass(renderPass);
// 创建自定义后处理ShaderPass
var myEffect = {
uniforms: {
"tDiffuse": { value: null },
"color": { value: new THREE.Color(0x00ff00) } // 绿色背景
},
vertexShader: `
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
`,
fragmentShader: `
uniform vec3 color;
uniform sampler2D tDiffuse;
varying vec2 vUv;
void main() {
vec4 previousPassColor = texture2D(tDiffuse, vUv);
gl_FragColor = vec4(color, 1.0) * previousPassColor;
}
`
};
var myPass = new THREE.ShaderPass(myEffect);
myPass.renderToScreen = true;
composer.addPass(myPass);
// 动画循环渲染
function animate() {
requestAnimationFrame(animate);
composer.render();
}
animate();
</script>
</body>
</html>
Output:
由于篇幅限制,以上是部分示例代码,每个示例都是独立的,可以直接在HTML文件中运行。这些示例展示了如何在three.js中更改背景颜色或设置为透明,并且每个示例都包含了how2html.com
字符串。通过这些示例,你可以学习到如何在three.js中使用不同的技术来更改场景的背景。