使用 Three.js 创建飞线效果，使用自定义着色器实现飞线动画和颜色渐变。

function addflyline(minx, maxx, colorf, colort) {
    var colorf = colorf || {
        r: 0.0,
        g: 0.0,
        b: 0.0,
    };
    var colort = colort || {
        r: 1.0,
        g: 1.0,
        b: 1.0,
    };
    var curve = new THREE.CubicBezierCurve3(
        new THREE.Vector3(minx, 0, minx),
        new THREE.Vector3(minx / 2, (maxx % 70) + 100, maxx / 2),
        new THREE.Vector3(maxx / 2, (maxx % 70) + 70, maxx / 2),
        new THREE.Vector3(maxx, 0, maxx)
    );
    var points = curve.getPoints((maxx - minx) * 5);
    var geometry = new THREE.BufferGeometry().setFromPoints(points);
    var material = createMaterial();
    var flyline = new THREE.Points(geometry, material);
    flyline.material.uniforms.time.value = minx;
    flyline.material.uniforms.colorf = {
        type: "v3",
        value: new THREE.Vector3(colorf.r, colorf.g, colorf.b),
    };
    flyline.material.uniforms.colort = {
        type: "v3",
        value: new THREE.Vector3(colort.r, colort.g, colort.b),
    };

    flyline.minx = minx;
    flyline.maxx = maxx;
    linegroup.push(flyline);
    scene.add(flyline);
}

function createMaterial() {
    var vertShader = `
        uniform float time;
        uniform float size;
        varying vec3 iPosition;

        void main(){
            iPosition = vec3(position);
            float pointsize = 1.;
            if(position.x > time && position.x < (time + size)){
                pointsize = (position.x - time) / size;
            }
            gl_PointSize = pointsize * 3.0;
            gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
        }
    `;
    var fragShader = `
        uniform float time;
        uniform float size;
        uniform vec3 colorf;
        uniform vec3 colort;

        varying vec3 iPosition;

        void main(void) {
            float end = time + size;
            vec4 color;
            if(iPosition.x > time && iPosition.x < end){
                float t = (iPosition.x - time) / size;
                color = vec4(mix(colorf, colort, t), 1.0);
            } else {
                discard;
            }
            gl_FragColor = color;
        }
    `;
    
    return new THREE.ShaderMaterial({
        uniforms: {
            time: { value: 0 },
            size: { value: 10 },
            colorf: { value: new THREE.Vector3(0, 0, 0) },
            colort: { value: new THREE.Vector3(1, 1, 1) }
        },
        vertexShader: vertShader,
        fragmentShader: fragShader,
        transparent: true
    });
}