nanocode/particle-lab/05-helix/index.html

<!DOCTYPE html>
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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>05 - HELIX | 双螺旋 DNA</title>
    <style>
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { background: #000; overflow: hidden; font-family: 'Space Mono', monospace; }
        #canvas-container { width: 100vw; height: 100vh; }
        .info {
            position: fixed; top: 20px; left: 20px; color: #00d4ff;
            font-size: 14px; pointer-events: none; z-index: 100;
            text-shadow: 0 0 10px rgba(0,212,255,0.5);
        }
        .info h1 { font-size: 20px; margin-bottom: 8px; }
        .info p { opacity: 0.8; font-size: 12px; margin: 4px 0; }
        .controls {
            position: fixed; bottom: 20px; left: 20px; color: #fff;
            font-size: 12px; background: rgba(0,0,0,0.7); padding: 15px;
            border-radius: 8px; border: 1px solid #333; backdrop-filter: blur(10px);
        }
        .control-group { margin: 10px 0; display: flex; align-items: center; gap: 10px; }
        .control-group label { width: 80px; color: #aaa; }
        .control-group input[type="range"] { width: 120px; }
        .control-group span { color: #00d4ff; min-width: 40px; }
    </style>
</head>
<body>
    <div id="canvas-container"></div>
    <div class="info">
        <h1>05 - HELIX</h1>
        <p>双螺旋 DNA 结构</p>
        <p>粒子数: <span id="count">0</span></p>
        <p>FPS: <span id="fps">0</span></p>
    </div>
    <div class="controls">
        <div class="control-group">
            <label>螺旋半径</label>
            <input type="range" id="radius" min="5" max="20" step="0.5" value="12">
            <span id="radVal">12</span>
        </div>
        <div class="control-group">
            <label>螺旋高度</label>
            <input type="range" id="height" min="40" max="100" step="5" value="60">
            <span id="htVal">60</span>
        </div>
        <div class="control-group">
            <label>旋转速度</label>
            <input type="range" id="twist" min="1" max="10" step="0.5" value="4">
            <span id="twistVal">4</span>
        </div>
    </div>

    <script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r128/three.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/controls/OrbitControls.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/postprocessing/EffectComposer.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/postprocessing/RenderPass.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/postprocessing/ShaderPass.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/shaders/CopyShader.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/shaders/LuminosityHighPassShader.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/three@0.128.0/examples/js/postprocessing/UnrealBloomPass.js"></script>

    <script>
        const COUNT = 6000; // 双链，每链3000
        const scene = new THREE.Scene();
        scene.fog = new THREE.FogExp2(0x000000, 0.01);
        const camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 0.1, 2000);
        camera.position.set(0, 0, 100);
        const renderer = new THREE.WebGLRenderer({ antialias: true, powerPreference: "high-performance" });
        renderer.setSize(window.innerWidth, window.innerHeight);
        renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2));
        document.getElementById('canvas-container').appendChild(renderer.domElement);

        const controls = new THREE.OrbitControls(camera, renderer.domElement);
        controls.enableDamping = true;
        controls.autoRotate = true;
        controls.autoRotateSpeed = 0.5;

        const renderScene = new THREE.RenderPass(scene, camera);
        const bloomPass = new THREE.UnrealBloomPass(new THREE.Vector2(window.innerWidth, window.innerHeight), 1.5, 0.4, 0);
        bloomPass.strength = 1.5; bloomPass.radius = 0.4; bloomPass.threshold = 0;
        const composer = new THREE.EffectComposer(renderer);
        composer.addPass(renderScene);
        composer.addPass(bloomPass);

        const dummy = new THREE.Object3D();
        const color = new THREE.Color();
        const target = new THREE.Vector3();
        const geometry = new THREE.SphereGeometry(0.25, 8, 8);
        const material = new THREE.MeshBasicMaterial({ color: 0xffffff });
        const instancedMesh = new THREE.InstancedMesh(geometry, material, COUNT);
        instancedMesh.instanceMatrix.setUsage(THREE.DynamicDrawUsage);
        scene.add(instancedMesh);

        const positions = [];
        for (let i = 0; i < COUNT; i++) {
            positions.push(new THREE.Vector3(
                (Math.random() - 0.5) * 50,
                (Math.random() - 0.5) * 50,
                (Math.random() - 0.5) * 50
            ));
        }

        const radiusSlider = document.getElementById('radius');
        const heightSlider = document.getElementById('height');
        const twistSlider = document.getElementById('twist');
        radiusSlider.addEventListener('input', (e) => document.getElementById('radVal').textContent = e.target.value);
        heightSlider.addEventListener('input', (e) => document.getElementById('htVal').textContent = e.target.value);
        twistSlider.addEventListener('input', (e) => document.getElementById('twistVal').textContent = e.target.value);

        document.getElementById('count').textContent = COUNT;
        let lastTime = performance.now(), frameCount = 0;
        const fpsEl = document.getElementById('fps');
        const clock = new THREE.Clock();

        function animate() {
            requestAnimationFrame(animate);
            const now = performance.now();
            frameCount++;
            if (now - lastTime >= 1000) { fpsEl.textContent = frameCount; frameCount = 0; lastTime = now; }

            const time = clock.getElapsedTime();
            const r = parseFloat(radiusSlider.value);
            const h = parseFloat(heightSlider.value);
            const twists = parseFloat(twistSlider.value);
            const countPerStrand = COUNT / 2;

            for (let i = 0; i < COUNT; i++) {
                const isFirstStrand = i < countPerStrand;
                const idx = isFirstStrand ? i : i - countPerStrand;
                const t = idx / countPerStrand; // 0 to 1
                
                const angle = t * Math.PI * 2 * twists + time * 0.5;
                const y = (t - 0.5) * h;
                
                // 双螺旋相位差 180度
                const phaseOffset = isFirstStrand ? 0 : Math.PI;
                const currentAngle = angle + phaseOffset;
                
                // 添加连接桥的动画偏移
                const bridgeOffset = Math.sin(t * Math.PI * twists * 2 + time) * 0.5;
                
                target.set(
                    Math.cos(currentAngle) * (r + bridgeOffset),
                    y,
                    Math.sin(currentAngle) * (r + bridgeOffset)
                );
                
                positions[i].lerp(target, 0.1);
                dummy.position.copy(positions[i]);
                dummy.lookAt(0, y, 0);
                dummy.updateMatrix();
                instancedMesh.setMatrixAt(i, dummy.matrix);
                
                // 颜色：双链不同色 + 渐变
                const hue = isFirstStrand ? 0.55 : 0.15; // 蓝 vs 橙
                const lightness = 0.5 + Math.sin(t * Math.PI * 10 + time * 2) * 0.2;
                color.setHSL(hue, 0.9, lightness);
                instancedMesh.setColorAt(i, color);
            }

            instancedMesh.instanceMatrix.needsUpdate = true;
            instancedMesh.instanceColor.needsUpdate = true;
            controls.update();
            composer.render();
        }
        animate();

        window.addEventListener('resize', () => {
            camera.aspect = window.innerWidth / window.innerHeight;
            camera.updateProjectionMatrix();
            renderer.setSize(window.innerWidth, window.innerHeight);
            composer.setSize(window.innerWidth, window.innerHeight);
        });
    </script>
</body>
</html>