aurora-animations/ai-fluid-simulation-202603250302.html at master · robertsong2000/aurora-animations · GitHub

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<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>流体模拟 - Fluid Simulation</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            overflow: hidden;
            background: #000;
            font-family: 'Arial', sans-serif;
        }

        canvas {
            display: block;
            position: absolute;
            top: 0;
            left: 0;
        }

        .info {
            position: fixed;
            bottom: 20px;
            left: 20px;
            color: rgba(100, 200, 255, 0.8);
            font-size: 14px;
            z-index: 100;
            pointer-events: none;
            text-shadow: 0 0 15px rgba(100, 200, 255, 0.6);
        }

        .title {
            position: fixed;
            top: 30px;
            left: 50%;
            transform: translateX(-50%);
            color: rgba(100, 200, 255, 0.9);
            font-size: 32px;
            font-weight: bold;
            z-index: 100;
            text-shadow: 0 0 30px rgba(100, 200, 255, 0.8);
            letter-spacing: 5px;
        }

        .fps {
            position: fixed;
            top: 20px;
            right: 20px;
            color: rgba(100, 200, 255, 0.6);
            font-size: 12px;
            font-family: monospace;
            z-index: 100;
        }

        @media (max-width: 768px) {
            .info {
                font-size: 11px;
                bottom: 10px;
                left: 10px;
            }
            .title {
                font-size: 20px;
                top: 15px;
            }
        }
    </style>
</head>
<body>
    <div class="title">🌊 流体模拟</div>
    <canvas id="fluid"></canvas>
    <div class="info">
        <div>🖱️ 拖动鼠标 - 产生流动</div>
        <div>👆 点击 - 产生涟漪</div>
    </div>
    <div class="fps" id="fps">FPS: 60</div>

    <script>
        // 性能监控
        const fpsElement = document.getElementById('fps');
        let lastTime = performance.now();
        let frameCount = 0;

        // Canvas 设置
        const canvas = document.getElementById('fluid');
        const ctx = canvas.getContext('2d');

        let width, height;
        let mouseX = 0, mouseY = 0;
        let isMouseDown = false;

        // 流体网格
        const GRID_SCALE = 5;
        let gridWidth, gridHeight;
        let density, densityPrev;
        let velocityX, velocityY, velocityXPrev, velocityYPrev;

        // 参数
        const DIFFUSION = 0.0001;
        const VISCOSITY = 0.0000001;
        const DT = 0.1;
        const ITERATIONS = 4;

        // 颜色配置
        const COLORS = {
            low: { r: 0, g: 50, b: 100 },
            high: { r: 100, g: 200, b: 255 },
        };

        // 响应式调整
        function resize() {
            width = canvas.width = window.innerWidth;
            height = canvas.height = window.innerHeight;
            initFluid();
        }

        // 初始化流体
        function initFluid() {
            gridWidth = Math.ceil(width / GRID_SCALE);
            gridHeight = Math.ceil(height / GRID_SCALE);

            const size = gridWidth * gridHeight;

            density = new Float32Array(size);
            densityPrev = new Float32Array(size);
            velocityX = new Float32Array(size);
            velocityY = new Float32Array(size);
            velocityXPrev = new Float32Array(size);
            velocityYPrev = new Float32Array(size);
        }

        // 获取网格索引
        function IX(x, y) {
            x = Math.max(0, Math.min(gridWidth - 1, x));
            y = Math.max(0, Math.min(gridHeight - 1, y));
            return x + y * gridWidth;
        }

        // 设置边界条件
        function setBnd(b, x) {
            for (let i = 1; i < gridWidth - 1; i++) {
                x[IX(i, 0)] = b === 2 ? -x[IX(i, 1)] : x[IX(i, 1)];
                x[IX(i, gridHeight - 1)] = b === 2 ? -x[IX(i, gridHeight - 2)] : x[IX(i, gridHeight - 2)];
            }

            for (let j = 1; j < gridHeight - 1; j++) {
                x[IX(0, j)] = b === 1 ? -x[IX(1, j)] : x[IX(1, j)];
                x[IX(gridWidth - 1, j)] = b === 1 ? -x[IX(gridWidth - 2, j)] : x[IX(gridWidth - 2, j)];
            }

            x[IX(0, 0)] = 0.5 * (x[IX(1, 0)] + x[IX(0, 1)]);
            x[IX(0, gridHeight - 1)] = 0.5 * (x[IX(1, gridHeight - 1)] + x[IX(0, gridHeight - 2)]);
            x[IX(gridWidth - 1, 0)] = 0.5 * (x[IX(gridWidth - 2, 0)] + x[IX(gridWidth - 1, 1)]);
            x[IX(gridWidth - 1, gridHeight - 1)] = 0.5 * (x[IX(gridWidth - 2, gridHeight - 1)] + x[IX(gridWidth - 1, gridHeight - 2)]);
        }

        // 扩散
        function diffuse(b, x, x0, diff) {
            const a = DT * diff * (gridWidth - 2) * (gridHeight - 2);
            linearSolve(b, x, x0, a, 1 + 6 * a);
        }

        // 线性求解
        function linearSolve(b, x, x0, a, c) {
            const cRecip = 1.0 / c;

            for (let k = 0; k < ITERATIONS; k++) {
                for (let j = 1; j < gridHeight - 1; j++) {
                    for (let i = 1; i < gridWidth - 1; i++) {
                        x[IX(i, j)] = (x0[IX(i, j)] + a * (
                            x[IX(i + 1, j)] + x[IX(i - 1, j)] +
                            x[IX(i, j + 1)] + x[IX(i, j - 1)]
                        )) * cRecip;
                    }
                }
                setBnd(b, x);
            }
        }

        // 平流
        function advect(b, d, d0, velocX, velocY) {
            let i0, i1, j0, j1;

            const dtx = DT * (gridWidth - 2);
            const dty = DT * (gridHeight - 2);

            let s0, s1, t0, t1;
            let tmp1, tmp2, x, y;

            for (let j = 1; j < gridHeight - 1; j++) {
                for (let i = 1; i < gridWidth - 1; i++) {
                    tmp1 = dtx * velocX[IX(i, j)];
                    tmp2 = dty * velocY[IX(i, j)];

                    x = i - tmp1;
                    y = j - tmp2;

                    if (x < 0.5) x = 0.5;
                    if (x > gridWidth + 0.5) x = gridWidth + 0.5;
                    i0 = Math.floor(x);
                    i1 = i0 + 1;

                    if (y < 0.5) y = 0.5;
                    if (y > gridHeight + 0.5) y = gridHeight + 0.5;
                    j0 = Math.floor(y);
                    j1 = j0 + 1;

                    s1 = x - i0;
                    s0 = 1 - s1;
                    t1 = y - j0;
                    t0 = 1 - t1;

                    const i0i = Math.floor(i0);
                    const i1i = Math.floor(i1);
                    const j0i = Math.floor(j0);
                    const j1i = Math.floor(j1);

                    d[IX(i, j)] =
                        s0 * (t0 * d0[IX(i0i, j0i)] + t1 * d0[IX(i0i, j1i)]) +
                        s1 * (t0 * d0[IX(i1i, j0i)] + t1 * d0[IX(i1i, j1i)]);
                }
            }
            setBnd(b, d);
        }

        // 投影
        function project(velocX, velocY, p, div) {
            for (let j = 1; j < gridHeight - 1; j++) {
                for (let i = 1; i < gridWidth - 1; i++) {
                    div[IX(i, j)] = -0.5 * (
                        velocX[IX(i + 1, j)] - velocX[IX(i - 1, j)] +
                        velocY[IX(i, j + 1)] - velocY[IX(i, j - 1)]
                    ) / gridWidth;
                    p[IX(i, j)] = 0;
                }
            }

            setBnd(0, div);
            setBnd(0, p);
            linearSolve(0, p, div, 1, 6);

            for (let j = 1; j < gridHeight - 1; j++) {
                for (let i = 1; i < gridWidth - 1; i++) {
                    velocX[IX(i, j)] -= 0.5 * (p[IX(i + 1, j)] - p[IX(i - 1, j)]) * gridWidth;
                    velocY[IX(i, j)] -= 0.5 * (p[IX(i, j + 1)] - p[IX(i, j - 1)]) * gridHeight;
                }
            }

            setBnd(1, velocX);
            setBnd(2, velocY);
        }

        // 更新流体
        function updateFluid() {
            // 扩散速度
            diffuse(1, velocityXPrev, velocityX, VISCOSITY);
            diffuse(2, velocityYPrev, velocityY, VISCOSITY);

            // 投影
            project(velocityXPrev, velocityYPrev, velocityX, velocityY);

            // 平流速度
            advect(1, velocityX, velocityXPrev, velocityXPrev, velocityYPrev);
            advect(2, velocityY, velocityYPrev, velocityXPrev, velocityYPrev);

            // 投影
            project(velocityX, velocityY, velocityXPrev, velocityYPrev);

            // 扩散密度
            diffuse(0, densityPrev, density, DIFFUSION);

            // 平流密度
            advect(0, density, densityPrev, velocityX, velocityY);

            // 衰减
            for (let i = 0; i < density.length; i++) {
                density[i] *= 0.99;
            }
        }

        // 添加密度和速度
        function addDensity(x, y, amount) {
            const gridX = Math.floor(x / GRID_SCALE);
            const gridY = Math.floor(y / GRID_SCALE);
            density[IX(gridX, gridY)] += amount;
        }

        function addVelocity(x, y, amountX, amountY) {
            const gridX = Math.floor(x / GRID_SCALE);
            const gridY = Math.floor(y / GRID_SCALE);
            velocityX[IX(gridX, gridY)] += amountX;
            velocityY[IX(gridX, gridY)] += amountY;
        }

        // 绘制流体
        function drawFluid() {
            const imageData = ctx.createImageData(width, height);

            for (let j = 0; j < gridHeight; j++) {
                for (let i = 0; i < gridWidth; i++) {
                    const d = density[IX(i, j)];

                    const r = COLORS.low.r + (COLORS.high.r - COLORS.low.r) * d;
                    const g = COLORS.low.g + (COLORS.high.g - COLORS.low.g) * d;
                    const b = COLORS.low.b + (COLORS.high.b - COLORS.low.b) * d;

                    // 填充网格区域
                    for (let py = 0; py < GRID_SCALE; py++) {
                        for (let px = 0; px < GRID_SCALE; px++) {
                            const pixelX = i * GRID_SCALE + px;
                            const pixelY = j * GRID_SCALE + py;

                            if (pixelX < width && pixelY < height) {
                                const idx = (pixelY * width + pixelX) * 4;
                                imageData.data[idx] = r;
                                imageData.data[idx + 1] = g;
                                imageData.data[idx + 2] = b;
                                imageData.data[idx + 3] = 255;
                            }
                        }
                    }
                }
            }

            ctx.putImageData(imageData, 0, 0);
        }

        // 主动画循环
        function animate(currentTime) {
            // 更新流体
            updateFluid();

            // 绘制流体
            drawFluid();

            // FPS 计算
            frameCount++;
            if (frameCount >= 30) {
                const fps = Math.round(30 / ((currentTime - lastTime) / 1000 * 30));
                fpsElement.textContent = `FPS: ${Math.min(fps, 60)}`;
                frameCount = 0;
            }

            lastTime = currentTime;
            requestAnimationFrame(animate);
        }

        // 事件监听
        window.addEventListener('resize', resize);

        canvas.addEventListener('mousemove', (e) => {
            const prevMouseX = mouseX;
            const prevMouseY = mouseY;
            mouseX = e.clientX;
            mouseY = e.clientY;

            if (isMouseDown) {
                const dx = mouseX - prevMouseX;
                const dy = mouseY - prevMouseY;

                addDensity(mouseX, mouseY, 10);
                addVelocity(mouseX, mouseY, dx * 5, dy * 5);
            }
        });

        canvas.addEventListener('mousedown', () => {
            isMouseDown = true;
        });

        canvas.addEventListener('mouseup', () => {
            isMouseDown = false;
        });

        canvas.addEventListener('click', (e) => {
            // 产生涟漪
            for (let i = -2; i <= 2; i++) {
                for (let j = -2; j <= 2; j++) {
                    addDensity(e.clientX + i * 10, e.clientY + j * 10, 50);
                    addVelocity(e.clientX + i * 10, e.clientY + j * 10, i * 20, j * 20);
                }
            }
        });

        canvas.addEventListener('touchmove', (e) => {
            e.preventDefault();
            const touch = e.touches[0];
            const dx = touch.clientX - mouseX;
            const dy = touch.clientY - mouseY;
            mouseX = touch.clientX;
            mouseY = touch.clientY;

            addDensity(mouseX, mouseY, 10);
            addVelocity(mouseX, mouseY, dx * 5, dy * 5);
        });

        canvas.addEventListener('touchstart', (e) => {
            e.preventDefault();
            const touch = e.touches[0];
            mouseX = touch.clientX;
            mouseY = touch.clientY;

            // 产生涟漪
            for (let i = -2; i <= 2; i++) {
                for (let j = -2; j <= 2; j++) {
                    addDensity(mouseX + i * 10, mouseY + j * 10, 50);
                    addVelocity(mouseX + i * 10, mouseY + j * 10, i * 20, j * 20);
                }
            }
        });

        // 初始化
        resize();
        mouseX = width / 2;
        mouseY = height / 2;
        requestAnimationFrame(animate);
    </script>
</body>
</html>