iCVTEAM.github.io/ChronosObserver.html at master · iCVTEAM/iCVTEAM.github.io · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>ChronosObserver - Project Page</title>
    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;800&display=swap" rel="stylesheet">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css">
    <link rel="icon" href="./assets/ChronosObserver/images/icon.png">

    <style>
        :root {
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            --card-bg: #ffffff;
            --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -2px rgb(0 0 0 / 0.05);
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        body {
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        .hero-logo {
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        h1 {
            font-size: 2.5rem;
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    </style>
</head>
<body>

<nav>
    <a href="#abstract">Abstract</a>
    <a href="#results">Results</a>
    <a href="#citation">Citation</a>
</nav>

<div class="container">

    <div class="hero">
        <div class="hero-title-group">
            <img src="./assets/ChronosObserver/images/logo.png" alt="Logo" class="hero-logo">
            <h1>Taming 4D World with Hyperspace Diffusion Sampling</h1>
        </div>
        <p style="text-align: center; color: #64748b; font-size: 1.25rem; margin-top: 15px;">
            A training-free method for temporal-synchronized multi-view video generation
        </p>

        <div class="authors">
            <a href="#">Qisen Wang</a>,
            <a href="#">Yifan Zhao</a>,
            <a href="#">Peisen Shen</a>,
            <a href="#">Jialu Li</a>,
            <a href="#">Jia Li</a>
        </div>
        <div class="affiliation">Beihang University</div>

        <div class="btn-group">
            <a href="https://arxiv.org/abs/2512.01481" class="btn"><i class="fas fa-file-pdf"></i> Paper</a>
            <a href="https://github.com/iCVTEAM/ChronosObserver" class="btn btn-outline"><i class="fab fa-github"></i> Code</a>
        </div>
    </div>

    <div class="card" style="padding: 0; overflow: hidden;">
        <video autoplay muted loop playsinline controls style="width: 80%; max-width: 1280px; display: block; margin: 0 auto;">
            <source src="./assets/ChronosObserver/videos/ChronosObserver/video.mp4" type="video/mp4">
            Your browser does not support the video tag.
        </video>
    </div>

    <div class="card" id="abstract">
        <h2 class="section-title">Abstract</h2>
        <p>
            Although prevailing camera-controlled video generation models can produce cinematic results, lifting them directly to the generation of 3D-consistent and high-fidelity time-synchronized multi-view videos remains challenging, which is a pivotal capability for taming 4D worlds. Some works resort to data augmentation or test-time optimization, but these strategies are constrained by limited model generalization and scalability issues. To this end, we propose ChronosObserver, a training-free method including World State Hyperspace to represent the spatiotemporal constraints of a 4D world scene, and Hyperspace Guided Sampling to synchronize the diffusion sampling trajectories of multiple views using the hyperspace. Experimental results demonstrate that our method achieves high-fidelity and 3D-consistent time-synchronized multi-view videos generation without training or fine-tuning for diffusion models.
        </p>
    </div>

    <div class="card" id="results">
        <h2 class="section-title">Comparison Results</h2>

        <h3 class="title is-3">Qualitative Comparisons</h3>
        <video autoplay muted loop playsinline style="width: 90%; max-width: 1280px; display: block; margin: 0 auto;">
            <source src="./assets/ChronosObserver/videos/comp_others/example1.mp4" type="video/mp4">
        </video>
        <video autoplay muted loop playsinline style="width: 90%; max-width: 1280px; display: block; margin: 0 auto;">
            <source src="./assets/ChronosObserver/videos/comp_others/example2.mp4" type="video/mp4">
        </video>

        <h3 class="title is-3">Ablations</h3>

        <div class="ablation-grid">

            <div class="comparison-slider">
                <div class="video-layer">
                    <video class="video-bg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example1/abla_1_ours_wo_ISH.mp4" type="video/mp4">
                    </video>
                    <div class="label label-right">w/o I.S.H.</div>
                </div>
                <div class="video-layer video-overlay">
                    <video class="video-fg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example1/abla_1_ours.mp4" type="video/mp4">
                    </video>
                    <div class="label label-left">Ours</div>
                </div>
                <div class="slider-handle"><div class="handle-circle"><i class="fas fa-arrows-alt-h"></i></div></div>
            </div>

            <div class="comparison-slider">
                <div class="video-layer">
                    <video class="video-bg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example2/abla_2_ours_wo_HGS.mp4" type="video/mp4">
                    </video>
                    <div class="label label-right">w/o H.G.S.</div>
                </div>
                <div class="video-layer video-overlay">
                    <video class="video-fg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example2/abla_2_ours.mp4" type="video/mp4">
                    </video>
                    <div class="label label-left">Ours</div>
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                <div class="slider-handle"><div class="handle-circle"><i class="fas fa-arrows-alt-h"></i></div></div>
            </div>

            <div class="comparison-slider">
                <div class="video-layer">
                    <video class="video-bg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example3/abla_3_ours_wo_ISH_wo_HGS.mp4" type="video/mp4">
                    </video>
                    <div class="label label-right">w/o I.S.H. w/o H.G.S.</div>
                </div>
                <div class="video-layer video-overlay">
                    <video class="video-fg" autoplay muted loop playsinline>
                        <source src="./assets/ChronosObserver/ablation/example3/abla_3_ours.mp4" type="video/mp4">
                    </video>
                    <div class="label label-left">Ours</div>
                </div>
                <div class="slider-handle"><div class="handle-circle"><i class="fas fa-arrows-alt-h"></i></div></div>
            </div>

        </div>

        <h3 class="title is-3">More Visualization Results</h3>
        <video autoplay muted loop playsinline style="width: 90%; max-width: 1280px; display: block; margin: 0 auto;"><source src="./assets/ChronosObserver/videos/ours/example1.mp4" type="video/mp4"></video>
        <video autoplay muted loop playsinline style="width: 90%; max-width: 1280px; display: block; margin: 0 auto;"><source src="./assets/ChronosObserver/videos/ours/example2.mp4" type="video/mp4"></video>
        <video autoplay muted loop playsinline style="width: 90%; max-width: 1280px; display: block; margin: 0 auto;"><source src="./assets/ChronosObserver/videos/ours/example3.mp4" type="video/mp4"></video>
    </div>

    <div class="card" id="citation" style="max-width: 800px; margin: 0 auto 40px auto;">
        <h2 class="section-title">Citation</h2>
        <pre><code>@article{wang2025chronosobserver,
  title={ChronosObserver: Taming 4D World with Hyperspace Diffusion Sampling},
  author={Wang, Qisen and Zhao, Yifan and Shen, Peisen and Li, Jialu and Li, Jia},
  journal={arXiv preprint arXiv:2512.01481},
  year={2025}
}</code></pre>
    </div>

</div>

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</body>
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