We consider the problem of synthesizing photorealistic, physically plausible combustion effects in in-the-wild 3D scenes. Traditional CFD and graphics pipelines can produce realistic fire effects but rely on handcrafted geometry, expert-tuned parameters, and labor-intensive workflows, limiting their scalability to the real world. Recent scene modeling advances like 3D Gaussian Splatting (3DGS) enable high-fidelity real-world scene reconstruction, yet lack physical grounding for combustion. To bridge this gap, we propose FieryGS, a physically-based framework that integrates physically-accurate and user-controllable combustion simulation and rendering within the 3DGS pipeline, enabling realistic fire synthesis for real scenes. Our approach tightly couples three key modules: (1) multimodal large-language-model-based physical material reasoning, (2) efficient volumetric combustion simulation, and (3) a unified renderer for fire and 3DGS. By unifying reconstruction, physical reasoning, simulation, and rendering, FieryGS removes manual tuning and automatically generates realistic, controllable fire dynamics consistent with scene geometry and materials. Our framework supports complex combustion phenomena -- including flame propagation, smoke dispersion, and surface carbonization -- with precise user control over fire intensity, airflow, ignition location and other combustion parameters. Evaluated on diverse indoor and outdoor scenes, FieryGS outperforms all comparative baselines in visual realism, physical fidelity, and controllability. Project page can be found at https://pku-vcl-geometry.github.io/FieryGS/.

翻译：我们研究在野外三维场景中合成具有照片级真实感且物理合理的燃烧效果问题。传统计算流体力学与图形学管线能生成逼真的火焰效果，但依赖手工几何建模、专家调参及繁琐工作流，限制了其在真实世界中的可扩展性。近年来三维高斯泼溅（3DGS）等场景建模技术可实现对真实场景的高保真重建，但缺乏燃烧过程的物理支撑。为弥合这一鸿沟，我们提出FieryGS——一个基于物理的框架，将物理精确且用户可控的燃烧模拟与渲染集成至3DGS管线中，实现对真实场景的逼真火焰合成。该方法紧密耦合三大核心模块：（1）基于多模态大语言模型的物理材质推理，（2）高效体积燃烧模拟，以及（3）火焰与3DGS统一渲染器。通过统一重建、物理推理、模拟与渲染流程，FieryGS消除了人工调参步骤，自动生成与场景几何及材质一致的、真实且可控的火焰动态。该框架支持复杂燃烧现象——包括火焰传播、烟尘扩散与表面碳化——并允许用户精确控制火焰强度、气流、点火位置等燃烧参数。在多样化室内外场景上的评估表明，FieryGS在视觉真实感、物理保真度与可控性方面均超越所有对比基线。项目页面见 https://pku-vcl-geometry.github.io/FieryGS/。