R3D2: Realistic 3D Asset Insertion via Diffusion for Autonomous Driving Simulation

William Ljungbergh; Bernardo Taveira; Wenzhao Zheng; Adam Tonderski; Chensheng Peng; Fredrik Kahl; Christoffer Petersson; Michael Felsberg; Kurt Keutzer; Masayoshi Tomizuka; Wei Zhan

arXiv · 2506.07826

R3D2: Realistic 3D Asset Insertion via Diffusion for Autonomous Driving Simulation

William Ljungbergh·Bernardo Taveira·Wenzhao Zheng·Adam Tonderski·Chensheng Peng·Fredrik Kahl·Christoffer Petersson·Michael Felsberg·Kurt Keutzer·Masayoshi Tomizuka·Wei Zhan

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Abstract

Validating autonomous driving (AD) systems requires diverse and safety-critical testing, making photorealistic virtual environments essential. Traditional simulation platforms, while controllable, are resource-intensive to scale and often suffer from a domain gap with real-world data. In contrast, neural reconstruction methods like 3D Gaussian Splatting (3DGS) offer a scalable solution for creating photorealistic digital twins of real-world driving scenes. However, they struggle with dynamic object manipulation and reusability as their per-scene optimization-based methodology tends to result in incomplete object models with integrated illumination effects. This paper introduces R3D2, a lightweight, one-step diffusion model designed to overcome these limitations and enable realistic insertion of complete 3D assets into existing scenes by generating plausible rendering effects-such as shadows and consistent lighting-in real time. This is achieved by training R3D2 on a novel dataset: 3DGS object assets are generated from in-the-wild AD data using an image-conditioned 3D generative model, and then synthetically placed into neural rendering-based virtual environments, allowing R3D2 to learn realistic integration. Quantitative and qualitative evaluations demonstrate that R3D2 significantly enhances the realism of inserted assets, enabling use-cases like text-to-3D asset insertion and cross-scene/dataset object transfer, allowing for true scalability in AD validation. To promote further research in scalable and realistic AD simulation, we release our code, see https://research.zenseact.com/publications/R3D2/.

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William Ljungbergh, Bernardo Taveira, Wenzhao Zheng, Adam Tonderski, Chensheng Peng, Fredrik Kahl, Christoffer Petersson, Michael Felsberg, Kurt Keutzer, Masayoshi Tomizuka, Wei Zhan. 2026-04-19. R3D2: Realistic 3D Asset Insertion via Diffusion for Autonomous Driving Simulation. https://arxiv.org/abs/2506.07826

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