InsideOut: Integrated RGB-Radiative Gaussian Splatting for ComprehSensive 3D Object Representation

Jungmin Lee1, Seonghyuk Hong2, Juyong Lee1, Jaeyoon Lee1, Jongwon Choi*1, 2
1VILab, Chung-Ang University, Republic of Korea 2Cultural Heritage Conservation Science Center, National Research Institute of Cultural Heritage, Republic of Korea
Paper Data (soon) Video (soon) Code (soon)

What if 3D objects could show both surface details and hidden interior simultaneously?
We explore two distinct imaging modalities that capture complementary aspects of the world: RGB imaging reveals rich surface textures and colors, while X-ray imaging penetrates through materials to expose internal structures. These modalities are naturally complementary but have never been unified in 3D reconstruction. InsideOut, bridges gap by extending 3D Gaussian Splatting to fuse RGB and X-ray data, enabling unprecedented visualization capabilities for medical diagnostics, cultural heritage analysis, and manufacturing inspection.

Abstract

We introduce InsideOut, an extension of 3D Gaussian splatting (3DGS) that bridges the gap between high-fidelity RGB surface details and subsurface X-ray structures. The fusion of RGB and X-ray imaging is invaluable in fields such as medical diagnostics, cultural heritage restoration, and manufacturing. We collect new paired RGB and X-ray data, perform hierarchical fitting to align RGB and X-ray radiative Gaussian splats, and propose an X-ray reference loss to ensure consistent internal structures. InsideOut effectively addresses the challenges posed by disparate data representations between the two modalities and limited paired datasets. This approach significantly extends the applicability of 3DGS, enhancing visualization, simulation, and non-destructive testing capabilities across various domains.

Framework

Results

Internal Rendering

InsideOut achieves internal detail preservation while mitigating noise, thereby improving overall rendering fidelity.

Mesh Reconstruction

InsideOut captures diverse normal distributions.


Application

InsideOut visualizes external appearance and internal structures, enabling analysis and physical simulation.


Real-world Asset Diagnosis

Interactive Asset


BibTeX

@InProceedings{,
        author    = {},
        title     = {InsideOut: Integrated RGB-Radiative Gaussian Splatting for ComprehSensive 3D Object Representation},
        booktitle = {Proceedings of the IEEE/CVF International Conference on Computer Vision (ICCV)},
        month     = {October},
        year      = {2025},
        pages     = {}
    }