Vision-Only Gaussian Splatting for Collaborative Semantic Occupancy Prediction
This addresses the problem of high communication costs and depth estimation requirements in collaborative perception for autonomous vehicles, representing a novel method rather than an incremental improvement.
The paper tackles collaborative 3D semantic occupancy prediction for connected vehicles by proposing a vision-only method using sparse 3D semantic Gaussian splatting, which outperforms single-agent perception by +8.42 points in mIoU and baseline collaborative methods by +3.28 points in mIoU while reducing communication volume to 34.6%.
Collaborative perception enables connected vehicles to share information, overcoming occlusions and extending the limited sensing range inherent in single-agent (non-collaborative) systems. Existing vision-only methods for 3D semantic occupancy prediction commonly rely on dense 3D voxels, which incur high communication costs, or 2D planar features, which require accurate depth estimation or additional supervision, limiting their applicability to collaborative scenarios. To address these challenges, we propose the first approach leveraging sparse 3D semantic Gaussian splatting for collaborative 3D semantic occupancy prediction. By sharing and fusing intermediate Gaussian primitives, our method provides three benefits: a neighborhood-based cross-agent fusion that removes duplicates and suppresses noisy or inconsistent Gaussians; a joint encoding of geometry and semantics in each primitive, which reduces reliance on depth supervision and allows simple rigid alignment; and sparse, object-centric messages that preserve structural information while reducing communication volume. Extensive experiments demonstrate that our approach outperforms single-agent perception and baseline collaborative methods by +8.42 and +3.28 points in mIoU, and +5.11 and +22.41 points in IoU, respectively. When further reducing the number of transmitted Gaussians, our method still achieves a +1.9 improvement in mIoU, using only 34.6% communication volume, highlighting robust performance under limited communication budgets.