We present MultiNeRF, a novel 3D watermarking method that enables embedding multiple uniquely keyed watermarks within images rendered by a single Neural Radiance Field (NeRF) model while maintaining high visual quality. Our approach extends TensoRF by incorporating a dedicated watermark grid alongside geometry and appearance grids, ensuring higher watermark capacity without entanglement with scene content. We propose a FiLM-based conditional modulation mechanism that dynamically activates watermarks based on input identifiers, allowing multiple independent watermarks to be embedded and extracted without retraining. Experiments on NeRF-Synthetic and LLFF demonstrate improved robustness and watermark capacity while preserving rendering quality. MultiNeRF generalizes prior single-watermark methods, providing a scalable solution for securing ownership and attribution in 3D content.
@inproceedings{Kulthe:MultiNeRF:ICCVWS:2025,
author = {Yash Kulthe and Andrew Gilbert and John Collomosse},
title = {MultiNeRF: Multiple Watermark Embedding for Neural Radiance Fields},
booktitle = {International Conference on Computer Vision (ICCV'25) - The 1st Workshop on Authenticity & Provenance in the age of Generative AI (APAI'25)},
year = {2025}
}