How Many Tokens Do 3D Point Cloud Transformer Architectures Really Need?

Mathias Niepert (Universität Stuttgart & NEC Labs Europe) · Roger Wattenhofer (ETH Zurich) · Tuan Tran Anh (German Research Center for AI) · Duy M. H. Nguyen (DFKI) · Hoai-Chau Tran (University of Illinois at Urbana-Champaign) · Michael Barz (German Research Center for Artificial Intelligence, DFKI) · Khoa D Doan (VinUniversity) · Vien Ngo (Bosch Center for Artificial Intelligence) · Daniel Sonntag (German Research Center for AI) · Paul Swoboda (Heinrich-Heine University Düsseldorf)
3d point cloud transformers3d vision taskscompetitive performancecomputational efficiencyfoundation modelsinference costslarge-scale modelsover-tokenizationredundancy assessmentscalable architecturessemantic segmentationtoken merging methodtoken representationstraining efficiencyunder-optimization

Recent advances in 3D point cloud transformers have led to state-of-the-art results in tasks such as semantic segmentation and reconstruction. However, these models typically rely on dense token representations, incurring high computational and memory costs during training and inference. In this work, we present the finding that tokens are remarkably redundant, leading to substantial inefficiency. We introduce an efficient token merging method and illustrate that it can reduce the token count by up to 90–95% while maintaining competitive performance. This finding challenges the prevailing assumption that more tokens inherently yield better performance and highlights that many current models are over-tokenized and under-optimized for scalability. We validate our method across multiple 3D vision tasks and show consistent improvements in computational efficiency. This work is the first to assess redundancy in large-scale 3D transformer models, providing insights into the development of more efficient 3D foundation architectures. Our code and checkpoints are publicly available at https://gitmerge3d.github.io.