PartDistill: 3D Shape Part Segmentation by Vision-Language Model Distillation
Authors: Ardian Umam, Cheng-Kun Yang, Min-Hung Chen, Jen-Hui Chuang, Yen-Yu Lin

This paper proposes a cross-modal distillation framework PartDistill which transfers 2D knowledge from vision-language models (VLMs) to facilitate 3D shape part segmentation. PartDistill addresses three major challenges in this task: the lack of 3D segmentation in invisible or undetected regions in the 2D projections inconsistent 2D predictions by VLMs and the lack of knowledge accumulation across different 3D shapes. PartDistill consists of a teacher network that uses a VLM to make 2D predictions and a student network that learns from the 2D predictions while extracting geometrical features from multiple 3D shapes to carry out 3D part segmentation. A bi-directional distillation including forward and backward distillations is carried out within the framework where the former forward distills the 2D predictions to the student network and the latter improves the quality of the 2D predictions which subsequently enhances the final 3D segmentation. Moreover PartDistill can exploit generative models that facilitate effortless 3D shape creation for generating knowledge sources to be distilled. Through extensive experiments PartDistill boosts the existing methods with substantial margins on widely used ShapeNetPart and PartNetE datasets by more than 15% and 12% higher mIoU scores respectively. The code for this work is available at https://github.com/ardianumam/PartDistill.