MASC: Multi-scale Affinity with Sparse Convolution for 3D Instance Segmentation

12 Feb 2019  ·  Chen Liu, Yasutaka Furukawa ·

We propose a new approach for 3D instance segmentation based on sparse convolution and point affinity prediction, which indicates the likelihood of two points belonging to the same instance. The proposed network, built upon submanifold sparse convolution [3], processes a voxelized point cloud and predicts semantic scores for each occupied voxel as well as the affinity between neighboring voxels at different scales. A simple yet effective clustering algorithm segments points into instances based on the predicted affinity and the mesh topology. The semantic for each instance is determined by the semantic prediction. Experiments show that our method outperforms the state-of-the-art instance segmentation methods by a large margin on the widely used ScanNet benchmark [2]. We share our code publicly at

PDF Abstract


Results from the Paper

Task Dataset Model Metric Name Metric Value Global Rank Result Benchmark
3D Instance Segmentation ScanNet MASC mAP 0.447 # 1
3D Instance Segmentation ScanNet(v2) ResNet-Backbone mAP @ 50 45.9 # 17
3D Instance Segmentation ScanNet(v2) MASC mAP 25.4 # 15
mAP @ 50 44.7 # 18