  This technical report introduces our solutions of Team 'FineGrainedSeg' for
Instance Segmentation track in 3D AI Challenge 2020. In order to handle
extremely large objects in 3D-FUTURE, we adopt PointRend as our basic
framework, which outputs more fine-grained masks compared to HTC and SOLOv2.
Our final submission is an ensemble of 5 PointRend models, which achieves the
1st place on both validation and test leaderboards. The code is available at
https://github.com/zehuichen123/3DFuture_ins_seg.
