Pred-NBV: Prediction-guided Next-Best-View for 3D Object Reconstruction

University of Maryland, College Park
*Equal contribution (listed alphabatically)
Interpolation end reference image.

Abstract

Prediction-based active perception has shown the potential to improve the navigation efficiency and safety of the robot by anticipating the uncertainty in the unknown environment. The existing works for 3D shape prediction make an implicit assumption about the partial observations and therefore cannot be used for real-world planning and do not consider the control effort for next-best-view planning. We present Pred-NBV, a realistic object shape reconstruction method consisting of PoinTr-C, an enhanced 3D prediction model trained on the ShapeNet dataset, and an information and control effort-based next-best-view method to address these issues. Pred-NBV shows an improvement of 25.46% in object coverage over the traditional method in the AirSim simulator, and performs better shape completion than PoinTr, the state- of-the-art shape completion model, even on real data obtained from a Velodyne 3D LiDAR mounted on DJI M600 Pro.


Video

Our method predicts the point cloud based on partial observations and helps the robot find an efficient path to observed the object.


Prediction on Real-World Data

Here we compare PoinTr, a 3D shape completion, against PoinTr-C, a improved version of PoinTr which we train with curriculum learning to make robust against perturbations in the canonical point cloud representations. The results below show shape completion results when these pertubations are injected in the point clouds (the origin is not at the center of the full object).


Input

PoinTr

PoinTr-C (Ours)


Qualitative Results

We compare PoinTr, a 3D shape completion, against PoinTr-C, a improved version of PoinTr which we train with curriculum learning to make robust against perturbations in the canonical point cloud representations. The results below show shape completion results on data from ShapeNet dataset, when these pertubations are injected in the point clouds.


Input

Ground Truth

PoinTr

PoinTr-C (Ours)



NBV Planning in Simulation

Comparison of Pred-NBV against the baseline, non-predictive methods for NBV object reconstruction. The image of the object can be seen by clicking on the model name.

Points Seen     Points Seen
Class Model Pred-NBV Baseline Relative Improvement
747 11922 9657 20.99%
A340 8603 5238 48.62%
Airplane C-17 12916 7277 55.85%
C-130 9900 7929 22.11%
Fokker 100   10192 9100 11.32%
Atlas 1822 1722 5.64%
Maverick 2873 2643 8.34%
Rocket Saturn V 1111 807 31.70%
Sparrow 1785 1639 8.53%
V2 1264 1086 15.15%
Big Ben 4119 3340 20.89%
Church 2965 2588 13.58%
Tower Clock 2660 1947 30.95%
Pylon 3181 2479 24.80%
Silo 5674 3459 48.51%
Diesel 3421 3161 7.90%
Train Mountain 4545 4222 7.37%
Cruise 4733 3522 29.34%
Watercraft     Patrol 3957 2306 52.72%
Yacht 9499 6016 44.90%

Related Works

PoinTr: Diverse Point Cloud Completion with Geometry-Aware Transformers. Xumin Yu*, Yongming Rao*, Ziyi Wang, Zuyan Liu, Jiwen Lu, Jie Zhou. ICCV 2021.

3D ShapeNets: A Deep Representation for Volumetric Shapes. Zhirong Wu, Shuran Song, Aditya Khosla, Fisher Yu, Linguang Zhang, Xiaoou Tang, Jianxiong Xiao. CVPR 2015.

Global registration of mid-range 3D observations and short range next best views. Jacopo Aleotti; Dario Lodi Rizzini; Riccardo Monica; Stefano Caselli. IROS 2014.