Beyond Viewpoint Generalization: What Multi-View Demonstrations Offer and How to Synthesize Them for Robot Manipulation?
Authors: Boyang Cai, Qiwei Liang, Jiawei Li, Shihang Weng, Zhaoxin Zhang, Tao Lin, Xiangyu Chen, Wenjie Zhang, +6 more
Organizations: The Hong Kong University of Science and Technology (Guangzhou) · Shenzhen University · Beijing Jiaotong University · The Chinese University of Hong Kong, Shenzhen
Does multi-view demonstration truly improve robot manipulation, or merely enhance cross-view robustness? We present a systematic study quantifying the performance gains, scaling behavior, and underlying mechanisms of multi-view data for robot manipulation. Controlled experiments show that, under both fixed and randomized backgrounds, multi-view demonstrations consistently improve single-view policy success and generalization. Performance varies non-monotonically with view coverage, revealing effective regimes rather than a simple "more is better" trend. Notably, multi-view data breaks the scaling limitation of single-view datasets and continues to raise performance ceilings after saturation. Mechanistic analysis shows that multi-view learning promotes manipulation-relevant visual representations, better aligns the action head with the learned feature distribution, and reduces overfitting. Motivated by the importance of multi-view data and its scarcity in large-scale robotic datasets, as well as the difficulty of collecting additional viewpoints in real world settings, we propose RoboNVS, a geometry-aware self-supervised framework that synthesizes novel-view videos from monocular inputs. The generated data consistently improves downstream policies in both simulation and real-world environments.
Figures & tables
Figure 1: Experimental setup overview. Camera layout, example multi-view observations, and the Clean/Random environment modes.
Figure 2: Comparison between single-view and multi-view training under clean and random settings. Multi-view training improves performance across tasks, with stronger gains under the random setting.
Setting
Seen Tasks
Unseen Tasks
Average
AB
BBH
CA
MCP
MPA
OL
PCP
PS
SBH
SHB
CB
PEC
Seen
Unseen
Overall
Single-view
52
16
46
16
10
24
40
24
64
68
48
0
32.4
38.7
34.0
Multi-view
68
28
40
30
14
28
52
34
72
80
50
8
40.7 (+8.3)
46.0 (+7.3)
42.0 (+8.0)
Table 1: Multi-view supervision improves performance of a multi-task VLA model on both seen and unseen tasks.
Task
0∘
±10∘
±20∘
±30∘
±40∘
±50∘
±60∘
AB
8
42
80
70
64
56
48
BBH
14
22
32
22
20
12
8
CA
24
32
62
48
50
18
12
CB
4
20
58
30
28
18
10
Mean
12.5
29.0
58.0
42.5
40.5
26.0
19.5
Table 2: Task-wise success rates (%) under each viewpoint offset in the standard offset study.
Task
0∘
±10∘
±20∘
±30∘
±40∘
±50∘
±60∘
0∘+±10∘ Stack
AB
8
50
58
48
44
44
42
42
BBH
14
18
22
14
12
12
8
22
CA
24
22
32
26
22
18
14
32
CB
4
14
22
16
14
10
8
20
Mean
12.5
26.0
33.5
26.0
23.0
21.0
18.0
29.0
Table 3: Strict budget-matched VA experiment under fixed 0∘ evaluation. All budget-matched settings use the same data budget and training steps; the rightmost column reports the full three-view stack for reference.
Figure 3: Scaling laws of single-view vs. multi-view training on manipulation tasks. Multi-view data continues to improve performance when single-view training saturates, achieving comparable or higher performance with substantially less scene diversity.
Figure 4: Scaling behavior of multi-view demonstrations under fixed 0∘ evaluation. Each subplot shows success rate versus demonstrations per added view ( 10→50 ) for one task. The black dashed line indicates the single-view baseline trained on the origin view.
Figure 5: Grad-CAM and input-gradient analysis under fixed 0∘ evaluation. Multi-view supervision ( 0∘+±20∘ ) shifts attention toward the end-effector and manipulated objects, while single-view models exhibit stronger background sensitivity.
Linear Probe ( R2↓ )
Nonlinear Probe ( R2↑ )
Setting
Adjust Bottle
Beat Block Hammer
Click Bell
Adjust Bottle
Beat Block Hammer
Click Bell
End-effector
Object
End-effector
Object
End-effector
Object
End-effector
Object
End-effector
Object
End-effector
Object
Single-view
0.510
0.502
0.816
0.678
0.930
0.952
-0.112
-0.032
-1.220
-0.777
0.283
0.529
Multi-view
-0.116
-0.116
0.668
0.540
0.595
0.736
0.601
0.166
0.428
0.511
0.707
0.835
Δ
-0.626
-0.618
-0.148
-0.138
-0.335
-0.216
+0.713
+0.198
+1.648
+1.288
+0.424
+0.306
Table 4: Clean-only probing results ( R2 ) for manipulation-relevant states under fixed 0∘ evaluation. Linear probing tests direct linear decodability ( ↓ ), while nonlinear probing tests recoverability with a nonlinear decoder ( ↑ ). Δ denotes Multi-view − Single-view.
Metric
Random ↓
Clean ↓
BBH
CA
BBH
CA
Single
Multi
Single
Multi
Single
Multi
Single
Multi
MSE
0.0128
0.0070
0.0133
0.0087
0.0104
0.0067
0.0082
0.0074
Table 5: Policy-head MSE loss under frozen DINOv2 features ( ↓ lower is better).
Figure 6: Training dynamics of a multi-task VLA model under single-view (left) and multi-view (right) supervision. Success rates are reported over training steps (2k–5k) across six tasks. Best checkpoints are highlighted.
Method
AB
BBH
CA
CB
Method
AB
BBH
CA
CB
0∘
8
14
24
4
Crop
4
8
16
2
Perspective
6
2
6
2
Blur
8
4
8
4
Rotation
4
4
8
2
Mixed
12
16
6
4
View Aug. ( ±20∘ )
34
20
30
18
Table 6: Budget-matched policy success rates of conventional 2D image augmentations versus multi-view augmentation, evaluated at the same fixed 0∘ test viewpoint (SR%).
Figure 7: Pipeline of RoboNVS. A monocular manipulation video is first converted into a temporally consistent and metric-aligned 3D representation. The resulting DW-Mesh is rendered under target camera trajectories to produce RGB projections and occlusion masks. These geometric priors condition a diffusion-based video completion model to synthesize physically plausible novel-view demonstrations.
Method
SSIM ↑
LPIPS ↓
FVD ↓
VBench ↑
ZeroNVS-ft
0.3305
0.527
64.59
0.578
ReCamMaster
0.3865
0.451
68.16
0.585
CogNVS
0.4029
0.502
76.87
0.593
TrajectoryCrafter
0.3849
0.411
48.42
0.579
EX-4D
0.4013
0.406
42.66
0.588
RoboNVS w/o Bi-Mask
0.4272
0.369
35.90
0.593
Table 7: Visual quality comparison of RoboNVS and baseline models. ↑ indicates higher is better and ↓ indicates lower is better.
Figure 8: Qualitative comparison with generative baselines. RoboNVS produces more geometrically consistent and temporally stable novel-view videos. Baseline methods often exhibit object duplication, distorted robot structures, or incomplete mask filling.
Figure 9: Real-world setup and manipulation tasks. We evaluate RoboNVS on Bell Pushing, Fruit Pick-and-Place, and Lego Pick-and-Place using a Franka Panda robot.
Figure 10: Qualitative comparison on real-world tasks. Depth alignment improves target-view geometric masks, while RoboNVS further improves video completion quality, reconstructing robot arms and end-effectors more completely than EX-4D variants.
Method
Bell Pushing
Fruit Pick-and-Place
Lego Pick-and-Place
Monocular only
5/20 (25%)
2/20 (10%)
1/20 (5%)
EX-4D
8/20 (40%)
6/20 (30%)
4/20 (20%)
EX-4D w/ DA
10/20 (50%)
8/20 (40%)
7/20 (35%)
RoboNVS
14/20 (70%)
12/20 (60%)
11/20 (55%)
Table 8: Policy success rates on real-world tasks. Each result is evaluated over 20 trials.
Table 9: Training data sources used for RoboNVS. The corpus is primarily built from OXE subsets, with additional robotic manipulation datasets added for broader embodiment coverage.
Figure 11: Dataset composition used for training RoboNVS. The training corpus contains approximately 10,000 videos, with Droid forming the largest subset due to its scene diversity and broad manipulation coverage.
Category
Robot Embodiments
Standard arms
Franka, UR5, Sawyer, Google Robot, WidowX, Xarm
Mobile / dual-arm / multi-purpose platforms
Unitree G1 edu-u3, Mobile Aloha, A1X, AIRBOT_MMK2, alpha_bot_2
AgilexCobotMagic, AgilexSplitALOHA, Galaxea R1 Lite
Appendix
Table 10: Robotic embodiments and platforms covered by the aggregated training corpus.
Diffusion Policy Training Setup
Observation modality
head_camera + agent_pos
Image encoder
ResNet-18
Image resolution
256×192
Batch size
128
Observation steps ( nobs )
3
Optimizer
AdamW
Prediction horizon
8
Learning rate
1×10−4
Executed actions ( naction )
6
LR schedule
cosine decay
Diffusion type
DDPM
Weight decay
1×10−6
Appendix
Table 11: Key training hyperparameters for Diffusion Policy (DP).
π0 Training Setup
Backbone VLM
PaliGemma 2B + LoRA
Precision
bfloat16
Vision encoder
SigLIP
Parallelization
FSDP (4 GPUs)
Action expert
Gemma 300M + LoRA
Optimizer
AdamW
Peak learning rate
2.5×10−5
Final learning rate
2.5×10−6
LR schedule
cosine decay
Warmup steps
1000
Batch size
32
Gradient clipping
1.0
Appendix
Table 12: Key training hyperparameters for π0 .
Figure 12: Visualization of stochastic initializations. Each row shows one representative task, and each column shows a different randomized evaluation rollout. The figure highlights variations in object poses and tabletop textures.
Figure 13: Visualization of the 12 manipulation tasks in RoboTwin.
View Set
AB
BBH
CA
CB
Mean
0∘
8
14
24
4
12.5
0∘+{±10∘}
54
30
46
18
37.0
0∘+{±10∘,±20∘}
60
48
58
30
49.0
0∘+{±10∘,±20∘,±30∘}
54
40
50
28
43.0
0∘+{±10∘,…,±40∘}
52
28
44
24
37.0
0∘+{±10∘,…,±50∘}
36
26
30
18
27.5
Appendix
Table 13: Success rates (%) under progressively stacked multi-view training. Starting from 0∘ , symmetric viewpoint pairs are incrementally added to the training set, while all policies are evaluated at the fixed 0∘ viewpoint.
View Set
AB
BBH
CA
CB
Mean
0∘
52
30
20
14
29.0
0∘+{±10∘,±20∘,±30∘}
68
38
38
20
41.0
0∘+{±10∘,…,±60∘}
58
34
26
16
33.5
Appendix
Table 14: VLA performance under progressively stacked multi-view training. The π0 policy is trained with the same experimental configuration as the main-text experiments, while all policies are evaluated at the fixed 0∘ viewpoint. (SR%)
Table 16: Key architectural and training hyperparameters for ACT.
Task
0∘
±10∘
±20∘
±30∘
AB
28
48
50
34
BBH
14
16
24
16
CA
12
16
16
14
CB
0
2
6
0
SBH
28
34
50
46
MPA
8
10
12
8
Appendix
Table 17: Success rate comparison of ACT policies under multi-view vs. single-view training. ACT policies trained with multi-view demonstrations consistently outperform the single-view baseline under fixed 0∘ evaluation. The best performance generally appears under moderate viewpoint offsets around ±20∘ .
Figure 14: View augmentation under alternative base viewpoints. (a) The two base viewpoints used in this study. (b) Task success rates when the base view is 40∘ or 90∘ . In both settings, multi-view training improves performance over single-view training.
Figure 15: Cross-view robustness evaluation. Policies trained with multi-view demonstrations substantially outperform single-view policies across four off-center test viewpoints. This confirms that multi-view supervision also improves robustness when the test camera moves.
Figure 16: View augmentation with DP3 using point-cloud observations. (a) Example point-cloud observations from the frontal 0∘ view. (b) DP3 success rates under progressively added viewpoints. Multi-view training improves performance even when the policy uses 3D point clouds instead of RGB images.
Policy Architecture
Training Setup
Policy type
DP3 (DDIM Diffusion)
Optimizer
AdamW
Point cloud encoder
PointTransformer
Learning rate
1×10−4
Transformer layers
2
Batch size
16
Attention heads
2
Training epochs
3000
Encoder output dim
128
Weight decay
1×10−6
UNet channels
[512, 1024, 2048]
LR schedule
cosine
Appendix
Table 18: Key architectural and training hyperparameters for DP3.
Figure 17: Qualitative comparison of generative models under a +20∘ rotation in RoboTwin. All mask-based methods are conditioned on identical masks derived from simulator ground-truth depth. RoboNVS reconstructs robot joints and object geometry more faithfully than the compared generators.
Model
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
FVD ↓
CogNVS
17.154
0.7169
0.3621
245.13
47.36
EX-4D
17.031
0.6703
0.4331
248.26
79.26
TrajectoryCrafter
16.480
0.6687
0.4714
217.33
68.47
ZeroNVS-ft
14.350
0.7065
0.5465
215.58
86.18
RoboNVS
18.839
0.7575
0.3018
132.87
33.28
Appendix
Table 19: Quantitative comparison of generative video synthesis quality in RoboTwin.
Training Data
Click Alarm Clock
Click Bell
Single-view baseline ( 0∘ only)
19/50 (38%)
5/50 (10%)
EX-4D + 0∘
36/50 (72%)
9/50 (18%)
TrajectoryCrafter + 0∘
28/50 (56%)
9/50 (18%)
CogNVS + 0∘
34/50 (68%)
35/50 (70%)
ZeroNVS-ft + 0∘
22/50 (44%)
6/50 (12%)
RoboNVS + 0∘
40/50 (80%)
38/50 (76%)
Appendix
Table 20: Policy success rates after multi-view data augmentation using different generative models. All policies are evaluated at the RoboTwin 0∘ viewpoint over 50 trials.
Figure 18: Qualitative comparison of mask-based generative inpainting. All models receive the same mask sequences. RoboNVS produces more complete robot structures, fewer ghosting artifacts, and fewer geometric distortions around the arm and the contacted object.
Figure 19: Qualitative comparison of DW-Mesh renderings constructed from different video depth prediction methods. The first row shows source views from three manipulation scenes. Each column visualizes DW-Mesh rendering from a different depth strategy. Brown boxes compare temporal depth estimators, red boxes compare metric 3D-aware models, and yellow boxes highlight why DepthCrafter w/ DA3 is cleaner than the other aligned variant.
The generalization ability of imitation learning policies for robotic manipulation is fundamentally constrained by the diversity of expert demonstrations, while collecting demonstrations across varied environments is costly and difficult in practice. In this paper, we propose a practical framework that exploits inherent scene diversity without additional human effort by scaling camera views during demonstration collection. Instead of acquiring more trajectories, multiple synchronized camera perspectives are used to generate pseudo-demonstrations from each expert trajectory, which enriches the training distribution and improves viewpoint invariance in visual representations. We analyze how different action spaces interact with view scaling and show that camera-space representations further enhance diversity. In addition, we introduce a multiview action aggregation method that allows single-view policies to benefit from multiple cameras during deployment. Extensive experiments in simulation and real-world manipulation tasks demonstrate significant gains in data efficiency and generalization compared to single-view baselines. Our results suggest that scaling camera views provides a practical and scalable solution for imitation learning, which requires minimal additional hardware setup and integrates seamlessly with existing imitation learning algorithms. The website of our project is https://yichen928.github.io/robot_multiview.
Recently, end-to-end robotic manipulation models have gained significant attention for their generalizability and scalability. However, they often suffer from limited robustness to camera viewpoint changes when training with a fixed camera. In this paper, we propose VistaBot, a novel framework that integrates feed-forward geometric models with video diffusion models to achieve view-robust closed-loop manipulation without requiring camera calibration at test time. Our approach consists of three key components: 4D geometry estimation, view synthesis latent extraction, and latent action learning. VistaBot is integrated into both action-chunking (ACT) and diffusion-based (π0) policies and evaluated across simulation and real-world tasks. We further introduce the View Generalization Score (VGS) as a new metric for comprehensive evaluation of cross-view generalization. Results show that VistaBot improves VGS by 2.79× and 2.63× over ACT and π0, respectively, while also achieving high-quality novel view synthesis. Our contributions include a geometry-aware synthesis model, a latent action planner, a new benchmark metric, and extensive validation across diverse environments. The code and models will be made publicly available.
Robotic manipulation often requires object specific programming, manual data annotation, or calibrated perception pipelines, which limits rapid deployment in practical settings. Learning from demonstration offers a more direct alternative, but collecting demonstrations can still demand human teleoperation or kinesthetic teaching. This paper presents a self supervised visual manipulation method in which a robot automatically generates demonstrations around a target pose and learns relative pose corrections directly from wrist mounted RGB images. The proposed pipeline uses ROS~2 and Isaac Sim to collect labeled image-pose pairs without requiring explicit camera to robot extrinsic calibration. Separate datasets are generated for planar refinement and coarse three dimensional approach, and a convolutional network is trained to regress relative translation and rotation from single frame RGB observations. During execution, a coarse to fine controller first approaches the object using models trained with height variation and then refines the final alignment using planar data. The method is evaluated both in simulation and on a real UR5e collaborative robot equipped with a gripper and a monocular camera. In simulation, the refinement stage reduces the final planar dispersion from 9.69 mm to 5.38 mm. In real world experiments, the system performs end to end grasp attempts on three physical objects and reaches success rates of 66.6% and 63.6% for two objects without object rotation, while still maintaining partial robustness under rotated conditions. These results show that automatically generated demonstrations can support practical visual manipulation with limited setup effort, while also exposing remaining challenges in depth prediction and object dependent generalization.
Andres Rivas, Anselmo R. Cukla, Rodrigo S. Guerra +2
Robotics and AI Lab, Technological University of Uruguay, Rivera, Uruguay · Center of Technology, Federal University of Santa Maria, Santa Maria, Brazil · Computer Science Center, Federal University of Rio Grande, Rio Grande, Brazil