Multi-view human mesh recovery (HMR) is broadly deployed in diverse domains where high accuracy and strong generalization are essential. Existing approaches can be broadly grouped into geometry-based and learning-based methods. However, geometry-based methods (e.g., triangulation) rely on cumbersome camera calibration, while learning-based approaches often generalize poorly to unseen camera configurations due to the lack of multi-view training data, limiting their performance in real-world scenarios. To enable calibration-free reconstruction that generalizes to arbitrary camera setups, we propose a training-free framework that leverages pretrained single-view HMR models as strong priors, eliminating the need for multi-view training data. Our method first constructs a robust and consistent multi-view initialization from single-view predictions, and then refines it via test-time optimization guided by multi-view consistency and anatomical constraints. Extensive experiments demonstrate state-of-the-art performance on standard benchmarks, surpassing multi-view models trained with explicit multi-view supervision.
Figures & tables
Figure 1: The model architectures of (a) HMR2.0, (b) CameraHMR, (c) TokenHMR, and (d) a summary of these generic single-view transformer-based HMR models. The optimizable components can be selected from three representative groups: tokens (pink/orange), model parameters (blue), or explicit SMPL parameters (green).
Figure 2: Test-time adaptation (TTA) framework for multi-view human mesh recovery. The pipeline is composed of two stages: (a) aggregating single-view SMPL estimates into a set of SMPL parameters initialization termed virtual view ; (b) Test-time adaptation refines single-view optimizable token and virtual view SMPL parameters using 2D Loss, multi-view consistency Loss, and regularization loss.
Method
MPJPE ↓
PA-MPJPE ↓
HMR2.0(a) [ 9 ]
44.8
33.6
HMR2.0(b) [ 9 ]
50.0
32.4
Single Camera
HMR2.0+scoreHMR-a [ 47 ]
47.9
28.4
HMR2.0+scoreHMR-b [ 47 ]
44.7
29.0
PostureHMR [ 46 ]
44.5
31.0
Shape Aware [ 25 ]
79.9
45.1
Table 1: Comparison on the Human3.6M dataset. Methods are grouped into single-view, multi-view calibration-free, and multi-view calibration-requiring approaches. Bold and underline indicate the best and second-best results respectively.
Method
MPJPE ↓
PCK ↑
AUC ↑
PaFF [ 16 ]
48.4
98.6
67.3
U-HMR [ 23 ]
39.7
74.0
99.4
HeatFormer [ 30 ]
39.8
99.5
72.8
Ours (TokenHMR)
45.2
99.9
79.6
Ours (HMR2.0)
40.3
99.6
80.7
Ours (CameraHMR)
39.0
99.9
83.8
Table 2: Comparison results on MPI-INF-3DHP dataset with multi-view methods. Bold indicates the best result, Underline indicates the second-best result.
Method
MPJPE ↓
PCK ↑
AUC ↑
HeatFormer
45.74
99.15
68.93
Ours(CameraHMR)
43.71
99.44
80.62
Table 3: Comparison results on MPI-INF-3DHP dataset with cross camera settings.
Components
Camerahmr
HMR2.0
TokenHMR
Virtual View
TTA
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
✗
✓
27.8
22.7
35.1
24.1
43.9
27.5
✓
✗
44.2
29.9
44.4
24.0
37.1
25.7
✓
✓
26.9
20.6
31.6
21.5
32.6
23.2
Table 4: Ablation study on the effects of Virtual View design and TTA.
Camerahmr
HMR2.0
TokenHMR
Strategy
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
No Virtual View
27.8
22.7
35.1
24.1
43.9
27.5
T-pose
27.2
21.2
32.5
22.4
33.8
23.6
Averaged
27.1
20.7
32.1
21.7
33.5
23.3
Weighted
26.9
20.6
31.6
21.5
32.6
23.2
Table 5: Ablation study on virtual view initialization strategy.
Camerahmr
HMR2.0
TokenHMR
Guidance
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
anatomical (ana)
39.9
29.4
35.2
24.6
33.5
24.5
keypoint (kp)
39.6
28.5
35.0
24.0
33.2
23.7
kp+ana
36.8
27.2
32.3
22.5
33.0
23.6
kp+ana+consistency (con)
27.3
20.9
32.2
21.6
32.9
23.4
kp+ana+con+regularizer
26.9
20.6
31.6
21.5
32.6
23.2
Table 6: Ablation study on TTA loss components.
Camerahmr
HMR2.0
TokenHMR
Component
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
SMPL Parameters
58.2
32.2
53.0
31.9
48.4
31.1
Decoder
30.8
22.8
37.2
23.3
36.9
27.5
Learnable Tokens
29.7
20.9
36.0
23.0
35.2
25.7
Learned Tokens
26.9
20.6
31.6
21.5
32.6
23.2
Table 7: Ablation study on single-view backbone optimizable component.
Camerahmr
HMR2.0
TokenHMR
Component
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
Pose
31.6
21.9
35.2
24.6
34.6
23.3
Pose+Orientation
29.0
21.4
33.4
22.0
34.4
23.3
Pose+Orientation+Shape
26.9
20.6
31.6
21.5
32.6
23.2
Table 8: Ablation study on Virtual-view Optimizable Component.
Figure 3: Mesh alignment on the Human3.6M [ 14 ] (left) and MPI-INF-3DHP [ 31 ] (right). From left to right: input image, mesh at Step 0, and mesh at step 200.
Figure 4: TTA 2D clues alignment. Green markers denote the pseudo ground-truth from 2D detector, while the red markers represent the model’s predictions.
Hyper-parameter
Camerahmr
HMR2.0
TokenHMR
η
6e−2
1e−1
6e−2
λkp
3e−1
3e−1
3e−1
λana
3e−1
3e−1
3e−1
λreg_orient
3e1
1e1
1e1
λreg_pose
1e−1
1e−1
1e−1
λreg_betas
2e−2
2e−2
2e−2
Table 9: Hyper-parameters for each model.
Steps
MPJPE ↓
PA-MPJPE ↓
AITI(s) ↓
0
44.23
29.86
0.03
50
36.54
26.64
0.63
100
30.36
23.26
1.26
150
28.52
22.17
1.88
200
27.56
21.61
2.50
Table 10: Inference time with star-structured consisntecy graph.
# of view
MPJPE ↓
PA-MPJPE ↓
2
31.2
23.0
3
29.5
22.0
4
26.9
20.6
Table 11: Ablation study on the number of views.
learning rate
MPJPE ↓
PA-MPJPE ↓
1e−2
29.8
21.1
3e−2
27.4
21.0
6e−2
26.9
20.6
1e−1
29.5
22.0
Table 12: Ablation study on learning rate.
Camerahmr
HMR2.0
TokenHMR
Steps
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
50
35.6
25.9
35.4
22.0
35.1
24.3
100
29.9
22.3
32.4
21.5
33.5
23.6
150
28.0
21.2
31.6
21.5
32.8
23.3
200
26.9
20.6
31.6
21.5
32.6
23.2
250
27.4
21.0
31.7
21.5
32.7
23.3
Table 13: Ablation study on TTA steps.
CameraHmr
HMR2.0
TokenHMR
2D detector
EPE
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
w/o evaluation data(ours)
5.94
26.9
20.6
31.6
21.5
32.6
23.2
w/ 1k evaluation data
5.05
23.8
18.0
30.1
20.3
31.7
22.2
w/ 2k evaluation data
4.74
21.8
16.1
29.9
20.1
31.5
21.6
w/ whole evaluation data
2.41
19.0
13.2
27.6
18.3
31.0
21.4
ground truth
0
15.8
10.4
26.7
17.5
30.0
20.7
Table 14: Ablation study on quality of 2D detector.
Camerahmr
HMR2.0
TokenHMR
TTA Strategy
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
MPJPE ↓
PA-MPJPE ↓
w/o gradient clip norm
30.5
22.5
37.0
24.6
35.2
24.1
w/ gradient clip norm
26.9
20.6
31.6
21.5
32.6
23.2
Table 15: Ablation study on gradient clip norm during TTA
Figure 5: TTA 2D clues alignment. Green markers denote the pseudo ground-truth from 2D detector, while the red markers represent the model’s predictions.
Figure 6: Qualitative comparison between HeatFormer and our method on the Human3.6M dataset. Pink meshes denote our predictions, while white meshes correspond to HeatFormer (iteration 4).
Figure 7: Mesh recovery and TTA alignment on real-world scenarios using the CVLab–EPFL Basketball Sequence. Red boxes highlight the misalignment in the initial predictions (Step 0).
Guangdong Provincial Key Laboratory of Visual Media and Multidimensional Intelligence, College of Computer Science and Software Engineering, Shenzhen University, China · City University of Hong Kong, China