UniMetric: Universal Metric Scale Recovery for Visual Geometry Foundation Models
Authors: Lei Yang, Yuner Zhang, Ziyang Liu, Ziying Song, Kai WU, Yiyang Gao, Jiangtao Su, Yiming Li
Organizations: Nanyang Technological University · Carnegie Mellon University · The Hong Kong Polytechnic University · Tongji University · University of Toronto · Tsinghua University
Recent advances in multimodal foundation models, exemplified by GPT-6 Astra, raise the prospect of general-purpose embodied reasoning and planning. Using Internet videos for embodied pretraining calls for reliable physical-scale annotations. Yet visual geometry foundation models often recover scene structure and camera motion without reliable metric scale. We show that uncertain size priors of familiar objects can jointly constrain a reconstruction's shared scale. Building on this insight, we present UniMetric, a universal and training-free metric scale recovery framework for geometry foundation models, without additional sensors or task-specific metric supervision. Specifically, Metric Prior Acquisition elicits object height intervals from a vision-language model. Semantic-Geometric Alignment measures reconstructed object heights along the estimated support-surface normal in each frame and converts the priors into scale intervals. Global Scale Recovery reconciles these intervals through a convex objective, yielding a jointly feasible scale when they overlap and a unique compromise otherwise. The estimated sequence-level scale is applied uniformly to reconstructed points and camera translations. Controlled experiments with real VLM priors show that combining observations improves scale accuracy with exact relative object heights. To evaluate metric accuracy on GFM reconstructions without ground-truth scale alignment, we introduce MetricBench, covering twelve embodied, driving, and roadside subsets with sensor-derived ground truth. Across nine geometry foundation models, UniMetric reduces mean depth Abs Rel, reconstruction Chamfer distance, and trajectory error by 54.2%, 83.8%, and 65.6%, respectively, improving every model on all three tasks at the suite level. We release the UniMetric code and MetricBench data.
Figures & tables
Figure 1: Uncertain object-size priors jointly constrain metric scale. (a) A vision–language model provides plausible height intervals for familiar objects across frames. (b) Combined with reconstructed object heights, these intervals constrain a shared scale. A candidate consistent with one object may violate another’s prior; their joint constraints narrow the admissible range. Here, s^ and sgt denote the estimated and reference scales. (c) UniMetric improves metric depth accuracy across nine geometry foundation models on MetricBench’s driving-and-infrastructure and embodied-AI suites. Curves compare original (None) and scale-corrected (UniMetric) predictions using δ1 (%, higher is better), averaged equally over six subsets per suite. Evaluation uses no ground-truth scale alignment.
Figure 2: Joint scale estimation with real VLM height priors and exact relative heights. (a) Available frame–object observations per sequence; the dashed line marks the budget of 50 observations. (b) Mean absolute relative scale error as the observation budget increases. (c) Scale-induced distance error computed from the results in (b) at K=20 ; the inset shows the uncorrected reference.
Dataset
K=1
K=10
K=20
K=50 [95% CI]
Reduction (%)
nuScenes
7.245
2.707
2.152
1.691 [1.178, 2.279]
76.7
JRDB
6.627
2.761
2.275
2.175 [1.762, 2.576]
67.2
3EED
5.435
1.954
1.501
1.097 [0.768, 1.441]
79.8
V2X-Radar-I
4.526
1.717
1.337
1.086 [0.886, 1.310]
76.0
Table 1: Scale recovery with different observation budgets. K is the maximum number of frame–object observations per sequence. Mean absolute relative scale error (MARE) is reported in percent (lower is better). Brackets give sequence-bootstrap 95% confidence intervals. Reduction is relative to K=1 .
Figure 3: Overview of UniMetric. Metric Prior Acquisition obtains object height intervals and masks from RGB images. Semantic–Geometric Alignment measures reconstructed heights along frame-specific support directions and converts the priors into scale intervals. Global Scale Recovery combines these intervals through a weighted convex objective, yielding a shared scale for reconstructed geometry and camera translations.
Dataset
Hardware platform(s)
Reference
Seq.
Frames
Median depth (m)
Driving and infrastructure
KITTI
passenger vehicle
LiDAR
96
5,211
11.755
nuScenes
passenger vehicle
LiDAR
116
4,627
11.585
Waymo
passenger vehicle
LiDAR
149
5,951
19.095
Argoverse
passenger vehicle
LiDAR
70
6,613
21.215
V2X-Radar-I
roadside unit
LiDAR
30
1,092
36.865
Table 2: MetricBench: platforms, sensor references, and physical scale. Counts refer to the evaluated subsets. Reference identifies the sensor source of geometry; trajectory references use dataset metric poses. Median depth is computed from valid projected sensor samples in metres. Seq.: sequences; UGV: unmanned ground vehicle. Subset construction and complete scale statistics are given in Appendix D .
Model
Scale Recovery
Autonomous Driving and Infrastructure
Embodied AI
KITTI
nuScenes
Waymo
Argoverse
V2X- Radar-I
DAIR- V2X-I
CEAR
JRDB
Fusion Portable
DROID
Humanoid Everyday
3EED
VGGT
None
0.974
0.983
0.983
0.974
0.943
0.965
0.850
0.805
0.949
0.439
0.359
0.936
UniMetric
0.722
0.316
0.311
0.311
0.392
0.866
0.551
0.520
0.676
0.332
0.335
0.534
VGGT- Ω
None
0.971
0.979
0.983
0.972
0.949
0.966
0.786
0.790
0.885
0.294
0.311
0.937
UniMetric
0.347
0.152
0.154
0.244
0.123
0.542
0.538
0.312
0.331
0.284
0.221
0.343
π3
None
0.190
0.297
0.165
0.282
0.341
0.704
0.328
0.310
0.330
0.315
1.009
0.354
Table 3: Metric depth estimation on MetricBench. Absolute relative depth error (Abs Rel, lower is better) before (None) and after UniMetric correction, without ground-truth scale alignment. Bold marks the better result within each None/UniMetric pair. DA-3 denotes Depth Anything 3.
Model
Scale Recovery
Autonomous Driving and Infrastructure
Embodied AI
Abs Rel ↓
δ1(%)↑
CD (m) ↓
ATE (m) ↓
Abs Rel ↓
δ1(%)↑
CD (m) ↓
ATE (m) ↓
VGGT
None
0.970
0.0
20.186
42.574
0.723
11.5
5.354
10.302
UniMetric
0.486
48.9
4.038
14.878
0.491
35.5
1.189
6.406
VGGT- Ω
None
0.970
0.0
19.167
42.332
0.667
13.8
4.763
9.885
UniMetric
0.260
73.8
1.292
6.746
0.338
55.7
0.628
2.037
π3
None
0.330
33.0
2.506
8.869
0.441
34.1
0.880
3.298
Table 4: Suite-averaged metric geometry on MetricBench. Metrics are averaged equally over applicable subsets; Average further averages over the nine models. δ1 denotes depth accuracy within a factor of 1.25 (%), CD denotes Chamfer distance (m), and ATE denotes mean absolute trajectory error (m). Roadside subsets are excluded from ATE. Bold marks the better result within each None/UniMetric pair.
Model
Scale Recovery
Autonomous Driving and Infrastructure
Embodied AI
KITTI
nuScenes
Waymo
Argoverse
V2X- Radar-I
DAIR- V2X-I
CEAR
JRDB
Fusion Portable
DROID
Humanoid Everyday
3EED
VGGT
None
23.094
15.127
20.034
16.584
22.986
23.293
3.216
3.466
18.317
0.224
0.119
6.783
UniMetric
6.797
1.850
3.073
1.737
4.089
6.685
1.222
1.418
2.859
0.187
0.117
1.328
VGGT- Ω
None
22.773
14.594
19.060
15.462
21.698
21.415
2.555
3.090
15.848
0.158
0.151
6.778
UniMetric
1.906
0.726
0.630
1.215
1.244
2.033
1.037
0.772
0.653
0.118
0.135
1.053
π3
None
1.668
1.710
0.848
1.596
3.454
5.761
0.893
0.952
0.971
0.090
0.259
2.116
Table 5: 3D reconstruction across autonomous-driving, infrastructure, and embodied-AI benchmarks. We report CD (Chamfer distance) in metres; lower values are better. Bold marks the better result within each None/UniMetric pair. DA-3 denotes Depth Anything 3. Results use the evaluation subsets described in Sec. D.1 .
Model
Scale Recovery
Autonomous Driving
Embodied AI
KITTI
nuScenes
Waymo
Argoverse
CEAR
JRDB
Fusion Portable
DROID
Humanoid Everyday
3EED
VGGT
None
83.455
24.125
34.825
27.892
8.296
2.418
41.462
0.015
0.150
9.471
UniMetric
36.194
5.146
12.331
5.840
8.838
2.397
21.360
0.015
0.158
5.666
VGGT- Ω
None
83.272
23.792
34.364
27.901
7.374
2.442
39.863
0.007
0.136
9.485
UniMetric
15.511
2.476
5.090
3.906
2.715
0.921
4.238
0.009
0.101
4.237
π3
None
15.176
6.738
5.780
7.781
3.054
0.964
10.318
0.018
0.346
5.090
Table 6: Ego pose estimation across autonomous-driving and embodied-AI benchmarks. We report ATE Mean (mean absolute trajectory error): the average camera-position error in metres after rigid alignment of each sequence with scale fixed to 1; lower is better. Bold marks the better result within each None/UniMetric pair; ties at the displayed precision are not bolded. DA-3 denotes Depth Anything 3.
Scale calibration
nuScenes
FusionPortable
Abs Rel ↓
δ1↑
CD ↓
ATE ↓
Abs Rel ↓
δ1↑
CD ↓
ATE ↓
None
0.979
0.0
14.594
23.792
0.885
0.9
15.848
39.863
Depth Pro
0.212
55.6
1.107
5.134
0.543
22.6
9.378
66.352
UniDepth v2
0.278
53.1
1.638
13.515
0.485
14.8
1.450
23.485
Depth Anything V2
0.347
29.0
1.705
11.423
0.396
47.0
0.702
10.855
ZoeDepth-NK
0.218
65.9
1.044
6.965
0.432
49.4
3.940
56.668
Table 7: Scale calibration of VGGT- Ω predictions. All rows rescale the same GFM outputs by one factor per sequence, estimated from metric depth ( Sec. C.2 ) or by UniMetric. Oracle (gray) fits the factor to ground truth separately for each metric. Bold and underline mark the best and second-best non-oracle results.
Variant
nuScenes
FusionPortable
Abs Rel ↓
δ1↑
CD ↓
ATE ↓
Abs Rel ↓
δ1↑
CD ↓
ATE ↓
Point priors
0.172
79.1
0.989
5.231
0.452
47.4
1.806
19.430
Uniform weights
0.180
67.5
1.235
5.902
0.469
46.9
1.828
22.636
Single anchor
0.334
45.4
1.983
21.643
0.683
18.0
6.086
48.649
UniMetric (full)
0.152
82.0
0.726
2.476
0.331
52.2
0.653
4.238
Table 8: Design ablations of UniMetric with VGGT- Ω . The variants replace scale intervals with their midpoints (Point priors), assign equal weights to valid observations (Uniform weights), or retain only the lowest-weight observation (Single anchor). Bold and underline mark the best and second-best results.
Figure 4: Qualitative scale recovery with VGGT- Ω on CEAR (top) and KITTI (bottom). Depth maps and camera trajectories compare predictions before (None) and after (UniMetric) scale correction. Point-cloud views show the highlighted regions and their measured heights alongside LiDAR references. These measurements cover visible regions rather than complete objects. GT denotes ground truth; rel. denotes the original reconstruction unit.
Figure 5: Camera trajectory scale recovery across eight GFMs. Rows show models; columns show selected scenes from FusionPortable, CEAR, nuScenes, Waymo, and KITTI. Trajectories are projected onto the Z – X plane (horizontal–vertical). GT and UniMetric (Ours) are in metres; Model retains its original relative scale. Scene labels give the GT path length. Red dots mark the common starting point; insets magnify the original predictions. GT denotes ground truth.
Appendix figures & tables23 assets
Supplementary material from the paper’s appendix.
Appendix
Figure S1: Height-only user-prompt template, adapted for height-prior acquisition. {semantic_class} is replaced by the annotated category. The output specifies a height interval in metres and its confidence.
Figure S2: General object-anchor prompt template. The task parameter {ANCHOR_GROUP} selects movable objects or static scene elements; the template fixes the selection criteria, the physical-height interval, and the response format without a dataset-specific category inventory.
Figure S3: General support-surface prompt template. The VLM returns a semantic label and an image region for the most reliable support surface; its normal is then estimated from the reconstructed geometry ( Sec. 3.2 ).
Component
Setting
VLM
seed-1.8-max
Sampling temperature
0.2
Extended reasoning
Disabled
Segmentation model
SAM2.1 Hiera Large
Segmentation prompt and output
Bounding box; one mask per region
Category reliability weights
0.95 / 0.85 / 0.70 / 0.55
Appendix
Table S1: Shared inference and optimization settings. Optional category metadata is separate from the common prompt; geometric confidence filtering follows the GFM configuration.
Dataset
Median depth (m)
P90 depth (m)
Trajectory / seq. (m)
KITTI
11.755
29.345
167.160
nuScenes
11.585
40.495
94.325
Waymo
19.095
47.595
135.491
Argoverse
21.215
53.165
109.193
V2X-Radar-I
36.865
68.115
–
DAIR-V2X-I
33.655
81.245
–
Appendix
Table S2: Physical scale of each subset. Median and 90th-percentile (P90) projected reference depth and mean metric trajectory length per sequence. Dashes mark static roadside cameras excluded from ego-pose evaluation.
Model
Scale
KITTI
nuScenes
Waymo
Argoverse
V2X-Radar-I
DAIR-V2X-I
Recovery
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
VGGT
None
0.974
0.0
0.983
0.0
0.983
0.0
0.974
0.0
0.943
0.0
0.965
0.0
UniMetric
0.722
46.7
0.316
57.7
0.311
42.9
0.311
51.1
0.392
45.6
0.866
49.3
VGGT- Ω
None
0.971
0.0
0.979
0.0
0.983
0.0
0.972
0.0
0.949
0.0
0.966
0.0
UniMetric
0.347
58.2
0.152
82.0
0.154
77.9
0.244
67.4
0.123
86.5
0.542
71.0
π3
None
0.190
64.7
0.297
20.3
0.165
68.7
0.282
25.3
0.341
18.2
0.704
0.8
Appendix
Table S3: Quantitative depth estimation on six autonomous driving benchmarks. Abs Rel (absolute relative error; lower is better) measures relative depth error; δ1 is the fraction of depths within a factor of 1.25 of reference depth, reported in percent (higher is better).
Model
Scale
CEAR
JRDB
FusionPortable
DROID
Humanoid Everyday
3EED
Recovery
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
Abs Rel ↓
δ1(%)↑
VGGT
None
0.850
0.1
0.805
0.2
0.949
0.2
0.439
33.1
0.359
35.5
0.936
0.1
UniMetric
0.551
43.7
0.520
35.1
0.676
18.2
0.332
40.9
0.335
40.4
0.534
34.9
VGGT- Ω
None
0.786
0.4
0.790
0.5
0.885
0.9
0.294
42.6
0.311
38.2
0.937
0.1
UniMetric
0.538
65.3
0.312
54.9
0.331
52.2
0.284
51.5
0.221
60.1
0.343
50.2
π3
None
0.328
47.4
0.310
39.0
0.330
31.8
0.315
49.5
1.009
4.3
0.354
32.9
Appendix
Table S4: Quantitative depth estimation on six embodied AI benchmarks. Abs Rel (absolute relative error; lower is better) measures relative depth error; δ1 is the fraction of depths within a factor of 1.25 of reference depth, reported in percent (higher is better).
Model
Scale
KITTI
nuScenes
Waymo
Argoverse
V2X-Radar-I
DAIR-V2X-I
Recovery
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
VGGT
None
14.798
17.982
17.519
22.928
23.318
27.824
26.115
31.689
38.772
42.720
39.580
46.124
UniMetric
9.622
11.842
5.613
9.099
7.653
10.055
8.387
12.292
15.102
18.630
19.193
24.132
VGGT- Ω
None
14.799
17.988
17.455
22.824
23.142
27.529
26.197
31.729
38.872
42.672
39.962
46.505
UniMetric
5.140
9.442
3.061
6.885
3.726
6.568
6.675
11.954
5.029
8.210
9.063
13.800
π3
None
3.010
4.899
5.659
8.776
4.085
6.110
7.854
11.170
14.543
17.074
24.687
28.306
Appendix
Table S5: Supplementary depth estimation on six autonomous driving benchmarks. MAE (mean absolute error) summarizes average metric-scale depth error, while RMSE (root mean square error) emphasizes larger errors. Both are in metres; lower is better.
Model
Scale
CEAR
JRDB
FusionPortable
DROID
Humanoid Everyday
3EED
Recovery
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
VGGT
None
3.633
4.641
6.386
8.146
9.811
12.805
0.508
0.695
0.347
0.472
13.116
16.615
UniMetric
2.238
3.136
3.645
5.456
6.345
9.117
0.391
0.542
0.328
0.452
6.138
9.111
VGGT- Ω
None
3.339
4.281
6.253
7.884
9.247
12.108
0.335
0.442
0.314
0.425
13.148
16.624
UniMetric
1.891
2.836
2.329
3.951
2.665
4.607
0.291
0.393
0.256
0.374
4.475
7.481
π3
None
1.446
2.331
2.664
4.218
3.388
5.125
0.300
0.382
0.825
0.932
5.191
8.218
Appendix
Table S6: Supplementary depth estimation on six embodied AI benchmarks. MAE (mean absolute error) summarizes average metric-scale depth error, while RMSE (root mean square error) emphasizes larger errors. Both are in metres; lower is better. Bold marks the better result within each None/UniMetric pair. DA-3 denotes Depth Anything 3. Evaluation subsets are described in Sec. D.1 .
Model
Scale
KITTI
nuScenes
Waymo
Argoverse
V2X-Radar-I
DAIR-V2X-I
Recovery
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
VGGT
None
45.367
51.918
29.785
34.824
39.999
46.320
33.105
38.572
40.887
45.105
41.042
47.989
UniMetric
22.942
26.723
8.332
11.292
14.638
17.650
9.581
12.927
15.938
19.585
20.931
26.192
VGGT- Ω
None
45.317
51.897
29.458
34.420
38.892
45.109
33.079
38.518
40.955
45.016
41.446
48.391
UniMetric
12.269
16.408
4.489
8.125
6.426
9.430
7.581
12.889
5.498
8.717
9.335
14.245
π3
None
8.557
10.743
9.214
11.803
7.331
9.445
10.445
13.500
15.238
17.910
25.513
29.335
Appendix
Table S7: Supplementary 3D reconstruction on six autonomous driving benchmarks. MAE (mean absolute error) and RMSE (root mean square error) summarize Euclidean distances between corresponding predicted and reference 3D points after rigid alignment, without estimating any additional scale. RMSE emphasizes larger discrepancies. Both are in metres; lower is better. Bold marks the better result within each None/UniMetric pair. DA-3 denotes Depth Anything 3. Evaluation subsets are described in Sec. D.1 .
Model
Scale
CEAR
JRDB
FusionPortable
DROID
Humanoid Everyday
3EED
Recovery
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
MAE ↓
RMSE ↓
VGGT
None
6.951
7.776
7.059
8.507
37.490
42.829
0.521
0.672
0.438
0.592
14.534
17.992
UniMetric
6.740
7.969
5.254
6.779
19.452
23.547
0.444
0.575
0.432
0.582
8.253
11.274
VGGT- Ω
None
6.416
7.166
6.817
8.212
35.921
41.015
0.379
0.480
0.479
0.614
14.522
17.965
UniMetric
4.934
6.054
3.538
5.095
5.374
6.896
0.307
0.423
0.445
0.583
6.786
9.606
π3
None
4.273
4.951
3.828
5.323
10.405
12.636
0.257
0.359
0.724
0.866
8.537
11.349
Appendix
Table S8: Supplementary 3D reconstruction on six embodied AI benchmarks. MAE (mean absolute error) and RMSE (root mean square error) summarize Euclidean distances between corresponding predicted and reference 3D points after rigid alignment, without estimating any additional scale. RMSE emphasizes larger discrepancies. Both are in metres; lower is better. Bold marks the better result within each None/UniMetric pair. DA-3 denotes Depth Anything 3.
Figure S4: Metric depth recovery on nuScenes (urban driving; 0–46 m). The scene contains a facade, hedges, and pedestrians at different distances. Before correction, no GFM exceeds 0.3% δ1 . A shared sequence-level scale raises the mean to 88.3%, with π3 reaching 98.5%, while retaining the spatial structure of each prediction.
Figure S5: Metric depth recovery on Waymo (residential street; 0–63 m). Parked vehicles, houses, and the receding roadway span near and far depths. A shared scale increases the mean frame-level δ1 from 0.9% to 85.2%; VGGT improves from 0.0% to 93.1%.
Figure S6: Metric depth recovery on KITTI (shopping street; 0–44 m). Nearby pedestrians and bicycles introduce occlusions and depth discontinuities. The mean frame-level δ1 increases from 0.0% to 71.3%, and π3 from 0.4% to 89.3%. Rescaling retains the predicted object boundaries.
Figure S7: Metric depth recovery on Argoverse (urban intersection; 0–70 m). Foreground vehicles and a background facade provide a comparison across distances. The mean frame-level δ1 increases from 0.4% to 63.2%; π3 and VGGT- Ω reach 92.8% and 84.8%, respectively.
Figure S8: Metric depth recovery on V2X-Radar-I (elevated roadside view; 0–86 m). Vehicles occupy a small part of a largely weakly textured road scene. The mean frame-level δ1 increases from 0.1% to 58.5%, and VGGT- Ω from 0.0% to 94.7%, illustrating scale recovery from an elevated viewpoint.
Figure S9: Metric depth recovery on DAIR-V2X-I (roadside view; 0–99 m). Foreground cars and a distant tree-lined avenue span the widest depth range among these examples. The mean frame-level δ1 increases from 0.0% to 71.7%; π3 and STream3R reach 96.7% and 95.7%, respectively.
Figure S10: Metric depth recovery on CEAR (indoor quadruped view; 0–5.5 m). A low viewpoint captures a robot, stacked boxes, and lab furniture. The mean frame-level δ1 increases from 11.4% to 88.0%, and DA-3 from 0.4% to 90.2%. For π3 , which is already close to metric, δ1 changes from 90.0% to 91.1%.
Figure S11: Metric depth recovery on JRDB (wheeled robot in a hall; 0–11 m). People at different distances appear among columns and a reflective floor. The mean frame-level δ1 increases from 0.6% to 65.1%, with 4RC and DA-3 reaching 81.6% and 80.1%, respectively.
Figure S12: Metric depth recovery on FusionPortable (handheld office capture; 0–4.9 m). Cabinets, monitors, and equipment appear beneath largely blank walls and ceiling. The mean frame-level δ1 increases from 10.2% to 93.9%, with every displayed GFM reaching at least 88.0%.
Figure S13: Metric depth recovery on DROID (tabletop manipulation; 0–3.7 m). A robot gripper reaches over small objects, with lab equipment in the background. STream3R’s δ1 increases from 0.1% to 86.4%, while π3 changes from 90.6% to 91.0%. The correction is small where the original prediction is already close to metric.
Figure S14: Metric depth recovery on Humanoid Everyday (close-range manipulation; 0–1.2 m). A gripper holds paper above a waste bin at the closest range among these examples. π3 improves from 0.1% to 96.2% δ1 , and DVLT from 2.9% to 89.1%, while VGGT and VGGT- Ω remain near 93% and 97%, respectively.
Figure S15: Metric depth recovery on 3EED (aerial view; 0–52 m). The oblique view covers roads, trees, parked cars, and pedestrians. The mean frame-level δ1 increases from 0.2% to 71.6%, with π3 and DVLT reaching 94.7% and 91.4%, respectively, from an aerial viewpoint.
Metric scale monocular geometry estimation has seen significant progress through large-scale data aggregation, yet current foundation models suffer from a persistent ''scale-collapse'' phenomenon: distant landmarks and vast landscapes are metrically underestimated. We hypothesize that this performance gap stems from a training data bottleneck, where existing metric-scale datasets are hardware-constrained to homogenous vehicle-captured LiDAR or short-range indoor scans, or consist of synthetic data that lacks the semantic complexity of the physical world. To bridge this gap, we curate a new metrically-grounded, in-the-wild dataset that we call MetricScenes, gathered from a variety of sources including Internet photo collections and stereo imagery. We estimate camera poses and initial depth maps for each scene using off-the-shelf methods, and recover absolute scale from geo-tagged metadata as well as known stereo camera baselines. We also improve the quality of depth maps derived from MetricScenes via a new two-stage Poisson completion method. Fine-tuning MoGe-2 on our dataset significantly mitigates scale-collapse and achieves superior metric accuracy in unconstrained, open-domain scenes while maintaining state-of-the-art performance on standard benchmarks.
Yuanbo Xiangli, Hanyu Chen, Xueqing Tsang +1
Cornell University · Shanghai Jiao Tong University
Scaling has powered recent advances in vision foundation models, yet extending this paradigm to metric depth estimation remains challenging due to heterogeneous sensor noise, camera-dependent biases, and metric ambiguity in noisy cross-source 3D data. We introduce Metric Anything, a simple and scalable pretraining framework that learns metric depth from noisy, diverse 3D sources without manually engineered prompts, camera-specific modeling, or task-specific architectures. Central to our approach is the Sparse Metric Prompt, created by randomly masking depth maps, which serves as a universal interface that decouples spatial reasoning from sensor and camera biases. Using about 20M image-depth pairs spanning reconstructed, captured, and rendered 3D data across 10000 camera models, we demonstrate-for the first time-a clear scaling trend in the metric depth track. The pretrained model excels at prompt-driven tasks such as depth completion, super-resolution and Radar-camera fusion, while its distilled prompt-free student achieves state-of-the-art results on monocular depth estimation, camera intrinsics recovery, single/multi-view metric 3D reconstruction, and VLA planning. We also show that using pretrained ViT of Metric Anything as a visual encoder significantly boosts Multimodal Large Language Model capabilities in spatial intelligence. These results show that metric depth estimation can benefit from the same scaling laws that drive modern foundation models, establishing a new path toward scalable and efficient real-world metric perception. We open-source MetricAnything at http://metric-anything.github.io/metric-anything-io/ to support community research.
We present FoundationGeo, a two-stage framework that explicitly bridges relative and metric prediction via spatial calibration and principled data design. Stage 1 learns a high-fidelity, affine-invariant geometry model by initializing with DINOv3 and training on a curated 10.2M-sample multi-domain corpus with complementary local-detail supervision, yielding sharp boundaries and strong cross-domain generalization. Stage 2 moves beyond global scaling by introducing lightweight pixel-wise calibration fields for metric estimation: a scale field for spatially varying metric alignment and a ray-direction correction field that mitigates directional bias in point-map geometry, together producing metrically consistent 3D point maps. Beyond model design, we identify camera intrinsic coverage, especially focal length distribution mismatch between training and test data, as a key bottleneck for zero-shot metric generalization: performance drops sharply when test intrinsics fall outside the training distribution. To address this, we synthesize additional training data across diverse focal lengths using a Blender-based data engine, repairing under-covered focal regimes and improving robustness under intrinsic shift. Extensive zero-shot evaluations across seven benchmarks show that FoundationGeo significantly strengthens cross-domain robustness, staying near the top across diverse domains while avoiding the sharp cross-domain performance drops observed in other methods. This consistency translates into the best overall performance, surpassing heavier baselines by over 5.2% on average.
Muxin Liu, Xiaoyang Lyu, Tianhe Ren +7
The University of Hong Kong · Voyager Research, DiDi Chuxing