Feed-forward models accurately estimate camera motion and 3D geometry from short video windows. However, computational and memory costs prevent direct inference on sequences containing thousands of frames. Long videos must therefore be processed as overlapping chunks. This division produces independent local reconstructions with inconsistent coordinate frames and duplicate estimates of shared cameras. Achieving global consistency requires propagating constraints from adjacent overlaps and distant revisits across the sequence. This requirement naturally motivates pose graph optimization. However, the choice of graph level creates a trade-off. Chunk-level graphs efficiently resolve scale drift and close large loops. Yet, their rigid transformations cannot correct internal errors or conflicting frame predictions. Conversely, frame-level optimization offers local flexibility, but scaling it globally is computationally expensive and can break metric scale. HiP3R resolves this trade-off using a hierarchical pose graph. HiP3R first optimizes a robust chunk-level Sim(3) graph to establish the global layout and scale. It then holds this layout fixed and estimates one shared SE(3) camera per frame, turning overlapping window predictions into a single trajectory. Experiments across multiple benchmarks demonstrate the effectiveness of HiP3R in improving camera trajectories and 3D reconstruction. Our method applies to both chunk-based and streaming backends without additional training or fine-tuning. The codes are available at https://kkakkkka.github.io/HiP3R.
Figures & tables
Figure 1: Overlapping predictions recover local geometry in inconsistent frames. Coarse layout optimization corrects global placement and scale, but keeps each chunk’s internal cameras. Shared-camera trajectory refinement estimates one trajectory from predictions and within-chunk motion.
Figure 2: Overview of HiP3R . Frozen backends predict overlapping chunks. Stage I builds a chunk-level Sim(3) graph from overlap and loop constraints to recover layout and scale. Stage II estimates one shared SE(3) camera per frame under that layout.
Method
Mean ATE ↓
Mean RPE rot ↓
Mean RPE trans ↓
CUT3R ( Wang et al., 2025b )
44.894
4.469
1.4600
TTT3R ( Chen et al., 2026b )
23.775
5.077
0.8077
LoGeR ( Zhang et al., 2026a )
40.691
2.086
1.1035
VGGT ( Wang et al., 2025a )
20.914
3.159
1.6396
ZipMap ( Jin et al., 2026 )
28.230
2.792
0.9454
LingBot-MAP ( Chen et al., 2026a )
8.288
1.818
1.4152
Table 1: Trajectory evaluation across indoor and outdoor benchmarks. Values are dataset-macro averages of ATE (m), RPE rot ( ∘ ), and RPE trans (m). Bold marks the best result.
ATE ↓
Backend
Method
Oxford
KITTI
VBR
Mean
VGGT-Omega
Baseline
9.861
77.42
41.91
43.06
VGGT-Long (w/o loops)
1.777
110.3
85.50
65.86
VGGT-Long (w/ loops)
1.665
10.19
41.27
17.71
+ HiP3R (Ours)
1.579
9.730
22.44
11.25
VGGT
VGGT-Long (released)
9.451
48.84
99.83
52.71
Table 2: Trajectory comparison on KITTI, VBR, and Oxford, alongside the long-horizon mean.
Figure 3: Qualitative comparison between VGGT-Omega chunk placement and HiP3R .
Method
AUC@5 ↑
AUC@15 ↑
AUC@30 ↑
Chamfer ↓
F1 ↑
VGGT-Omega
29.77
50.24
63.22
0.0759
65.92
HiP3R (VGGT-Omega)
50.75
67.98
75.21
0.0272
91.26
LingBot-MAP
17.83
38.61
53.19
0.1423
61.13
HiP3R (LingBot-MAP)
22.01
51.35
66.90
0.1042
74.60
Table 3: Pose AUC and dense geometry on both backends.
Configuration
ATE ↓
Graph Build & Solve (s) ↓
Final solve (s)
Baseline
21.7751
12232.18
1404.54
+ Bounded sampling
21.7569
2004.20
1345.43
+ Fit weighting
21.7770
2077.49
1387.14
+ Progressive loops
21.5241
1477.59
688.02
Complete
17.4708
753.43
41.28
Table 4: Ablation of point sampling and progressive layout solver on extended sequences. Rows add components cumulatively. Appendix K details all test conditions.
VGGT-Omega
LingBot-MAP
ATE
RPE rot
RPE trans
ATE
RPE rot
RPE trans
Layout Only
4.9143
0.6412
0.0817
4.0517
1.1837
0.2126
Single
4.9079
0.6238
0.0695
4.0256
1.1131
0.1930
Unary
4.9067
0.6010
0.0674
4.0192
1.0871
0.1828
Motion
11.6776
0.5877
0.0619
6.5007
1.0464
0.1816
Shared
4.9061
0.5899
0.0622
4.0168
1.0549
0.1824
Table 5: Trajectory comparison on identical predictions and one optimized coarse layout.
Figure 4: Trajectory comparison on four long sequences with identical VGGT-Omega points.
Tracking Error
Runtime (s)
Dataset
Stage
ATE ↓
RPE rot ( ∘ ) ↓
RPE trans ↓
Inference
Stage solve
KITTI ( T=4541 )
Baseline
77.42
0.895
2.358
825.745
–
Layout Only
9.750(−87%)
0.202(−77%)
0.131(−94%)
896.785
5.40
Full
9.730(−0.2%)
0.154(−24%)
0.093(−29%)
896.785
0.08
VBR ( T≈12,383 )
Baseline
41.91
2.117
0.256
2283.438
–
Layout Only
22.44(−46%)
0.617(−71%)
0.075(−71%)
2511.460
200.0
Table 6: Stage-wise results on identical VGGT-Omega predictions. Layout Only is the direct coarse-layout output; Full adds shared-camera trajectory refinement on the same layout. Oxford and VBR timings are means per sequence. Inference times include all inference required for each output; solver times are reported per stage. Error subscripts give reductions relative to the preceding stage.
Appendix figures & tables15 assets
Supplementary material from the paper’s appendix.
Appendix
Refinement graph
ATE ↓
RPE rot ↓
RPE trans ↓
∣K∣
tf (s)
Overlap averaging
9.735
0.202
0.131
—
—
Uniform stride 10
9.728
0.158(−22%)
0.094(−28%)
605
0.055
Motion stride 10
9.729
0.156(−23%)
0.094(−28%)
725
0.104
Uniform stride 5
9.730
0.154(−24%)
0.093(−29%)
1059
0.075
Appendix
Table 7: Keyframe subgraph on KITTI after the same coarse A⋆ .
Consensus
Uniform s=10
Uniform s=5
Scene
T
RPE rot
RPE trans
RPE rot
RPE trans
RPE rot
RPE trans
campus_train0
12,042
0.204
0.129
0.122
0.118
0.119
0.117
spagna_train0
14,141
0.542
0.048
0.535
0.035
0.535
0.034
downtown2
2200
3.509
0.083
3.507
0.082
3.507
0.082
Appendix
Table 8: The same keyframe comparison on additional long sequences.
Dense Ft
Uniform s=5
Scene
T
ATE
RPE rot
RPE trans
ATE
RPE rot
RPE trans
Courthouse
1106
2.599
10.82
0.517
2.600
10.81
0.517
downtown1
1427
3.223
3.940
0.0875
3.223
3.940
0.0876
KITTI
4541
9.731
0.144
0.086
9.730
0.154
0.093
Appendix
Table 9: Dense fine graph versus uniform stride 5 on VGGT-Omega predictions and coarse A⋆ .
4 configured span-ordered stages, expanded to at most 8 by adaptive continuation
Keyframe subgraph ( T>2000 )
uniform stride 5 , all chunk endpoints, at least min(3,∣O∣) frames in each overlap O , correction interpolation (Appendix C )
Appendix
Table 10: Solver hyperparameters and optimization settings across backends. We use the public configurations of VGGT-Omega ( Wang et al., 2026b ) , LingBot-MAP ( Chen et al., 2026a ) , and SALAD ( Izquierdo and Civera, 2024 ) .
Dataset
Domain
#Seq.
What it tests
7-Scenes
Indoor RGB-D
38
Textureless rooms, motion blur
ETH3D
Indoor and outdoor
Mixed-scale laser-scanned scenes
Neural RGB-D
Indoor RGB-D
Cluttered rooms, fine geometry
Tanks and Temples
Outdoor structures
6
Large objects and buildings
Oxford Spires
Campus indoor and outdoor
9
Loops and scale change ( T≈320 )
KITTI seq00
Driving
1
Long outdoor loop ( T=4541 )
Appendix
Table 11: Dataset composition and experimental splits.
Split
Method
Component
Oxford
KITTI seq00
VBR
( T≈320 )
( T=4541 )
( T≈12,383 )
HiP3R (Ours)
Local baseline chunk inference ( tgN )
53.3
825.7
2283.4
Loop-window inference ( tloop )
1.6
71.0
228.0
CPU coarse + fine solves ( tsolve )
0.05
5.5
200.2
Component sum
55.0
902.3
2711.6
Appendix
Table 12: Mean pipeline component times (s) on Oxford, KITTI, and VBR. For HiP3R , component sums include chunk and loop inference and coarse and fine solves.
Method
7S
ETH
KITTI
NRGBD
Oxford
T&T
VBR
VGGT-Omega ( Wang et al., 2026b )
0.0370
0.118
77.42
0.0190
9.861
0.518
41.914
π3 ( Wang et al., 2025c )
0.0574
0.104
68.22
0.0244
12.06
0.467
87.269
GlueMap ( Pan et al., 2026 )
0.0624
0.810
193.5
0.0232
16.65
0.521
105.4
Scal3R ( Xie et al., 2026 )
0.0720
0.236
86.25
0.0471
4.573
0.572
101.535
VGGT-Long ( Deng et al., 2025 )
0.0743
0.204
48.84
0.0374
9.451
0.550
99.832
VGGT-Align ( Zhang et al., 2026b )
0.0731
0.209
69.80
0.0374
8.567
0.537
99.867
Appendix
Table 13: Per-dataset ATE on the seven public datasets (lower is better). NRGBD is Neural RGB-D, 7S is 7-Scenes, T&T is Tanks and Temples. Bold and underline mark the full-table best and second-best values in each column.
Method
7S
ETH
KITTI
NRGBD
Oxford
T&T
VBR
VGGT-Omega ( Wang et al., 2026b )
0.501
0.868
0.895
0.146
5.757
2.458
2.117
π3 ( Wang et al., 2025c )
0.510
0.729
0.218
0.0999
6.912
2.036
0.636
GlueMap ( Pan et al., 2026 )
0.507
1.755
0.535
0.0984
4.337
2.308
1.388
Scal3R ( Xie et al., 2026 )
0.520
2.036
0.215
0.0957
2.193
1.985
2.589
VGGT-Long ( Deng et al., 2025 )
0.535
1.257
0.264
0.118
5.135
2.027
0.806
VGGT-Align ( Zhang et al., 2026b )
0.536
1.258
2.141
0.118
5.109
2.027
0.808
Appendix
Table 14: Per-dataset RPE rot on the same seven datasets (lower is better). Bold and underline mark the full-table best and second-best values in each column.
Method
7S
ETH
KITTI
NRGBD
Oxford
T&T
VBR
VGGT-Omega ( Wang et al., 2026b )
0.0172
0.101
2.358
0.0109
4.044
0.128
0.2557
π3 ( Wang et al., 2025c )
0.0158
0.091
0.150
0.0091
1.999
0.106
0.1591
GlueMap ( Pan et al., 2026 )
0.0145
0.583
1.805
0.0079
2.268
0.115
8.599
Scal3R ( Xie et al., 2026 )
0.0176
0.238
0.335
0.0092
0.259
0.107
0.2260
VGGT-Long ( Deng et al., 2025 )
0.0188
0.190
0.221
0.0098
0.997
0.110
0.2292
VGGT-Align ( Zhang et al., 2026b )
0.0188
0.191
14.88
0.0098
1.053
0.110
0.2633
Appendix
Table 15: Per-dataset RPE trans on the same seven datasets (lower is better). Bold and underline mark the full-table best and second-best values in each column.
Chamfer ↓
F1 ↑
Dataset
Baseline
HiP3R
Baseline
HiP3R
ETH3D
0.0339
0.0334
98.92
99.00
Neural RGB-D
0.1310
0.0205
40.53
90.05
7-Scenes
0.0739
0.0269
58.45
87.13
Appendix
Table 16: Dense 3D reconstruction metrics (Chamfer distance and F1 score) on VGGT-Omega versus HiP3R evaluated on datasets with dense 3D ground truth.
Chamfer ↓
F1 ↑
Dataset
Baseline
HiP3R
Baseline
HiP3R
ETH3D
0.1295
0.1295
86.49
86.49
Neural RGB-D
0.1620
0.0675
42.66
65.24
7-Scenes
0.1403
0.1071
54.87
72.01
Appendix
Table 17: Dense 3D reconstruction metrics (Chamfer distance and F1 score) on LingBot-MAP versus HiP3R evaluated on datasets with dense 3D ground truth.
Dataset
VGGT-Omega ( Wang et al., 2026b )
LingBot-MAP ( Chen et al., 2026a )
C/O
ATE
vs 60/30
C/O
ATE
vs 120/32
7-Scenes
90/30
0.0366
0.0381
120/8
0.0801
0.0793
ETH3D
60/30
0.0546
0.0546
120/32
0.479
0.479
KITTI
60/16
9.352
9.736
120/32
3.508
3.508
NRGBD
60/30
0.0219
0.0219
160/32
0.0608
0.0776
Oxford
60/30
1.579
1.579
120/32
1.651
1.651
Appendix
Table 18: Chunk and overlap comparison. C/O denotes chunk size and overlap size in frames. The “vs” columns report ATE with the indicated default sizes. Bold marks a change from Table 10 .
Layout Only
Full
Sequence
T
ATE
RPE rot
RPE trans
ATE
RPE rot
RPE trans
KITTI seq00
4541
9.750
0.202
0.131
9.730
0.154
0.093
spagna_train0
14,141
10.256
0.542
0.048
10.261
0.535
0.034
campus_train1
11,671
7.381
0.230
0.076
7.387
0.157
0.045
Appendix
Table 19: Trajectory accuracy of Layout Only versus Full on the same feed-forward predictions.
Configuration
ATE
RPE rot
RPE trans
Graph Build & Solve (s)
Final solve (s)
Clean loop measurements
Baseline
21.7751
1.31094
0.11296
12232.18
1404.54
+ Bounded sampling
21.7569
1.31093
0.11280
2004.20
1345.43
+ Fit weighting
21.7770
1.31084
0.11262
2077.49
1387.14
+ Progressive loop scheduling
21.5241
1.31077
0.11070
1477.59
688.02
Complete
17.4708
1.30972
0.09834
753.43
41.28
Appendix
Table 20: Ablation of layout-solver components on extended sequences. Total time includes measurement construction and all layout solves. Final solve is the duration of the final least-squares call.
VGGT-Omega
LingBot-MAP
Output
Chamfer ↓
F1 ↑
Output
Chamfer ↓
F1 ↑
Native
0.0759
65.92
Native
0.1423
61.13
Layout Only
0.0273
91.20
Layout Only
0.1049
74.49
Full
0.0272
91.26
Full
0.1042
74.60
Appendix
Table 21: Dense geometry across optimization stages. F1 is reported in percent.
State Key Laboratory of Human-Machine Hybrid Augmented Intelligence, Institute of Artificial Intelligence and Robotics, Xi’an Jiaotong University, China · University of East Anglia, Norwich, NR47TJ, United Kingdom