Panoptic occupancy unifies 3D geometry, semantics, and instance identities, but its development is limited by scarce instance-aware annotations. Existing benchmarks mainly provide semantic labels reconstructed from incomplete sensor observations, while panoptic datasets have limited domain coverage or annotation completeness. We introduce PanoBench, a camera-centric panoptic occupancy prediction benchmark spanning synthetic and real-world driving scenes. It combines PanoBench-CarlaOcc, PanoBench-nuScenes, and PanoBench-KITTI360 through canonical data interfaces and unified evaluation protocols, providing multi-resolution annotations with persistent instance identities. The synthetic branch derives complete panoptic geometry from simulated meshes. For real-world data, a new pipeline reconstructs backgrounds using geometric priors and topology constraints, generates foreground mesh assets from multi-frame multi-view images, and fuses them into sparse panoptic voxels. A unified valid-mask protocol evaluates complete thing instances supported by temporal observations while scoring stuff regions at the voxel level. Analyses of observation fidelity, geometric completeness, spatial continuity, and temporal consistency demonstrate the benefits of the resulting annotations over existing occupancy benchmarks. We benchmark representative methods on semantic occupancy prediction, panoptic occupancy prediction, and 4D occupancy forecasting, and study voxel resolution, synthetic-to-real transfer, and storage efficiency. These results reveal complementary strengths of volumetric and ray-based metrics and persistent challenges in real-world instance-aware prediction. PanoBench is available at https://mias.group/PanoBench.
Figures & tables
Fig. 1: Overview of PanoBench, a unified benchmark for camera-centric panoptic occupancy prediction. By incorporating diverse driving datasets from both synthetic and real-world domains, PanoBench provides multi-resolution, high-fidelity, and temporally consistent instance annotations, establishing a unified testbed for semantic occupancy prediction, panoptic occupancy prediction, and 4D occupancy forecasting.
Dataset
Data Source
View
Sequences
Frames
Classes
Voxel Size (m)
Volume Size (m)
Instance
Valid Masks
SemanticKITTI [ 8 ]
Real
Forward
22
43,000
28
0.2
[51.2, 51.2, 6.4]
×
×
SSCBench-KITTI360 [ 11 ]
Real
Forward
9
12,865
19
0.2
[51.2, 51.2, 6.4]
×
×
Occ3D-nuScenes [ 6 ]
Real
Surround
850
34,149
17
0.4
[80.0, 80.0, 6.4]
×
✓
SurroundOcc [ 10 ]
Real
Surround
850
34,149
17
0.5
[100.0, 100.0, 8.0]
×
×
CarlaSC [ 29 ]
Synthetic
Surround
24
43,200
11
0.2, 0.4
[51.2, 51.2, 3.0]
×
×
CoHFF [ 28 ]
Synthetic
Surround
73
11,464
12
0.4
[40.0, 40.0, 3.2]
×
×
TABLE I: Comparison of dataset statistics between PanoBench and representative occupancy prediction benchmarks.
Fig. 2: Real-world panoptic occupancy reconstruction pipeline. Static background geometry is recovered by semantic LiDAR aggregation, HD map-guided ground lifting, topology-aware flat region recovery, and geometry-preserving processing of non-planar structures. For foreground thing instances, PanoBench mines high-quality multi-frame multi-view image crops, reconstructs complete mesh assets, selects a diverse prototype pool, and assigns a compatible mesh to each annotated instance. The aligned foreground meshes and scene-level background are voxelized and fused into sparse panoptic occupancy labels, from which temporally aware camera-centric valid masks are generated.
Fig. 3: Comparison of prior valid masks and the proposed valid masks. (a) Previous methods generate a valid mask for each single frame, in which camera rays leave large occluded regions invalid (gray). (b) The proposed temporal valid mask keeps three classes of regions under evaluation: \tiny{1}⃝ a currently occluded but previously observed instance, recovered by aggregating visibility over a window of T frames; \tiny{2}⃝ a partially observed instance, completed as a whole once any of its voxels is visible; and \tiny{3}⃝ stuff behind foreground instances, which remains valid to avoid occlusion-induced fragments. (c)–(e) Qualitative comparison of the raycasting-based mask, the complete ground truth, and the proposed valid mask on PanoBench-CarlaOcc.
Domain
Dataset
Voxel Size (m)
PixAcc (%)
CARLA
PanoBench-CarlaOcc
0.1
91.6
PanoBench-CarlaOcc
0.2
88.8
PanoBench-CarlaOcc
0.4
86.4
nuScenes
OpenOccupancy [ 7 ]
0.2
70.0
PanoBench-nuScenes
0.2
77.2
Occ3D [ 6 ]
0.4
69.2
TABLE II: Comparison of observation fidelity across occupancy benchmarks.
Fig. 4: Illustration of observation fidelity. Occupancy is ray-cast into the camera view and compared with 2D semantic ground truth.
Fig. 5: Comparison of geometric completeness on nuScenes. (a) BEV views of two scenes. (b) Two foreground instances, each rendered from two opposite viewpoints.
Method
Geometric IoU
Semantic mIoU
Road
Sidewalk
Terrain
Building
Vegetation
Object
Vehicle
Pedestrian
Occ3D-style [ 6 ]
38.3
32.6
66.7
60.7
29.8
18.2
27.7
40.5
5.9
11.4
SurroundOcc-style [ 10 ]
37.5
30.5
68.4
56.9
28.2
18.9
27.2
26.8
7.0
10.9
PanoBench (Ours)
58.9
52.0
82.8
82.3
54.8
18.4
27.6
45.3
59.1
46.0
TABLE III: Controlled oracle evaluation of occupancy annotation pipelines on PanoBench-CarlaOcc.
Fig. 6: Comparison of occupancy annotation pipelines on PanoBench-CarlaOcc ( Town10HD ). The ground truth is voxelized from complete scene meshes, and Occ3D and SurroundOcc denote their style-faithful reimplementations.
Domain
Dataset
Voxel Size (m)
rfp@0.1
rfp@0.2
CARLA
CarlaSC [ 29 ]
0.2
9.4
15.1
PanoBench-CarlaOcc
0.2
2.5
5.6
CarlaSC [ 29 ]
0.4
5.3
11.8
PanoBench-CarlaOcc
0.4
0.3
1.1
nuScenes
OpenOccupancy [ 7 ]
0.2
23.2
31.0
PanoBench-nuScenes
0.2
11.2
17.4
TABLE IV: Comparison of spatial continuity across occupancy benchmarks. Floating-voxel ratios are in permille (lower is better), and bold denotes the better result at the same voxel size.
Domain
Dataset
Voxel Size (m)
mIoU
IoU
CARLA
PanoBench-CarlaOcc
0.1
81.9
83.3
CarlaSC [ 29 ]
0.2
70.3
83.5
PanoBench-CarlaOcc
0.2
82.8
89.1
CarlaSC [ 29 ]
0.4
71.5
86.8
PanoBench-CarlaOcc
0.4
83.6
92.3
nuScenes
OpenOccupancy [ 7 ]
0.2
60.9
68.2
TABLE V: Comparison of temporal consistency across occupancy benchmarks. Bold denotes the better result at the same voxel size.
Fig. 7: Comparison of instance temporal consistency on nuScenes: (a) Occ3D-Panoptic [ 15 ] and (b) PanoBench-nuScenes. Voxels with the same instance identity are rendered in the same color across frames, and red and blue circles highlight two representative instances.
Background Component
Configuration
Semantic LiDAR Aggregation
✓
✓
✓
✓
Ground-Layer Lifting
✓
✓
✓
Flat-Region Recovery
✓
✓
Non-Planar Refinement
✓
PixAcc (%)
68.5
74.1
79.0
79.4
TABLE VI: Ablation study on background reconstruction components on PanoBench-nuScenes. Observation fidelity is evaluated on stuff pixels.
Method
Input Views
View Selection
IoU
LiDAR Aggregation [ 6 ]
–
–
12.4
SAM 3D [ 60 ]
Single-View
✓
61.2
TRELLIS [ 58 ]
Single-View
✓
57.0
TRELLIS-2 [ 59 ]
Single-View
✓
60.5
MV-SAM3D [ 63 ]
Multi-View
×
65.1
MV-SAM3D [ 63 ]
Multi-View
✓
67.2
TABLE VII: Ablation study on foreground mesh asset acquisition on PanoBench-CarlaOcc, measured by instance IoU (%).
Fig. 8: Representative prototype meshes from the three PanoBench subsets. Rows show (a) cars, (b) two-wheelers, (c) pedestrians, and (d) other vehicles. The examples illustrate the intra-class shape diversity retained by the prototype mesh pools across synthetic and real-world domains.
Method
PanoBench-CarlaOcc
PanoBench-nuScenes
PanoBench-KITTI360
IoU
mIoU
RayIoU@1
RayIoU@2
RayIoU@4
IoU
mIoU
RayIoU@1
RayIoU@2
RayIoU@4
IoU
mIoU
RayIoU@1
RayIoU@2
RayIoU@4
SparseOcc [ 15 ]
68.5
41.7
50.0
56.6
60.1
55.0
33.0
33.7
41.7
46.5
33.3
11.2
28.1
32.0
33.4
OPUS [ 39 ]
73.5
41.3
50.3
56.9
59.3
50.1
29.9
32.6
41.4
46.2
30.7
9.7
18.8
23.9
26.6
Panoptic-FlashOcc [ 16 ]
73.8
40.9
51.7
55.9
57.7
47.7
22.6
25.2
34.9
41.1
41.7
11.5
18.8
25.0
27.6
GaussianFormer [ 37 ]
82.2
46.2
56.4
61.0
62.8
66.5
32.6
32.8
41.8
46.7
65.3
15.6
21.1
25.5
27.1
TABLE VIII: Comparison of semantic occupancy prediction methods on PanoBench. Default voxel sizes are used, i.e. , 0.4 m for PanoBench-CarlaOcc and PanoBench-nuScenes and 0.2 m for PanoBench-KITTI360.
Method
PanoBench-CarlaOcc
PanoBench-nuScenes
PanoBench-KITTI360
IoU
mIoU
RayPQ@1
RayPQ@2
RayPQ@4
IoU
mIoU
RayPQ@1
RayPQ@2
RayPQ@4
IoU
mIoU
RayPQ@1
RayPQ@2
RayPQ@4
SparseOcc [ 15 ]
68.5
41.7
36.5
41.7
44.1
55.0
33.0
11.2
16.5
20.1
33.3
11.2
12.7
16.0
17.4
Panoptic-FlashOcc [ 16 ]
73.8
40.9
30.6
34.8
36.8
47.7
22.6
3.2
7.0
10.8
41.7
11.5
7.2
10.8
12.6
TABLE IX: Comparison of panoptic occupancy prediction methods on PanoBench under the default voxel sizes in Table VIII .
Method
PanoBench-CarlaOcc
PanoBench-nuScenes
PanoBench-KITTI360
Semantic mIoU
Geometric IoU
Semantic mIoU
Geometric IoU
Semantic mIoU
Geometric IoU
1 s
2 s
3 s
Avg.
1 s
2 s
3 s
Avg.
1 s
2 s
3 s
Avg.
1 s
2 s
3 s
Avg.
1 s
2 s
3 s
Avg.
1 s
2 s
3 s
Avg.
SparseWorld [ 47 ]
33.4
28.6
24.6
28.9
68.4
63.9
59.5
63.9
25.3
23.1
21.0
23.1
49.2
47.6
45.7
47.5
6.2
4.7
3.6
4.9
24.4
20.8
17.5
20.9
SparseWorld-TC [ 48 ]
34.5
29.8
25.7
30.0
69.3
64.8
60.4
64.8
24.9
22.7
20.8
22.8
49.2
47.6
45.9
47.6
7.7
6.1
4.8
6.2
28.6
24.8
21.1
24.8
TABLE X: Comparison of 4D occupancy forecasting methods on PanoBench under the default voxel sizes in Table VIII .
Method
Voxel Size (m)
IoU
mIoU
OPUS [ 39 ]
0.1
38.5
11.7
0.2
61.6
31.6
0.4
73.5
41.3
Panoptic-FlashOcc [ 16 ]
0.1
38.5
11.8
0.2
62.8
32.1
0.4
73.8
40.9
TABLE XI: Multi-resolution occupancy prediction on PanoBench-CarlaOcc.
Target
Method
Pretraining
mIoU
RayIoU
RayPQ
nuScenes
SparseOcc [ 15 ]
–
33.0
40.6
15.9
CarlaOcc
34.2
42.3
17.4
Panoptic-FlashOcc [ 16 ]
–
22.6
33.7
7.0
CarlaOcc
26.4
35.6
9.6
KITTI-360
SparseOcc [ 15 ]
–
11.2
31.2
15.4
CarlaOcc
11.8
31.9
15.2
TABLE XII: Sim-to-real transfer results for panoptic occupancy prediction. RayIoU and RayPQ are averaged over depth tolerances of 1, 2, and 4 m.
Dataset
Storage (GiB)
Latency (ms)
Official
Ours
↓ (%)
Official
Ours
↓ (%)
Occ3D-nuScenes [ 6 ]
2.6
1.3
48.7
11.1
1.6
85.8
Occ3D-Panoptic [ 15 ]
3.2
1.3
58.1
20.6
1.5
92.8
OpenOccupancy [ 7 ]
132.7
5.5
95.9
40.2
6.8
83.2
SurroundOcc [ 10 ]
40.3
1.2
97.1
13.5
1.9
85.8
SemanticKITTI [ 8 ]
90.6
1.2
98.7
36.3
2.1
94.1
TABLE XIII: Overall storage footprint and per-frame I/O latency of the official occupancy annotations versus our canonical sparse panoptic format. Latency is averaged over 1,000 randomly sampled frames per dataset on the same hardware.