We introduce HumanPhys, a human-centric benchmark for real-world physical perception, and a training corpus emitted by the same pipeline. Each question targets a physically grounded quantity related to people, including depth, inter-person distance, gaze angle, displacement, velocity, heading-step trajectory, blink count, and contact-deformation strength. The rendered probes additionally test illumination inference from body and face cues and camera ego-motion, both with and without a person in the frame. All labels are derived programmatically from sensor calibration, source metadata, or renderer state, rather than written by annotators or produced by estimators on the benchmark frames. HumanPhys systematically probes six dimensions of human-centric physical perception: spatial state, kinematics, blink events, deformation, illumination, and camera pose. To the best of our knowledge, no existing MLLM benchmark-and-training corpus jointly supervises this set of human-centered physical quantities under direct metadata- or renderer-derived labels. The six dimensions appear only partially dissociable across the tested MLLMs. We benchmark a range of open- and closed-source MLLMs on HumanPhys and find that all six capability dimensions remain challenging for current models. We hope HumanPhys will support future research on multimodal systems that perceive and reason about people in the physical world.
Figures & tables
Figure 1: Left : radar of the eight MLLMs on HumanPhys, with one axis for each sub-task, grouped into the six taxonomy categories of Figure 2 ; the two proprietary models are dashed (numerical scores in Table 3 ). Right : checkpoint ablation of fine-tuning on HumanPhys and complementary spatial data across ten benchmarks, with Qwen3-VL-4B-Instruct dashed as reference; this data-mixture ablation is tabulated in Table 5 and analysed in § 4.3 (Preserving General Spatial Abilities).
Figure 2: Overview of the HumanPhys taxonomy.
Benchmark
Human-Centric
Input Type
Source
Task Taxonomy
Train Data Ava.
Image
Video
Real
Simulation
Static
Dynamic
VSI-Bench [ 60 ]
✗
✗
✓
✓
✗
✓
✗
✗
STI-Bench [ 32 ]
✗
✗
✓
✓
✗
✓
✓
✗
3DSRBench [ 41 ]
✗
✓
✗
✓
✓
✓
✗
✗
BLINK [ 20 ]
✗
✓
✗
✓
✓
✓
✗
✗
ViewSpatial [ 27 ]
✗
✓
✗
✓
✗
✓
✗
✗
Table 1: Comparison of representative spatial reasoning benchmarks. Human-Centric : humans are the targets of perception; Input Type : accepted modalities, ”Video” means temporally ordered sampled frames derived from source clips; Source : provenance of the visual data, real or simulated; Task Taxonomy : static or dynamic queried target; Train Data Ava. : whether a training corpus is released. For HumanPhys, Static and Dynamic correspond to its frame-level and temporal questions (§ 3.1 ). For HumanMoveVQA all questions are video-level multiple-choice questions about human motion, so Static is marked ✗, and Train Data Ava. denotes the authors’ own training split rather than a separately released corpus; it is compared with HumanPhys axis by axis in § 2.2 .
Figure 3: The construction pipeline of HumanPhys: (1) data collection from open-source datasets and Blender-based simulation; (2) preprocessing with metadata extraction and scene construction; (3) multi-engine QA generation with random sampling; (4) manual review and iterative refinement.
Figure 5
Spatial state
Kinematics
Event
Deform.
Illumination
Camera pose
Model
Depth
Dist
Count
Gaze
Disp
Vel
Traj
Blink
Deform
LS-Head
LS-Body
CP-Room
CP-Human
Overall
Random
7.20
8.30
23.40
28.20
5.80
12.20
37.80
22.00
26.20
13.40
48.10
6.10
2.80
18.60
Text Only
20.60
24.00
0.00
32.55
0.00
14.80
54.03
0.00
28.00
24.58
54.19
4.62
2.32
18.03
Human
25.20
52.00
79.20
60.40
36.50
30.30
63.50
87.40
36.10
50.60
70.10
24.90
12.20
48.30
Closed-source models
GPT-5.6-Sol
37.15
29.90
70.05
79.35
20.35
40.50
64.72
87.95
46.00
27.51
57.48
30.55
18.15
46.94
Table 3: Main results on HumanPhys. Scores of eight MLLMs on the 13 sub-tasks (best per column among the eight models in bold), grouped by the six taxonomy dimensions of Figure 2 . Column keys: Dist = Distance, Disp = Displacement, Traj = Trajectory, LS = light-shadow, CP = camera-pose. Row keys: SSRL = Spatial-SSRL-7B; SpaceR/SpatialEvo/SSRL/ViLaSR are Qwen2.5-VL-7B-Instruct fine-tunes; the shaded group rows separate the closed-source (blue) from the open-source (green) checkpoints. “Overall” (our primary metric) is the question-weighted composite ∑knksˉk/2500 over the full item bank ( nk=200 ; 100 for Deform ), scoring an answer that cannot be parsed into the required type 0 and keeping it in the denominator, as lmms-eval does; the 13 sub-task columns instead average only the answers a model produced in parseable form, so they are diagnostic rather than additive, exceeding “Overall” by up to 4.06 points where truncated generations are frequent. The Human row is indicative only: ten colleagues each answered an availability-selected, non-uniform ≈ 40% subset (mean times in Table 6 , Appendix A ); the Random row is a uniform random baseline over the full question bank; the Text Only row answers from the question text alone, without any visual input.
Figure 5: One scored CP-Room QA. Step 1 shares the gold axis (yaw) but not the magnitude ( −30∘ vs. −27∘ ), passing 8 of the 10 MRA thresholds for 8/10=0.8 ; Step 2 matches exactly for 1.0 ; the sequence score averages over gold steps: (0.8+1.0)/2=0.9 .
Benchmark
Subtask
Baseline
SFT
SPAR-Bench
distance_prediction_oc
11.20
56.36 ↑
distance_prediction_oc_mv
18.05
59.62 ↑
depth_prediction_oc
33.47
59.39 ↑
depth_prediction_oc_mv
37.66
58.53 ↑
MMSI-Bench
Motion(Cam.)
22.97
32.43 ↑
Table 4: Transfer to existing benchmarks for related sub-tasks. Scores of Qwen3-VL-4B-Instruct before (Baseline) and after training with HumanPhys only (SFT ① in Table 5 ) on selected sub-tasks of SPAR-Bench and MMSI-Bench; ↑ marks the gain over the baseline. The consistent gains on distance and depth sub-tasks indicate that HumanPhys supervision transfers effectively to related tasks in existing benchmarks, while the change on Motion(Cam.) (22.97 vs. 32.43, i.e. 17/74 vs. 24/74 correct; CLT 1σ of ±4.89 and ±5.44 pp, 95% CI [−4.9,+23.8] , so this n=74 category is not individually significant) is suggestive only. _mv marks the multi-view variant of the sub-task.
Data
HumanPhys
Spatial intelligence
General
Model
HP
SpR
SpC
Overall
3DSRB.
BLINK
ViewSp.
SPAR
MMSI
VSI
WMA
MMStar
MMB.
Qwen3-VL-4B
✗
✗
✗
27.27
60.91
64.01
39.29
35.81
27.30
54.74
48.37
61.18
83.51
SFT ①
✓
✗
✗
84.92
53.31
45.78
29.59
35.71
27.20
40.77
44.06
57.00
82.56
SFT ②
✓
✓
✗
84.89
58.79
56.11
38.73
39.09
27.50
54.65
48.59
65.13
84.45
SFT ③
✓
✗
✓
86.58
57.03
58.73
42.96
42.37
26.60
43.30
47.48
59.72
82.39
SFT ④
✓
✓
✓
86.40
57.28
59.48
39.76
43.05
27.40
54.90
49.46
64.64
84.36
Table 5: Data-mixture ablation. Scores (best per column in bold) of the Qwen3-VL-4B-Instruct base model and four SFT checkpoints on HumanPhys, seven spatial-intelligence benchmarks and two general multimodal benchmarks. The Data columns mark which training corpora each run mixes (HP = HumanPhys corpus, SpR = SpaceR-151K, SpC = SpatialCorpus-331K); SFT ④ is the final model.
Figure 6: Diagnosis of CP-Room errors (Gemini-3.5-Flash, n=200 ). Left: per-step gold-vs-predicted axis confusion. Right: score-loss waterfall from a perfect mean step-MRA of 1.0 to the actual 0.274 .
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
Depth
Dist
Count
Gaze
Disp
Vel
Traj
Blink
Deform
LS-Head
LS-Body
CP-Room
CP-Human
Random
7.2
8.3
23.4
28.2
5.8
12.2
37.8
22.0
26.2
13.4
48.1
6.1
2.8
Text Only
20.60
24.00
0.00
32.55
0.00
14.80
54.03
0.00
28.00
24.58
54.19
4.62
2.32
Time (s)
40.4
25.2
96.5
35.4
44.9
180.3
131.5
82.3
136.2
1141.8
533.7
303.4
823.8
Human
25.2
52.0
79.2
60.4
36.5
30.3
63.5
87.4
36.1
50.6
70.1
24.9
12.2
Appendix
Table 6: Human study per sub-task. From top: uniform random baseline over the full bank; text-only baseline; mean human answering time per question in seconds, with cell shading proportional to time (darker = slower); and human scores on the same availability-selected, non-uniform ≈ 40% subset as the Human row of Table 3 , reported as an indicative reference only.
Reliable physical reasoning from video requires understanding how objects move, interact, and respond to interventions. Existing vision-language models (VLMs) often struggle to interpret these dynamics and reason reliably about future and counterfactual outcomes. We introduce PhysMind, a training-free agentic framework that constructs one reusable, question-agnostic executable world per video. PhysMind recovers a temporally consistent dynamic scene through object segmentation, mesh reconstruction, and 6D pose tracking, then fits analytic continuous-time dynamics and latent physical parameters without unrolling a time-stepped simulator. Given a question, it inspects, continues, or edits the world and answers from the resulting trajectories and interactions. Relative to direct chain-of-thought (CoT) reasoning with the same VLM, PhysMind improves accuracy by 38.23 points on CLEVRER and 8.08 points on Physion++. On counterfactual questions, it exceeds the strongest evaluated VLM baseline, GPT-5.5, by 19.25 points.
Chen Yang, Shenxiang Zeng, Haoyang Zhao +6
1Tsinghua University · 2The University of Hong Kong
Reacting to sudden physical hazards (catching a slipping plate, dodging a falling knife) is both a meaningful test of embodied intelligence and a hard requirement for deploying multimodal large language models (MLLMs) as the decision coreof household robots. Existing evaluations, however, probe intuitive physics passively through question answering over videos, or target deliberate, long-horizon tasks such as navigation and rearrangement; none measure whether a model can turn physical understanding into immediate, safety-critical action. We introduce ReactHuman, the first physics-grounded benchmark for human-like reactive decision-making, in which the evaluated MLLM acts as the brain of a simulated humanoid facing sudden household hazards; it spans 17 event families and over 1,000 bit-for-bit reproducible scenes with exact, annotation-free ground truth derived from 240 Hz rigid-body simulation, including adversarial objects whose appearance contradicts their physics (a foam anvil, a steel apple). We further design a five-metric suite that scores each reaction along three axes: reasonable, safe, and physically grounded. We physically execute every committed plan so that decisions have observable consequences. With this harness we evaluate seven representative MLLMs. Results show that reactive safety is far from solved: models mishandle roughly one hazard in three, act from fixed dispositions rather than the observed scene, trust appearance over motion, and miss interception points at meter scale even when the chosen action is correct; none of these failures shrink with model scale. ReactHuman thus offers both a fine-grained diagnosis and a scalable training signal toward physically grounded, safety-aware embodied agents. The benchmark can be found here: https://huggingface.co/datasets/Alan123/reacthuman-benchmark-scaled
Yizhan Li, Jianxin You, Mengyang Xiong +5
Université de Montréal · Mila – Quebec AI Institute · McGill University +2
Current multimodal models handle static image recognition well, but intuitive physical reasoning remains a weakness. Predicting how objects will move and interact from a single image is still difficult for these systems. We present BilliardPhys-Bench, a benchmark for physical reasoning in synthetic billiards environments. Its procedural engine generates randomized scenarios with friction and elastic collisions. The benchmark tests three abilities: (1) predicting ball-to-ball collisions, (2) reasoning about wall bounces, and (3) estimating final ball positions after motion stops. We evaluate recent MLLMs from the GPT, Claude, Gemini, and Qwen families. Performance drops as simulation time increases and scene geometry grows more complex. We also observe a consistent failure mode we call "stasis bias": when the correct physical outcome is harder to infer, models tend to predict no interaction. These findings show where current MLLMs break down on visual dynamics and point toward the need for better physical inductive biases in multimodal architectures.