MindCube Logo MindCube
CVinW @ CVPR 2026

MindCube Challenge

Spatial Question Answering from Limited Multi-View Observations

🏛️
Hosted by: The 5th Workshop on Computer Vision in the Wild (CVinW), CVPR 2026.

We are organizing the MindCube Challenge, a spatial question answering benchmark designed to evaluate spatial mental modeling from limited multi-view observations. Participants will be ranked by accuracy on a held-out test set.

Challenge Overview

Goal

Given a multi-view observation and a question, predict the correct answer for each example.

What You Do

  1. Train / fine-tune on the MindCube training set.
  2. Develop and validate on MindCube_tinybench.
  3. Run inference on the held-out test set (to be released) and submit predictions.

Data Splits

📚

Train

MindCube_train.jsonl

Public
🔬

Validation

MindCube_tinybench.jsonl

Public
🏆

Test (Held-out)

Final evaluation set

Coming Soon

Dataset: Data can be found at huggingface.co/datasets/MLL-Lab/MindCube

Format & loading: Please refer to the official instructions in the MindCube repository.

Evaluation

  • Metric: Accuracy (exact match) on the held-out test set.
  • Ranking: Teams are ranked by overall accuracy.
  • (Optional) We may additionally report accuracy by setting/sub-category for analysis.
  • Tie-break: Higher accuracy on a specific subset, then earlier submission time.

Challenge Leaderboard

Performance of submitted methods on the held-out test set.

Click on column headers to sort the results

Baseline Participants
Rank Team / Method Overall Rotation Among Around
- Random (chance) 32.35 36.36 32.29 30.66
- Random (frequency) 33.02 38.30 32.66 35.79
Challenge submissions coming soon...
Leaderboard will be updated after the test set is released and submissions are evaluated.

Submission

Submission File Format (JSONL)

Submit a single .jsonl file with one JSON object per line, containing:

  • id (string) — the question ID from the test set
  • answer (string) — the predicted option letter (e.g., "A", "B", "C", "D")
Example submission format
{"id": "among_group693_q1_5_2", "answer": "C"}
{"id": "around_group012_q3_1_0", "answer": "A"}

Requirements

  • Provide exactly one prediction for each id in the test set.
  • Duplicate IDs: Keep last / invalid submission
  • Missing IDs: Count as incorrect / invalid submission

How to Submit

1

Download the held-out test set (coming soon)

2

Generate your predictions.jsonl following the required format.

3

Name the file as: TeamName_MethodName.jsonl

4

Submit your predictions on EvalAI. Questions? Contact qinengw@u.northwestern.edu.

Submission Limit: Up to 5 submissions per day, 100 submissions total per team across the challenge
Dev Phase Deadline: May 22, 2026 (AoE)
Test Phase Deadline: May 25, 2026 (AoE)
Results Announcement: May 31, 2026

Rules

  • External data / models / APIs: Open-source models and external data are allowed. Commercial API-only (closed-source) models are disallowed. Please disclose any external resources used in your method description.
  • Human-in-the-loop labeling on test: Disallowed
  • Participants must not attempt to obtain test labels or manipulate evaluation.
  • Verification: Top teams may be asked to provide a brief method description and reproducibility details.

Baselines & Starter Kit

Baselines, data loaders, and evaluation scripts are available in the official MindCube repository:

github.com/mll-lab-nu/MindCube

Contact

For questions, please reach out via: