Source note
WorldMAP: Bootstrapping Vision-Language Navigation Trajectory Prediction with Generative World Models
Summary
WorldMAP trains a navigation trajectory predictor by turning world-model-generated future views into pseudo-labeled paths. The paper argues that world models help more as supervision generators than as test-time planners for single-image vision-language navigation.
Problem
- The task is to predict a grounded, traversable navigation trajectory from one egocentric image and a language instruction in unseen environments.
- Direct vision-language models often output unstable paths that miss geometry, obstacles, or the correct stopping point.
- World models can generate plausible future views, but those views do not directly give the structured target, obstacle, and path supervision needed to train a reliable predictor.
Approach
- WorldMAP uses a teacher-student setup. The teacher uses generated future videos to build a semantic-spatial memory and a shared bird's-eye-view planning space.
- The teacher retrieves instruction-relevant views with CLIP, uses a VLM plus UniPixel to segment target regions and obstacles, projects them into BEV, and builds a cost map.
- It then runs Fast Marching Method planning on that cost map to produce trajectory pseudo-labels.
- A lightweight student VLM takes the original image and instruction and predicts waypoints directly, with a multi-hypothesis trajectory head and a best-match training loss.
- At inference time, only the student runs, so the expensive world-model and planning pipeline is used only for training.
Results
- On Target-Bench, WorldMAP reports the best ADE and FDE among compared methods: ADE 42.06, FDE 38.87, DTW 31.95.
- Against the best competing baseline, Gemini-3-Pro, WorldMAP reduces ADE from 51.27 to 42.06 for an 18.0% improvement and FDE from 67.19 to 38.87 for a 42.1% improvement; DTW is close (31.95 vs. 31.63).
- WorldMAP uses a Qwen3-VL-8B student and outperforms direct open-source VLM prediction by a large margin. For example, direct Qwen3-VL-8B scores ADE 183.93, FDE 339.58, DTW 177.33.
- It also beats the world-model-augmented baseline MindJourney, which reports ADE 152.41, FDE 250.17, DTW 84.84.
- The paper’s main concrete claim is that generated futures work better as training supervision for grounded planning than as extra test-time evidence for direct reasoning.