AquaWorld: Structure-Consistent Underwater World Generation for Robot Simulation
Authors: Bin Peng, Tiandong Zhang, Ruidong Wang, Min Luo, Shuo Wang
Organizations: State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing, China · School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, China · Ocean College, Zhejiang University, Zhejiang, China
Underwater robot simulation requires diverse environments in which terrain, scene composition, tasks, and currents remain mutually consistent. We present AquaWorld, a world-generation framework that preserves these relationships through shared terrain structure. A language-conditioned plan generates 3D terrain and shared structural references that guide asset placement, task definition, and inflow specification under stochastic variation. The framework incorporates over 10,000 underwater-compatible assets, predicts reusable terrain-conditioned mean-flow fields through a CFD-supervised residual model, and supports conventional underwater vehicles and bio-inspired robotic fish. On 24 paired terrains, structure-consistent randomization produces substantially better cross-factor consistency than independent randomization. In a matched-budget policy-training comparison, structurally coherent randomization achieves a validation success rate 21% higher than independent randomization. In separate physical experiments, a simulation-trained visual navigation policy succeeds in 95% of physical tank trials without updating its perception or control modules. Overall, AquaWorld provides a practical way to generate varied underwater environments while retaining the structural relationships needed for flow simulation and robot learning.
Figures & tables
Framework
World construction
Language control
Terrain-linked outputs
Flow modeling
Robot models
Infinigen [ 7 ]
Procedural
–
Assets
–
–
DreamSea [ 15 ]
Learned
–
–
–
–
OysterSim [ 11 ]
Asset synthesis
–
–
–
–
ChatSim [ 8 ]
Scene editing
✓
–
–
–
OceanSim [ 6 ]
Imported
–
–
–
Single-body
HoloOcean [ 3 , 9 ]
Image-conditioned
–
Assets
Prescribed
Single-body
TABLE I: Comparison of representative underwater world-generation and simulation frameworks.
Fig. 2: Language-conditioned terrain generation and structure-aware scene instantiation. A validated ScenePlan selects terrain operators to generate 3D geometry and structural references, which are then used for scene and task instantiation.
Fig. 3: Terrain-conditioned mean-flow generation. Terrain features and resolved inflow conditions drive a residual encoder–decoder. Regional CFD supervision distinguishes the full field, near-wall and task regions, wake and reverse-flow regions, and upper and far downstream regions. The illustrated slices compare reference and predicted mean velocities.
Fig. 4: Representative robot morphologies supported in AquaWorld. The simulation includes conventional underwater vehicles and articulated bio-inspired robots with multi-link bodies or discretized undulating fins.
Method
Reg.
Align.
Full (%)
Near (%)
Task (%)
Wake RMSE/ U
Global supervision
–
✓
4.48
13.08
8.07
0.238
Regional supervision
✓
–
4.52
12.53
7.33
0.225
Full model
✓
✓
4.42
12.02
6.93
0.223
TABLE II: Ablation of regional supervision and inflow alignment on the development set.
Fig. 5: Visual navigation and sim-to-real transfer. (a) Target- and obstacle-perception CNNs process onboard RGB observations, followed by an MLP PPO policy for robot control. (b) Representative runs in the simulated tank and the corresponding physical setup, showing overhead trajectories and onboard camera views during target approach and obstacle avoidance.
Fig. 6: Matched world-generation comparison. Independent and structurally coherent randomization use the same terrain and matched randomized resources. AquaWorld retains terrain-relative scene, flow, and task associations through shared structural references. Numerical annotations in the image describe the displayed example.
Metric
Independent
AquaWorld
Flow-direction error ↓
31.41∘
6.68∘
Asset–support agreement ↑
50.65%
98.00%
Task–channel coverage ↑
73.25%
100.00%
TABLE III: Cross-factor consistency over 24 matched terrain pairs.
Marine robotic simulation provides a safe and inexpensive method of developing and testing algorithms for unmanned underwater vehicle (UUV) and unmanned surface vessel (USV) autonomy and perception before full field deployment. However, these simulations are often limited by the availability of simulated environments. Current marine robotics simulation suites offer manual ways to edit or create environments, but they require existing data or specialized knowledge of the environment system. To address these issues, we introduce a novel Unreal Engine 5 level generation pipeline that enables automatic creation of coastal environments for HoloOcean. Our pipeline relies on a user-provided overhead image of a coastal scene. The pipeline then uses the image to generate height map data, as well as automatically select assets and place them in the environment.
Training and validation of Embodied AI for social navigation critically depends on realistic simulation environments, yet many current approaches fail to find a balance between realism and simulability. We propose D3D-GEN, a novel world generation system that combines a domain agent with a retrieval-augmented generation (RAG) pipeline grounded in that domain. Our system enables users to rapidly generate domain-grounded, fully interactive 3D worlds by automating both the collection of domain knowledge and the synthesis of realistic floorplans and object placements, without dependence on any fixed 3D model database. Given a domain description prompt, the research agent collects publicly accessible domain-specific data and constructs a persistent domain database. Using this database, our RAG pipeline generates plausible floorplans and object placements by dynamically querying a user-provided semantic database, which can be easily extended or modified. The output is a fully interactive 3D world loadable by the popular simulators Isaac Sim and Gazebo. With our approach, we have built databases for several common domains (indoor residential, hospital, office) and generated dozens of distinct, plausible simulation environments for each domain. We present D3D-GEN with a local web frontend that facilitates rapid, interactive world generation for robot simulation.
Anh Duc Do, Volodymyr Shcherbyna, Tai Duc Nguyen +5
Singapore Management University · Max Planck Institute · Technical University Braunschweig
We present EmbodiedGen V2, a generative 3D world engine for building executable policy-ready environments for embodied intelligence. Sim-ready 3D asset generation has advanced rapidly, yet assembling such assets into policy-ready task environments remains largely manual, limiting scalable closed-loop learning. EmbodiedGen V2 addresses this gap through a unified sim-ready representation that connects cross-simulator assets, interaction affordances, task-driven worlds, large-scale multi-room scenes, and stateful Vibe Coding into a generative, editable, and reusable simulation pipeline. The generated environments support manipulation, navigation, mobile manipulation, cross-simulator deployment, and embodied policy training. In evaluation, the asset pipeline achieves 96.5% human acceptance and 98.6% collision success, and 83.3% of task-driven worlds are directly usable for downstream simulation without manual modification. Online reinforcement learning with generated environments further improves simulation success from 9.7% to 79.8%, and transfers to real robots with task success increasing from 21.7% to 75.0%. These results establish EmbodiedGen V2 as scalable simulation infrastructure for training, evaluating, and deploying embodied policies.