Open world models for worldbuilding (Oct 2026): persistent 3D worlds (HY-World 2.0) vs memory-based video worlds (WorldCrafter) vs keyboard-controlled video (H3-World)

Three open releases with different output types. (1) HY-World 2.0 (Tencent; card updated May 2026; ~720 likes): text, single image, multi-view images or video -> persistent 3D worlds as meshes / 3D Gaussian splats via panorama generation (HY-Pano 2.0) -> trajectory planning (WorldNav) -> world expansion (WorldStereo 2.0) -> composition (WorldMirror 2.0 + 3DGS); WorldMirror 2.0 (~1.2B) reconstructs depth, normals, cameras, point clouds and 3DGS from photos/video in one forward pass; outputs import into Blender/Unity/Unreal/Isaac and support first/third-person exploration with collision. The card argues 3D outputs beat video world models on persistence, consistency and per-interaction cost (vendor framing). LICENCE: Tencent HY-World 2.0 Community License does not apply in the EU, UK or South Korea, forbids using the works OR THEIR OUTPUT outside the Territory, and requires a separate licence above 1M MAU; HF gating marks EU disallowed. (2) WorldCrafter (TencentARC; arXiv 2609.24984, 2026-09-21; Base and Fast weights in diffusers format): a video world model with a camera-queryable implicit 3D-aware memory - historical views compressed into target-view tokens before denoising - plus few-step distillation for streaming exploration from one image or prompt; reports better long-horizon consistency and camera-control accuracy over minute-scale exploration. Licence not declared on the card or repo (NOASSERTION) - treat as unlicensed until clarified. (3) H3-World (arXiv 2609.01560): a 65.6M-parameter LoRA (0.199% of the 33B MiniMax-H3 backbone) trained on 8,000 gameplay clips; WASD moves the character, IJKL the camera, F = fast camera; keyboard states become one language instruction per future latent with directed attention routing; needs the official patch; checkpoint is a MiniMax-H3 Model Derivative under the H3 Community Licence (territory exclusions, see C3-B364/B372), code Apache-2.0. Worldbuilding implication: for reusable sets prefer persistent 3D (splats/meshes) as in C3-B393-03 Blender previs; video world models suit exploration/previz but not yet persistent canon. Nothing was run. Curator correction 2026-10-24 (discovery audit record C3-B1036-01, curator-reviewed C3R-0686; excerpts re-located by independent curator GET 2026-10-24): Correction. C3-B399-01 said the WorldCrafter licence was 'not declared on the card or repo (NOASSERTION) - treat as unlicensed until clarified'. That was wrong as written: the repository root has LICENSE.txt, first committed 2026-09-19 (commit feed; before the 2026-09-21 arXiv date the record cites), and the README says 'See [LICENSE.txt](LICENSE.txt) for the terms of use and third-party attributions.' The GitHub licence-detection field is NOASSERTION, probably because the file is not a standard SPDX licence (inference). As of 2026-10-24 LICENSE.txt has two separate parts. (1) First-party terms: an MIT-style grant ('Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files') followed by the condition 'You agree to use the WorldCrafter only for academic purposes, and refrain from using it for any commercial or production purposes under any circumstances.' So the first-party licence is not plain permissive: it limits use to academic, noncommercial purposes. (2) Bundled third-party components under their own terms: Helios-Base (Apache-2.0), VGGT (CC-BY-NC-4.0) and, added 2026-09-22, LagerNVS under the FAIR Noncommercial Research License, whose text says 'You will not use the Research Materials or any outputs or results of the Research Materials in connection with any commercial uses'. Hugging Face model metadata for WorldCrafter-Base lists no licence tag. Not legal advice; read the file before relying on it. Curator qualifications: Some cited evidence could not be re-located by curator GET (see mechanical_checks); no video sources. Model cards/repos as served; likes/popularity are not validation; licences per model card. Limitations: Vendor/author claims; no runs; WorldCrafter licence unknown; HY-World MAU threshold measured at release date. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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  "citations": [
    {
      "url": "https://github.com/Tencent-Hunyuan/HY-World-2.0/blob/main/License.txt",
      "note": "line 3; Section 5c; abstract; card"
    },
    {
      "url": "https://arxiv.org/abs/2609.24984v1",
      "note": "line 3; Section 5c; abstract; card"
    },
    {
      "url": "https://huggingface.co/DANNY621/H3-World",
      "note": "line 3; Section 5c; abstract; card"
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