Issues Importing DJI Terra 3D Models into CesiumJS/Cesium Ion

Cesium ion
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Dear Cesium Team and Community,

I hope this message finds you well. I am reaching out to seek guidance regarding persistent challenges I have encountered when importing 3D models exported from DJI Terra into CesiumJS and Cesium Ion. Despite attempting multiple formats (OBJ, FBX, B3DM, PLY), these issues remain particularly noticeable at larger scales.

Summary of Issues:

1. Low-detail LOD in B3DM tiles

  • DJI Terra B3DM exports often appear blurry or washed-out initially.

  • Root tiles contain high geometric error by design; finer detail only appears upon zooming.

  • Challenge: CesiumJS’s default maximumScreenSpaceError can result in very coarse previews.

  • Temporary Workaround: Reducing maximumScreenSpaceError (e.g., 1–2) improves LOD detail, though textures and finer geometry occasionally remain suboptimal.

2. Upload and Format Constraints in Cesium Ion

  • Terra exports multi-block OBJs with textures and metadata XML, which Cesium Ion’s 3D Tiles importer does not support.

  • Challenge: Uploading multiple OBJs or zipping Terra folders can result in blank models or failed uploads.

  • Potential Workarounds:

    • Merge OBJs into a single model and upload under “3D Model (Capture)” for Ion to generate tiles.

    • Export the full 3D Tiles folder (tileset.json + B3DM files) as a ZIP and upload under “3D Tiles.”

3. Large Model Crashes and Scaling Limitations

  • Loading multiple OBJs simultaneously can exceed memory/GPU limits, causing CesiumJS or Ion to crash.

  • Observation: 1–2 OBJs typically load successfully; larger sets often fail.

4. General Reliability at Scale

  • Users consistently report issues with multi-block or large-scale Terra exports.

  • Even with correct export formats, additional LOD or error-tolerance adjustments are often required for reliable rendering.

These challenges make large-scale DJI Terra → Cesium workflows unpredictable. I would greatly appreciate any advice, guidance, or recommended solutions from the Cesium team or community to improve reliability when handling large DJI Terra models. Additionally, any insights on whether some of these issues (such as tile validation errors or large-scale crashes) can be addressed within CesiumJS/Ion, or if workarounds are the only viable approach, would be highly valuable. We have tried as many file formats and export strategies as possible but have yet to find a reliable solution. Any recommendations from the Cesium team would be greatly appreciated.

Thank you very much for your time and assistance. I look forward to your insights.

Kind regards,
Alex