Checking the preview before you upload

Checking the preview before you upload

The wizard's Preview step loads your tileset in a real 3D viewer and lines your images up against it. This is the last point at which fixing a bad export costs you minutes rather than a full re-upload.

The Preview step showing the tileset loaded in the 3D viewer

What to look for

Does the model look right? Complete, correctly oriented, nothing missing.

Do the images line up? Pick a camera position and check that the image matches what the model shows from that spot. If images are consistently offset, the camera metadata does not match the tileset. That is usually a mismatched export, where the metadata and the model came from different processing runs.

Messages you might see

None of these stop you uploading. They tell you what the preview found.

Message What it means
No tileset JSON file found at archive root The preview could not find a 3D Tiles root file to show. The upload itself looks deeper into the archive, so this often still works.
Multiple JSON files found at archive root Several JSON files sit at the top level. The upload picks the right one for you.
Tile file for the tileset was not found The archive is missing .b3dm files it references. Missing tiles mean a missing model, so re-export.
A misalignment warning Images and model do not line up. Investigate before uploading: see below.

If the preview will not render your model but you believe the export is sound, you can continue. Check the finished project afterwards; if the model is missing there too, re-export.

How your zip is read

You do not need to arrange the archive in a particular way. On upload, Twinsity looks through it for the 3D Tiles root file, the JSON describing your model, then works out the structure from there:

  • The root file can be called anything. MyModel.json is as good as tileset.json; it is renamed for you.
  • It can sit inside a subfolder. If your export produced MyModel/tileset.json, that is handled. The extra folder level is stripped for you.
  • Several JSON files at the top are fine. Each is checked, and the real 3D Tiles root is the one used.

One thing is genuinely not supported: tilesets using implicit tiling. Those are skipped, so if a model will not load at all, check whether your export used it.

If images and model do not align

Usually one of:

  • Metadata and tileset from different runs. Re-export both from the same processing result.
  • The wrong coordinate system. Check your export guide. Most tools want WGS 84 (EPSG:4326).
  • RealityScan with local coordinates. Not supported. Re-export geo-referenced.
  • Tie points included. DJI Terra needs them disabled during preprocessing.

The quality slider

While the preview loads you can trade detail against speed. It affects this preview only. The uploaded project is unchanged, and so is what anyone sees later.

Next step

If the model looks right and the images line up, continue to the upload. See Uploading, pausing and resuming.

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