Download

GLB is produced when a submission completes. Other formats are converted on-demand: either inline via the unified /download endpoint (which waits for the result), or asynchronously via the /convert job API.

Download a submission asset

GET /api/v1/{submission_id}/download

Public.

Unified endpoint for all downloadable artifacts. GLB is always ready; FBX/OBJ/STL/USDZ trigger an on-demand conversion if not yet cached.

Path Parameters

Name	Type	Description
`submission_id`	string (required)	UUID of the submission.

Query Parameters

Name	Type	Description
`format`	string	Asset format. Values: `glb`, `fbx`, `obj`, `stl`, `usdz`, `py`, `thumbnail`, `reference_image`. Default: `glb`.
`textures`	string	GLB only. `png` (default) or `webp`.
`draco`	boolean	GLB only. Draco geometry compression. Default: `false`.
`index`	integer	Index for `reference_image` format (0–5). Default: `0`.

Example Request

# GLB (instant)
curl -L -o model.glb \
  "https://api.thrixel.com/api/v1/a1b2c3d4-.../download?format=glb"
 
# FBX (triggers conversion, may take a few seconds)
curl -L -o model.fbx \
  "https://api.thrixel.com/api/v1/a1b2c3d4-.../download?format=fbx"

Shipping a GLB to a browser

If the model is going into a web page or a browser game, ask for WebP textures:

curl -L -o model.glb \
  "https://api.thrixel.com/api/v1/a1b2c3d4-.../download?format=glb&textures=webp"

Measured at export on real submissions:

Model	Default (png)	`textures=webp`	`+ draco=true`
Geometry-heavy (15% textures)	7.00 MB	6.28 MB	1.18 MB
Texture-heavy (100% textures)	18.33 MB	0.95 MB	0.91 MB

Textures are where most of the weight is on most models, and WebP is a plain image format the browser decodes natively - nothing extra to install, and a reader that cannot handle it fails visibly. This is the setting to reach for first. Thrixel's own web viewer serves exactly this: textures=webp, no Draco.

When to add Draco

draco=true compresses the geometry rather than the textures, so it only pays off on models that are mostly geometry - the first row above, where it turns 6.28 MB into 1.18 MB. On a texture-heavy model it buys about 4%.

Draco needs a decoder on the other end

KHR_draco_mesh_compression is read by three.js (with DRACOLoader), Babylon, model-viewer and Blender 4.x, but three.js fetches a ~200KB WASM decoder at runtime and you have to wire it up. A reader without a Draco decoder usually does not raise an error - it returns the mesh with every vertex at the origin. Do not hand a Draco file to an unknown tool, and do not feed one back into a pipeline of your own.

Both flags are independent, and neither changes the model: same parts, same triangle count, same bounds.