
HI3D v2.1 Fast API by HI3D
HI3D v2.1 Fast turns one photo — or two to four views of the same object — into a textured 3D mesh at 1536³ resolution. The quickest and cheapest tier in the HI3D line, built on Math Magic's Sparc3D geometry model, with PBR textures and GLB/OBJ/STL/FBX/USDZ/3MF output.
HI3D v2.1 Fast is developed by a third-party provider. Atlas Cloud (operated by Atlas Cloud AI LLC) provides access to it and does not own it. All trademarks belong to their respective owners.
HI3D v2.1 Fast
HI3D v2.1 Fast turns a photograph into a textured 3D mesh at 1536³ resolution. It is the entry tier of the HI3D line — the same Sparc3D geometry model as v2.1 Pro, with a shorter refinement pass. Generation is asynchronous; results are re-hosted on AtlasCloud storage.
Why Choose This?
- Fastest turnaround in the line — the shortest refinement pass of the four tiers.
- Up to four views — add back, left and right shots and the sides follow your reference instead of being inferred.
- PBR out of the box — base colour plus metallic, roughness and normal maps unless you turn them off.
- Six export formats — GLB, OBJ, STL, FBX, USDZ and 3MF from the same request.
- Geometry-only mode —
should_texture: falsewhen you only need the mesh.
Parameters
| Parameter | Required | Description |
|---|---|---|
model | Yes | hi3d/v2.1-fast/image-to-3d |
image | Yes | Source image: public URL or base64 data URI. png/jpg/jpeg/webp, up to 20 MB. |
reference_images | No | Up to three more views of the same object, for four in total. |
multi_images_bit | No | Which view slots the images fill, as four 0/1 characters (front, back, left, right). Defaults to the leading slots. |
should_texture | No | Generate textures as well as geometry. Default: true |
enable_pbr | No | Also produce metallic / roughness / normal maps. Default: true. Requires should_texture. |
shading | No | De-lighting strength, 0.0–1.0. Default: 0.5. Requires should_texture. |
rmbg | No | Remove the input image's background before reconstruction. Default: true |
target_polycount | No | Face count, 100000–5000000. Omit to let HI3D pick; recommended here: 2,000,000. |
output_format | No | glb (default), obj, stl, fbx, usdz, 3mf. |
Resolution is fixed at 1536³ Fast for this model and is not a request parameter — each HI3D tier is its own model. To change resolution, call a different model.
How to Use
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateImage" \ -H "Authorization: Bearer $AIP_API_KEY" \ -H "Content-Type: application/json" \ --data-raw '{ "model": "hi3d/v2.1-fast/image-to-3d", "image": "https://static.atlascloud.ai/media/images/sneaker.png", "should_texture": true, "enable_pbr": true, "output_format": "glb" }'
Multi-view, four photographs of the same object:
curl -X POST "https://api.atlascloud.ai/api/v1/model/generateImage" \ -H "Authorization: Bearer $AIP_API_KEY" \ -H "Content-Type: application/json" \ --data-raw '{ "model": "hi3d/v2.1-fast/image-to-3d", "image": "https://static.atlascloud.ai/media/images/sneaker_front.png", "reference_images": [ "https://static.atlascloud.ai/media/images/sneaker_back.png", "https://static.atlascloud.ai/media/images/sneaker_left.png", "https://static.atlascloud.ai/media/images/sneaker_right.png" ] }'
Generation is asynchronous — poll /api/v1/model/prediction/{request_id} until status is completed, then read the model URL from outputs. files gives the same URLs with their format and MIME type, and thumbnail is a rendered preview. Expect about 7-10 minutes.
Best Use Cases
- Bulk catalogue conversion — thousands of product shots where throughput matters more than micro-detail.
- Previz and blockout — a real mesh in minutes to judge scale and silhouette before committing to a hero asset.
- Iterating on inputs — try several photos here, then re-run the winner on v3.0 Quality.
- AR viewers — USDZ straight from a single product shot.
Pro Tips
- One object, centred, evenly lit, plain background. Clutter and hard shadows are reconstructed as geometry.
- A three-quarter view reconstructs better than a dead-on front or a steep top-down shot.
- Shooting the back and sides and passing them as
reference_imagesis the single biggest quality lever — bigger than moving up a tier. - Leave
rmbgon unless your image is already cut out against transparency. - Raise
shadingwhen the source photo has strong directional light you do not want baked into the texture; lower it when the lighting is already flat. should_texture: falsereturns the bare mesh sooner — use it when you are going to texture the model yourself.
Notes
- Accepted input formats are png, jpg, jpeg and webp, up to 20 MB each.
reference_imagesmust be views of the same object. Different objects produce a fused, unusable mesh.multi_images_bitmust contain exactly as many 1s as there are images in total (imageplusreference_images); a mismatch is rejected before the request reaches HI3D.enable_pbrandshadingonly apply whenshould_textureis on; they are dropped otherwise.- HI3D's own result links expire one hour after generation. The URLs returned here are AtlasCloud-hosted and stay reachable.
Related Models
- HI3D v2.1 Pro — 1536³ Pro.
- HI3D v3.0 Quality — 2048³ Quality.
- HI3D v3.0 Master — 2048³ Master.


















