File formats

This page follows the format sheet inside the app. Open it there with Compare in the Export window.

Formats it opens

STEP (.step, .stp)

The CAD exchange format. Converted by the local Python converter. Keeps the parts tree and materials. Open only: the app does not write STEP.

IGES (.iges, .igs)

An older CAD exchange format, often a surface model. Converted by the local Python converter. Keeps the names, colours and layers the file has, but not an assembly tree. Open only.

BREP (.brep, .brp)

The OpenCascade shape format. Converted by the local Python converter. Geometry only. Open only.

GLB

Binary glTF. Keeps the parts tree, full materials and vertex colours. The best all-round format.

glTF

The text form of GLB. The same capabilities, larger.

FBX

A common exchange format between 3D programs, Blender among them. Keeps the parts tree and materials.

OBJ

Universal, but with no transforms and no tree. Materials come from a separate .mtl file.

3MF

A 3D-printing format. Keeps the parts tree and materials. Open only.

STL

Geometry only, as a single mesh. Used for 3D printing.

STEP, IGES and BREP files go through the converter. The others load directly in the browser.

Formats it writes

GLB

Parts tree, full materials, vertex colours. Optional Draco or Meshopt compression.

glTF

The same as GLB, as text.

FBX

Parts tree and materials. Binary FBX 7.4 by default, with a text (ASCII) version as a fallback.

USDZ

Parts tree and materials. For Apple Quick Look and Reality Composer. Write only.

OBJ

A flat list of parts, with the hierarchy folded into their names. Materials in a .mtl file.

STL

One mesh, geometry only.

PLY

One mesh, with a colour for every vertex. Write only.

CSV

A parts list. No geometry. Write only.

The three columns of the sheet

Hierarchy

Whether the format keeps the parts tree: groups, and groups inside groups.

Materials

Colour and shading for each part. “PBR” means the full set with metalness and roughness. A plain dot means colour only.

Vertex colours

A colour stored on every corner point of the mesh, with no separate material.