IsItPrintable

Format conversion/CAD → mesh

STEP / IGES / BREP to mesh (local)

Tessellate STEP, IGES, or BREP into STL, OBJ, PLY, 3MF, GLB, or glTF locally with the OCCT WASM kernel, export a hierarchy-aware GLB assembly with face colors, or download each OCCT mesh as a separate STL in a ZIP. The B-rep file is read in the Worker and never uploaded.

ReadyNo uploadWorkerSTEP · IGES · BREP

CAD import report

No upload

CAD import report

The CAD file is parsed by a local OCCT WASM kernel. The file, tessellation and output stay in the Worker and this tab.

Drop a STEP, IGES, or BREP file

STEP, IGES, or BREP. The local OCCT WASM kernel tessellates the B-rep; choose the output mesh format below.

STEP · STP · IGES · IGS · BREP

Drop a STEP, IGES, or BREP file

STEP, IGES, or BREP. The local OCCT WASM kernel tessellates the B-rep; choose the output mesh format below.

Choose a file

Max file size: 100 MB · No upload

Changing the output format re-runs tessellation and conversion.

No upload · OCCT WASM → Worker → mesh download.

How it works

  1. 1

    Drop a STEP (.step/.stp), IGES (.iges/.igs), or BREP file.

  2. 2

    Choose a single mesh format (STL, OBJ, PLY, 3MF, GLB, or glTF), the GLB assembly output that keeps hierarchy and face colors, or the STL parts ZIP output.

  3. 3

    The Worker loads the local OCCT WASM kernel and tessellates the B-rep surfaces.

  4. 4

    Mesh outputs flatten the OCCT meshes into one indexed mesh. The GLB assembly output writes one glTF node per OCCT hierarchy node and turns each face color into a material. The STL parts ZIP writes each OCCT mesh as its own file, preserving part separation but not hierarchy or colors.

  5. 5

    Download the converted mesh. Changing the output format re-runs tessellation in the Worker.

What the numbers mean

Tessellation

OCCT tessellates curved faces into triangles. This build uses a 0.1% bounding-box linear deflection and a 0.5 radian angular deflection. The result is a faceted approximation of the exact B-rep, not the original surface.

Assembly handling

STEP and IGES assemblies can contain multiple solids. Mesh formats merge them into a single triangle mesh. The GLB assembly output keeps the OCCT node hierarchy, part names, normals and per-face colors, with one glTF material per color. The STL parts ZIP keeps each OCCT mesh separate and uses its name when available, but does not keep hierarchy or colors.

Units

STEP and IGES are tessellated in millimetres. BREP carries no unit metadata, so its coordinates are treated as millimetres. Check the model scale before printing.

CAD formats

STEP (AP203/AP214 and related schemas), IGES and BREP are B-rep formats. They are imported one way into mesh formats; this tool does not write STEP, IGES or BREP.

Limits

The CAD file limit is 100 MB. Tessellation can be memory-intensive for large assemblies; use a smaller assembly or export a simplified solid if the browser runs out of memory.

Printing notes

  • Check the imported bounds against the expected CAD dimensions before slicing.
  • Tessellated curved surfaces are faceted; increase quality in CAD or re-export a finer B-rep if the facets affect fit.
  • Run manifold-check after import if the CAD tessellation has open faces or non-manifold edges.
  • Use transform-mesh to scale, center, or place the result on the bed after import.
  • Use the GLB assembly output when a viewer needs the assembly hierarchy and face colors. Use the STL parts ZIP when you need separate printable parts; the ZIP keeps names but not colors.

Questions

References

  • · ISO 10303 (STEP)
  • · IGES 5.3
  • · Open CASCADE Technology tessellation