Hi everyone,
I’ve been frustrated for years that Blender can’t open STEP files out of the box. The few free options either require a manual pip install of OpenCascade bindings (which most artists understandably don’t want to do), or produce broken meshes with missing faces. So I built my own.
STEP Importer is a paid Blender extension that ships as a single zip with all the OpenCascade libraries bundled inside. Drop it into Edit → Preferences → Get Extensions → Install from Disk and you’re done. No terminal, no pip, no setup. Works on Windows, macOS (Intel + Apple Silicon), and Linux (x64 + ARM64).
Key features:
- Full assembly support — preserves the STEP hierarchy as nested collections, flat collections, or parented Empties. Instances share mesh data automatically.
- Per-shape colors read from the STEP file, exposed as proper material slots or a vertex color layer
- Four quality presets (Preview / Standard / High / Ultra) plus full Custom control over deflection, sharp-edge threshold, weighted normals
- Parallel pre-tessellation — meshes all shapes in one multi-core OpenCascade pass. Significant speedup on big assemblies
- Origin-to-geometry on import (instance-safe), so rotating individual parts in Blender actually behaves
- File analyzer that shows shape/face/edge counts, bounding box, and per-preset import-time estimates calibrated to your hardware — before you commit to the import
- Rebuild Selected: re-tessellate already-imported objects with new quality settings without re-reading the file
- Adaptive deflection that scales per face — handles parts of wildly different sizes in the same model (think bolts in a building)
- Modal import with ESC-cancel, proper progress display, custom split normals, UV layer from surface parametrisation, up-axis swap, unit detection — the polish items you’d expect
Supports .step, .stp, AP203/214/242 (whatever the OpenCascade kernel handles).
Available on Gumroad: https://rookiecgi.gumroad.com/l/STEPimporter
Would love feedback — happy to add features or fix issues based on what you all actually need.
Cheers
