Preserved
- Existing triangle surfaces are preserved without repair or added detail.
- Triangle connectivity is retained; no quad reconstruction or automatic welding is performed.
From a print package to editable objects
3MF to OBJ Converter Online
Open the mesh geometry inside a 3MF package in an OBJ-compatible editor. Inspect build items, preserve their placement, and choose one OBJ with named objects, a merged mesh or separate files. Print settings, colors and texture data stay in the original 3MF project.
Drop 3MF file here
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Max 100 MB · processed locally
Your model stays on this device. Parsing, conversion, verification, and download preparation run locally in this browser.
What the conversion keeps and removes
Converted
- Keep retains detected build items as named objects. Nested components and instancing relationships are flattened; disconnected shells are not split automatically.
- Build and component placement is baked into vertices before merging or splitting.
- 3MF physical dimensions become the selected numeric coordinates. OBJ carries no unit label.
- Z-up is defined by 3MF; choose the OBJ orientation for your editor.
- OBJ normals are calculated from the triangle surfaces; original CAD surface normals cannot be recovered.
Lost
- 3MF texture UVs are omitted by this geometry-only route.
- Per-face and per-vertex colors are lost.
- Materials and material assignments are lost; no MTL library is produced.
- Texture images are omitted. External package dependencies must be embedded or removed before upload.
- Manufacturing metadata, custom properties and production relationships are lost. Required extensions and cross-file component references are rejected.
- Printer profiles, layer settings, paint assignments and support metadata are lost; support geometry already modeled as triangles remains geometry.
Unsupported input
- Cameras and lights are not reconstructed.
- Only static build geometry is supported; motion is not reconstructed.
- Exact CAD curves, surfaces and feature history cannot be reconstructed.
How do I extract OBJ geometry from a 3MF project?
Choose a self-contained core 3MF file, inspect its build items and convert their existing triangles to OBJ. Component and build transforms are baked into vertex positions, so parts retain their relative placement. The source unit is read from the model, with millimeters as the specification default. This workflow is useful for mesh editing and geometry interchange; it does not transfer a complete slicer project into OBJ.
- Local 3MF package parsing
- Declared units and Z-up
- Baked build placement
- Keep, merge or split build items
- Mirrored face correction
- Verified OBJ and ZIP downloads
What the OBJ takes from the 3MF package
Build placement becomes vertex positions
The converter resolves build and nested component transforms. Mirrored objects receive corrected triangle winding. Keep retains build items as flat named objects; the component tree is not carried into OBJ.
Physical dimensions become unitless coordinates
3MF declares its model unit and uses Z-up. Select the intended OBJ unit and orientation; scaling and rotation are applied once. Use the same unit when importing the result in another application.
Manufacturing appearance is omitted
This route imports geometry without loading texture images. Colors, texture coordinates, material groups, slicer paint assignments and printer settings are omitted. OBJ normals are calculated from the mesh faces.
How to extract OBJ from 3MF
Step 1
Open a core 3MF package
Select a .3mf file up to 100 MB and inspect its parsed build geometry, dimensions and triangle count.
Step 2
Choose OBJ coordinates and build-item handling
Review the detected 3MF unit and Z-up orientation. Select the output unit and axis, then keep, merge or split multiple build items.
Step 3
Inspect the verified output and download
Convert, compare the independently reparsed OBJ preview and dimensions, then download one OBJ or a ZIP. Retain the 3MF for printing settings and appearance.
Use print geometry outside the slicer
Edit a printable model as polygons
Extract an OBJ for sculpting, cleanup or retopology when the destination editor does not accept 3MF packages.
Separate build items for an asset workflow
Split detected build items into individual OBJ files while preserving their positions. Multiple downloads are packaged into one ZIP with unique filenames.
Combine a layout for geometry inspection
Merge the placed build items into one named mesh for a downstream tool that expects a single object. Overlapping pieces remain overlapping surfaces.
3MF and OBJ are different file formats
3MF is a package format for additive manufacturing. Alongside triangle geometry, it can contain build placement, units, material properties and application-specific print data. OBJ is a text geometry format used by modeling tools. This converter extracts the mesh portion of a supported 3MF, so it is a geometry handoff rather than a portable copy of the complete print project.
| Property | 3MF | OBJ |
|---|---|---|
| Mesh geometry | Indexed triangle meshes | Triangle faces and calculated normals |
| Build structure | Build items and component trees | Flat named objects or separate files |
| Placement | Build and component transforms | Transforms baked into vertices |
| Coordinates | Declared unit; Z-up | Selected coordinates without unit metadata |
| Appearance | Colors, material groups and texture extensions | No colors, UVs, MTL or images in this route |
| Print project | Printer profiles and manufacturing metadata | Geometry only; retain the original project |
Resolve 3MF package problems
- A required extension is unsupported
- Export a core 3MF mesh from the source application. Production, beam, slice or other required extensions must be resolved by an application that understands them.
- The project has invalid geometry or references
- Repair invalid vertices, triangle indices or transforms, then export a self-contained core 3MF. Missing or external companion data is not fetched.
- The result has no colors or printing setup
- That data is outside this geometry export. Keep the original 3MF for its materials, textures, support instructions and slicer profiles; assign OBJ materials separately.
3MF to OBJ limitations
- 3MF to OBJ loses colors, materials, texture UVs and images, slicer settings, supports metadata and manufacturing data. No MTL file is generated. OBJ stores no physical unit; keep the 3MF project for printing.
- Only supported core triangle meshes are converted. Required extensions and external package dependencies need a self-contained core export first.
- Split operates on detected build items, not every disconnected shell or nested component.
- No automatic repair, Boolean union, solid reconstruction or extra surface detail is added. Support objects already present as triangle geometry remain geometry.
3MF to OBJ FAQ
What is lost when I convert 3MF to OBJ?
3MF to OBJ loses colors, materials, texture UVs and images, slicer settings, supports metadata and manufacturing data. No MTL file is generated. OBJ stores no physical unit; keep the 3MF project for printing.
Does a 3MF project become one OBJ object?
Keep source structure creates one named OBJ object per detected build item. Merge creates one object, while Split creates one file per build item. Nested component hierarchy is flattened in every mode.
Are the model size and build placement retained?
Yes, for supported geometry. Build and component transforms are baked, then your selected scale and orientation are applied once. OBJ has no unit declaration, so import it with the selected output unit.
Can I convert every slicer 3MF project?
Files must contain supported core mesh geometry. Required extensions or external dependencies are rejected with a recovery message. Re-export a self-contained core 3MF from the original application when needed.
Will the OBJ include UVs and MTL materials?
No. This 3MF route extracts geometry and calculated normals; it omits texture coordinates, colors, images and material libraries.
Is my 3MF uploaded?
No. Archive reading, geometry parsing, previews, export, validation and ZIP packaging run locally in the browser.
Need a triangle file for a slicer instead?
Use the homepage 3MF to STL converter when your destination is a slicer that expects STL facets. Choose OBJ here when named objects and mesh editing are the next step.