Free online OBJ to SCAD converter

OBJ files are commonly supplied by 3D modeling and scanning software, while OpenSCAD requires a script-based .scad file. Converting the mesh is useful when an OBJ model must be included in an OpenSCAD project, parameterized alongside other geometry, or archived as a reproducible model definition.

What the OBJ format is

OBJ is a plain-text polygon-mesh format that stores vertex coordinates, faces, normals, and optional texture coordinates. Material assignments are usually stored in a separate .mtl file, with image textures referenced by that material file.

Blender, Maya, 3ds Max, MeshLab, CAD applications, photogrammetry tools, and 3D scanners commonly create or export OBJ files. You may encounter OBJ when downloading model assets, exchanging meshes between applications, or processing scanned objects.

What the SCAD format is

SCAD is the source format used by OpenSCAD. It contains text commands such as cube(), cylinder(), union(), and difference(), so dimensions and construction steps can be edited directly.

An OBJ mesh cannot normally be translated into equivalent OpenSCAD primitives automatically. The practical result is usually a SCAD file that imports a converted STL or OFF mesh. This preserves the shape but does not make the original surface editable as cylinders, cubes, or other parametric features.

How to convert OBJ to SCAD

Using Blender and OpenSCAD

1. Open Blender and choose File → Import → Wavefront (.obj). Keep the accompanying .mtl file and texture images beside the OBJ if you need to inspect materials.
2. Select the imported object, apply its transform with Object → Apply → All transforms, and check its dimensions in the Item panel. Remove cameras, lights, and unwanted mesh objects.
3. Export the geometry through File → Export → STL. Enable selection-only export when appropriate. Use millimeters consistently; STL does not store units.
4. Create a plain-text file named model.scad in the same directory as the STL, containing:

import("model.stl");

Open model.scad in OpenSCAD and press F6 to render the imported mesh. Save the SCAD source file; it references model.stl, so keep both files together when sharing or archiving the project.

For a scale correction, apply a factor before importing, for example:

scale([25.4, 25.4, 25.4]) import("model.stl");

Use this only when the exported dimensions are in inches and the OpenSCAD project requires millimeters. Confirm the result against a known measurement rather than assuming the unit system.

Using the online converter

You can convert the file on 101convert.com for free without installing software. Upload the OBJ, choose SCAD as the output format, start the conversion, and download the generated file. Inspect the resulting source and verify the scale, because automated conversions commonly produce an import wrapper rather than native OpenSCAD modeling operations.

Quality, compatibility, and limitations

• The OBJ material, color, and texture data generally do not survive an STL-based workflow. The SCAD file controls geometry, not OBJ visual materials.
• OpenSCAD may report warnings or render incorrectly if the mesh has holes, self-intersections, duplicate faces, reversed normals, or non-manifold edges. Repair the mesh in Blender, MeshLab, or another mesh editor before export.
• Large or highly detailed meshes can make OpenSCAD preview and rendering slow. Decimate the mesh in Blender when geometric detail exceeds the required manufacturing or visualization resolution.
• The generated SCAD is not a parametric reconstruction. To obtain editable dimensions and Boolean features, remodel the object with OpenSCAD primitives or use the imported mesh only as a reference.
• For 3D printing, validate the final mesh in a slicer after OpenSCAD rendering and export. OpenSCAD can render a visually plausible model that still contains invalid solid geometry.