Wavefront OBJ

Reference

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File ‣ Import/Export ‣ Wavefront (.obj)

OBJ is a widely used de facto standard in the 3D industry. The OBJ format is a popular plain text format, however, it has only basic geometry and material support.

Note

There is no support for armatures, lights, cameras, empty objects, parenting, or transformations. See Compatibility for more information.

Usage

Export geometry and curves to the OBJ format.

Exporting

Properties

Animatioon

Animation

Exports a numbered OBJ for each frame from the start to the end frame. Please be aware that this can take quite a long time.

Frame Start, End

The first and last frame to export, used to determine the range of exported frames.

Object Properties

Axis Forward, Up

Since many applications use a different axis for ‘Up’, there are axis conversion settings, Forward and Up axis – By mapping these to different axis you can convert rotations between applications default up and forward axis.

Blender uses Y Forward, Z Up (since the front view looks along the +Y direction). For example, its common for applications to use Y as the up axis, in that case -Z Forward, Y Up is needed.

Scale

Global scale to use on export.

Selected Only

Only export the selected objects. Otherwise export all objects in the scene.

Properties

For properties that have different settings for the viewport/final render pick which is used for output. One example where this is important is the Subdivision Surface Modifier.

Viewport (Default)

Use viewport properties.

Render

Use final render properties.

Geometry Export

UV Coordinates

Write out the active UV layers coordinates from Blender.

Normals

Write out Blender’s face and vertex normals (depending on the faces smooth setting).

Mostly this isn’t needed since most applications will calculate their own normals but to match Blender’s normal map textures you will need to write these too.

Materials

Write out the MTL-file along with the OBJ. Most importers that support OBJ will also read the MTL-file.

Triangulated Mesh

Write out quads as two triangles. Some programs only have very basic OBJ support and only support triangles.

Curves as NURBS

Write out NURBS curves as OBJ NURBS rather than converting to geometry.

Grouping

Object Groups

Write out each Blender object as an OBJ object.

Note

Note that as far as Blender is concerned there is no difference between OBJ Groups and Objects, this option is only included for applications that treat them differently.

Material Groups

Create OBJ groups per material.

Vertex Groups

Export the name of the vertex group of a face. It is approximated by choosing the vertex group with the most members among the vertices of a face.

Smooth Groups

Write Blender’s sharp edges as smooth groups.

Bitflag Groups

Generate Bitflags for smooth Groups.

Importing

Importing OBJ-files is currently handled by a python importer which is included as an addon. It’s documentation can be found here: OBJ Importer </addons/import_export/scene_obj>.

Compatibility

NURBS surfaces, text3D and metaballs are converted to meshes at export time.