OBJ (.obj) import/export

The OBJ file format is a simple data-format that represents 3-D geometry alone include only the position of each vertex, the UV position of each texture coordinate vertex, normals, and the faces that make each polygon defined as a list of vertices, and texture vertices. Vertices are stored in a counter-clockwise order by default, making explicit declaration of normals unnecessary.


To open, import, insert, and attach a file as a worksession

  1. From the File menu, click Open, Insert, Import, or Worksession > Attach.

  2. In the dialog box, select a supported file type.
  3. Click Open and configure the settings.
    When you open a non-3dm file and save the model, its filename will be the default 3dm filename.

OBJ Import Options

Import OBJ groups as

Object names
Import OBJ objects
Import as morph target only
Reverse group order
Ignore textures

Set display color from OBJ material color

Enable to import material colors in the OBJ file as object display colors. Otherwise, the default color is used.

Map OBJ Y to Rhino Z
Split 32-bit textures into separate files
Always use these settings. Do not show this dialog again.

Saves the current settings and turns off the dialog display.

To turn the message back on

See also: ResetMessageBoxes command.


To save as or export a Rhino model

  1. On the File menu, click Export Selected or Save As.
  2. In the dialog box, the Files of type list displays the currently supported file types for export.
  3. In the Files of type box, select the supported file type.
  4. In the File name box, select or type a file name.
  5. Specify what is to be saved.
  6. Options

    Save small

    Though clearing the render meshes makes the file smaller, it will shade and render more slowly the next time you open the file.

    Save geometry only

    Saves geometry objects only. No layers, materials, properties, notes, or units settings are saved. This is similar to exporting the objects. A new file is made, but it does not become your active Rhino model.

    Save textures

    Embeds external textures used by materials, environments and decals into the model.

    Save plugin data Saves data attached to objects or the document by plug-in applications.
  7. If the export can be configured, click the Options button to specify export settings.
  8. Mesh file types export NURBS surfaces as meshes either with the specified meshing options, or the document render mesh settings.

OBJ Export Options


Save surfaces, polysurfaces and extrusions as

NURBS objects

Rhino curves and surfaces export as NURBS curves and surfaces.

Polygon mesh objects

Surfaces are approximated with polygon mesh objects. In the Create mesh from NURBS object dialog box, set the way Rhino creates a polygon mesh from the NURBS geometry. Curves do not export.

Save surface trim curves as


When exporting NURBS surfaces, polylines approximate the trimming curves. The geometry does not match the accuracy of exporting trims as curves. This option was originally included for exporting to Alias. Now you should be able to use IGES for exporting to Alias instead.


When exporting NURBS surfaces, the trim curves are NURBS. NURBS trim curves provide more accuracy than exporting trims as polylines.


End-of-line character

Windows (CRLF)

Return + line feed.

Mac OS X, Unix (LF)

Line feed only.

Mac OS 9 (CR)

Return only.

__ Significant digits
Export material definitions

Creates an .mtl file with the same name as the .obj file. The .mtl file contains one material definition per object. There are also references to these materials added to the .obj file.

This option sets OBJ diffuse material to the object's display material if there is no render material assigned.

Use display color for objects with no material set

An object with no material assigned exports with the default material (enabled), otherwise with a material using the object's display color (disabled).

Convert white space in material names to underscores
Map Rhino Z to OBJ Y

Translates the exported model from a z up orientation to a y-up orientation.

Wrap long lines

Checking this option may cause downstream applications fail to read the output file. Uncheck this option if you are not sure whether the target application can handle line wraps.


Export Rhino object names

Exports object names.

Do not export object names
As OBJ groups (Use for export to 3dsMax)
As OBJ objects

Export Rhino layer/group names

These settings make it possible to export data to programs that do not support nested grouping. The OBJ import plug-in for 3ds max is one example. To export to 3ds max, select Do not export layer/group names.

Do not export layer/group names
Layers as OBJ groups
Groups as OBJ groups
Sort by OBJ groups


Export polylines as

Degree 1 bspline
One OBJ line with multiple OBJ vertices
Multiple OBJ lines with 2 OBJ vertices


Vertex welding


Exports a single vertex for any given location (i.e., the topological vertex) but exports all of the normals and texture coordinates associated with the mesh vertex.

Completely unwelded

Unwelds the entire mesh before exporting it

SubD meshing

From SubD surface

Converts SubD surfaces into meshes with the selected meshing density.

Extra coarse
Extra fine
From SubD control net

Extracts SubD control nets as meshes.



Converts NGons into triangle or quad mesh faces.


Keeps NGons, but do not convert any mesh faces into NGons.


Keeps NGons, and converts each planar region (red) into an n-gon. The planar region (blue) with an inner boundary will not be converted.

___Minimum face count

Planar regions with mesh faces less than this number will not be converted into NGons.

Export texture coordinates
Export vertex normals
Export vertex colors

Saves RGB values of vertex colors with the range of 0 to 1.0.


Saves RGB values of vertex colors with the range of 0 to 255.

Export open meshes

Export as triangles

Converts quads to triangles like what the TriangulateMesh command does.

Use render meshes

Enable to export objects with document mesh settings. Polygon mesh export options will not display. Object custom meshes will save to the OBJ file.

Disable to export objects with the polygon mesh export options. Object custom meshes will not save to the OBJ file.

Always use these settings. Do not show this dialog again.

Saves the current settings and turns off the dialog display.

To turn the message back on

See also: ResetMessageBoxes command.

Export notes

See also

Wikipedia: Wavefront OBJ




Rhinoceros 8 © 2010-2024 Robert McNeel & Associates. 16-May-2024