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.

Import

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

From the File menu, click Open or Import.

In the Open dialog box, select the supported file type.

If the import can be configured, click Options to specify import settings.

Click Open, or press Enter.

Note: When Rhino opens a non-3dm model, the title bar reflects the name of the model that was opened. When the model is saved for the first time, this model name is entered as the file name.

OBJ Import Options

Import OBJ groups as

Nothing

Groups

Layers

Object names

Import OBJ objects

Import as morph target only

Reverse group order

Ignore textures

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

Click Options in the appropriate Save, Export, Open, Import, or Insert dialog box.

Export

To save as or export a Rhino model

From the File menu, click Export Selected or Save As.

In the dialog box, the Files of type list displays the currently supported file types for export.

In the Files of type box, select the supported file type.

In the File name box, select or type a file name.

Specify what is to be saved.

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.

If the export can be configured, click Options to specify export settings.

If the file type creates only mesh objects, in the Polygon Mesh Objects dialog box, specify the mesh settings.

OBJ Export Options

Save objects as

NURBS

Rhino curves and surfaces export as NURBS curves and surfaces.

Polygon mesh

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

Polylines

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.

Curves

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.

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

Exports layer 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

Vertex welding

Unmodified

Completely unwelded

Unwelds the entire mesh before exporting it

Welded

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.

__ Significant digits

Export mesh texture coordinates

Export mesh vertex normals

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.

Map Rhino Z to OBJ Y

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

Wrap long lines

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

Click Options in the appropriate Save, Export, Open, Import, or Insert dialog box.

Export notes

●

Attempting to export invalid objects will cause the export to fail. Use the SelBadObjects command to find invalid objects before exporting.

●

Assign a material name to an object in Material Properties. This material name is exported for use by the renderer.

●

Layer names and object names export into the OBJ file as OBJ group names. Spaces in the layer or object names are converted into underbar (_) characters.