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

  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

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

See also: ResetMessageBoxes command.

Export

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.
  6. If the export can be configured, click the Options button to specify export settings.
  7. If the file type creates only mesh objects, in the Polygon Mesh Objects dialog box, specify the mesh settings.

OBJ Export Options

Geometry

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

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.

Formatting

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.

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.

Naming

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

 

OBJ is an ASCII format and does not support multi-byte character sets, such as Chinese, Japanese and Korean. Multi-byte character names will not remain in OBJ export.

Mesh

Vertex welding

Unmodified
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.

Completely unwelded

Unwelds the entire mesh before exporting it

NGons

Create NGons
___Minimum face count
Export texture coordinates
Export vertex normals
Export vertex colors
Export open meshes
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 6 © 2010-2020 Robert McNeel & Associates. 11-Nov-2020