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, Insert, Import, or Worksession > Attach.
- In the dialog box, select a supported file type.
- Click 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
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.
Export
To save as or export a Rhino model
- On 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.
- If the export can be configured, click the button to specify export settings.
- If the file type creates only mesh objects, in the Polygon Mesh Objects dialog box, specify the mesh settings.
| 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. |
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.
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.
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
SubD meshing
From SubD surface
Converts SubD surfaces into meshes with the selected meshing density.
Extra coarse
Coarse
Medium
Fine
Extra fine
From SubD control net
Extracts SubD control nets as meshes.
NGons
None
Converts NGons into triangle or quad mesh faces.
Preserve
Keeps NGons, but do not convert any mesh faces into NGons.
Create
Keeps NGons, and converts each planar region (red) into an NGon. 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
Export open meshes
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
- 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
- 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.