Usage:

  java ObjLoad [-s] [-n] [-t] [-c degrees] <.obj file>
    -s Spin (no user interaction)
    -n No triangulation
    -t No stripification
    -c Set crease angle for normal generation (default is 60 without
       smoothing group info, otherwise 180 within smoothing groups)
  

The ObjectFile class implements the Loader interface for the Wavefront ..obj file format, a standard 3D object file format created for use with Wavefront's Advanced Visualizer (tm) and available for purchase from Viewpoint DataLabs, as well as other 3D model companies. Object Files are text based files supporting both polygonal and free-form geometry (curves and surfaces). The Java 3D .obj file loader supports a subset of the file format, but it is enough to load almost all commonly available Object Files. Free-form geometry is not supported.

The Object File tokens currently supported by this loader are:

v, vn, vt

f (int, int/int, int/int/int)

A polygonal face. The numbers are indexes into the arrays of vertex positions, texture coordinates, and normals respectively. There is no maximum number of vertices that a single polygon may contain. The .obj file specification says that each face must be flat and convex, but if the trIANGULATE flag is sent to the ObjectFile constructor, each face will be triangulated by the Java 3D Triangulator, and therefore may be concave. A number may be omitted if, for example, texture coordinates are not being defined in the model. Numbers are normally positive indexes, but may also be negative. An index of -1 means the last member added to the respective array, -2 is the one before that, and so on.

Faces defined after this token will be added to the named group. These geometry groups are returned as separated Shape3D objects attached to the parent SceneGroup. Each named Shape3D will also be in the Hashtable returned by Scene.getNamedObjects(). It is legal to add faces to a group, switch to another group, and then add more faces to the original group by reissuing the same name with the g token. If faces are added to the model before the g token is seen, the faces are put into the default group called "default."

If the vn token is not used in the file to specify vertex normals for the model, this token may be used to put faces into groups for normal calculation ("smoothing groups") in the same manner as the 'g' token is used to group faces geometrically. Faces in the same smoothing group will have their normals calculated as if they are part of the same smooth surface. To do this, we use the Java 3D NormalGenerator utility with the creaseAngle parameter set to PI (180 degrees - smooth shading, no creases) or to whatever the user has set the creaseAngle. Faces in group 0 or 'off' use a creaseAngle of zero, meaning there is no smoothing (the normal of the face is used at all vertices giving the surface a faceted look; there will be a crease, or "Hard Edge," between each face in group zero). There is also an implied hard edge between each smoothing group, where they meet each other.

If neither the vn nor the s token is used in the file, then normals are calculated using the creaseAngle set in the contructor. Normals are calculated on each geometry group separately, meaning there will be a hard edge between each geometry group.

The current (and subsequent) geometry groups (specified with the 'g' token) have applied to them the named material property. The following set of material properties are available by default:

amber	amber_trans	aqua	aqua_filter
archwhite	archwhite2	bflesh	black
blondhair	blue_pure	bluegrey	bluetint
blugrn	blutan	bluteal	bone
bone1	bone2	brass	brnhair
bronze	brown	brownlips	brownskn
brzskin	chappie	charcoal	deepgreen
default	dkblue	dkblue_pure	dkbrown
dkdkgrey	dkgreen	dkgrey	dkorange
dkpurple	dkred	dkteal	emerald
fgreen	flaqua	flblack	flblonde
flblue_pure	flbrown	fldkblue_pure	fldkdkgrey
fldkgreen	fldkgreen2	fldkgrey	fldkolivegreen
fldkpurple	fldkred	flesh	fleshtransparent
flgrey	fllime	flltbrown	flltgrey
flltolivegreen	flmintgreen	flmustard	florange
flpinegreen	flpurple	flred	fltan
flwhite	flwhite1	flyellow	glass
glassblutint	glasstransparent	gold	green
greenskn	grey	hair	iris
jetflame	lavendar	lcdgreen	lighttan
lighttan2	lighttan3	lighttannew	lightyellow
lime	lips	ltbrown	ltgrey
meh	metal	mintgrn	muscle
navy_blue	offwhite.cool	offwhite.warm	olivegreen
orange	pale_green	pale_pink	pale_yellow
peach	periwinkle	pink	pinktan
plasma	purple	red	redbrick
redbrown	redorange	redwood	rubber
ruby	sand_stone	sapphire	shadow
ship2	silver	skin	sky_blue
smoked_glass	tan	taupe	teeth
violet	white	yellow	yellow_green
yellowbrt	yelloworng

mtllib filename

Load material properties from the named file. Materials with the same name as the predefined materials above will override the default value. Any directory path information in (filename) is ignored. The .mtl files are assumed to be in the same directory as the .obj file. If they are in a different directory, use Loader.setBasePath() (or Loader.setBaseUrl() ). The format of the material properties files are as follows:

newmtl name

Start the definition of a new named material property.

Ka Ambient color.

Kd Diffuse color.

Ks Specular color.

illum (0, 1, or 2)

0 to disable lighting, 1 for ambient & diffuse only (specular color set to black), 2 for full lighting.

Ns Shininess (clamped to 1.0 - 128.0).

map_Kd filename

Texture map. Supported file types are .gif, .jpg, .xbm, .rgb, .rgba, .int, .inta, .sgi, and .bw.