NGenesis/bom-obj2bom

Converts OBJ and associated MTL files to BOM (Binary Object/Material) file format.

obj2bom

A command line tool to convert OBJ and associated MTL files to BOM (Binary Object/Material) file format.

Command Line Usage

obj2bom <output.bom> <input1.obj> [input2.obj] [...inputN.obj]

Features

• Convert OBJ/MTL files in to a compact binary representation for efficient storage, transport and parsing.
• Combine multi-part models consisting of many OBJ/MTL files into a single BOM file.
• Automatic conversion of quad face geometry into triangulated face geometry.
• Automatic indexing of geometry buffers.
• Supports two UV channels and lightmap channel.
• Comment Annotation Syntax for OBJ and MTL provides support for embedding BOM properties into OBJ/MTL files without breaking existing parsers.

Known Limitations

• N-gon face geometry is not supported.
• Point/Line/Curve/Surface geometry is not supported.
• 3D texture coordinates are not supported.

Comment Annotation Syntax (CAS)

Comment Annotation Syntax provides support for embedding non-standard BOM geometry and material properties into OBJ and MTL files using comment lines without breaking compliance with existing OBJ/MTL file specifications and parsers.

Note that the characters <>[]| in the provided documentation are not considered literal syntax.

• <property> denotes a required property.
• [property] denotes an optional property.
• <property1|property2|property3> or [property1|property2|property3] denotes a required or optional property which can be one of several available properties.
• No indication denotes a required literal property.

Syntax

# :<vendor>: <property> [[-flag1] [value1] [value2] [...valueN]] [[-flag2] [value1] [value2] [...valueN]] [[...-flagN] [value1] [value2] [...valueN]]

BOM Material Properties (MTL-compatible)

Face Culling (cull_face)

Syntax:

# :BOM: cull_face <none|front|back|all>

Available options:

• none: Disables culling of faces, used to display double sided materials.
• front: Culls only front faces.
• back: Culls only back faces.
• all: Culls both front and back faces.

Light Map (lightmap)

Syntax:

# :BOM: lightmap [-o <offset_u> <offset_v>] [-s <scale_u> <scale_v>] [-intensity <intensity_modifier>] <path>

Available options:

• -o <offset_u> <offset_v>: Specifies UV offset of the light map texture.
• -s <scale_u> <scale_v>: Specifies UV scaling of the light map texture.
• -intensity <intensity_modifier>: Intensity modifier to be applied to the light map, where a larger modifier produces a greater intensity. Defaults to 1.
• path: File path of the light map texture file.

BOM Geometry Properties (OBJ-compatible)

UV Channel 2 (vt2)

Syntax:

# :BOM: vt2 <u> <v> [w]

Available options:

• u: U component of a 2D texture coordinate.
• v: V component of a 2D texture coordinate.
• w: W component of a 3D texture coordinate. Reserved for future use and is currently skipped by the parser.

See also

bom-three.js - A javascript library to import BOM (Binary Object/Material) files into three.js.