AMF Technical Information
AMF is the ISO/ASTM standard interchange file format for additive manufacturing applications.
AMF is a key component of a standards based, quality "design-to-finished part" process that can automate and integrate key design & quality meta data by embedding it in the AMF file as it moves through the work flow to avoid human error and ensure optimal quality. Using AMF in your AM work flow aids in regulatory quality management compliance and ensures future standards based interoperability. The AMF standard specification is extensible and allows for inclusion of additional metadata in a defined location within the file to meet specific application requirements.
1. Format: AMF files are written in human readable, XML v1.0, UTF-8 or UTF-16.
2. Organization: at root level there are five types of elements allowed: OBJECT, MATERIAL, TEXTURE, CONSTELLATION & METADATA. Only a single OBJECT is required. All other elements are optional.
3. Geometry: the 3D object or objects defined in the file are expressed as closed surface meshes, using lists of vertices and x,y,z coordinates that define each triangle in the mesh. Each object can be defined as a single volume, or consisting of multiple discreet volumes. Every object has a unique ID.
4. Material: the MATERIAL element is used to specify one or more materials, each with its own unique ID, at Volume level, OBJECT level or Root level. MATERIAL elements may contain optional COLOR or COMPOSITE child elements. COMPOSITE elements define composite materials consisting of multiple materials arranged in a homogenous configuration, or in gradations as defined by formula and location within the file.
5. Color: the COLOR element is used to specify color at the object level, volume level, triangle level or vertex level. It can optionally be used to specify color for each specified MATERIAL. Colors and transparency levels are specified using sRGB color model as a default, however other color models may be used as an option. Color gradients may be specified by formula and location within the file.
6. Texture: the TEXTURE element is used to specify 2D and 3D texture data in grayscale. It can be applied to at object, volume, or triangle(facet) level.
7.Constellations: This element is used to define the position and orientation of multiple objects and/or constellations within a single file. This is useful for defining an assembly or a specific build configuration.
8. MetaData: the METADATA element may be used to include additional information about the geometry, materials or objects defined in the file. Examples may include: a name, author, copyright, version number, or instructions. There are over 30 metadata types defined in the specification. Custom meta data types may be added as an option.
9. Compression: an AMF file may be stored in plain text or compressed using the standard ZIP Archive format using the AMF extension. Additional documents may be included in the ZIP file but they will not be parsed when the file is read.
10. Extensibility: the AMF standard specification is defined as extensible. A range of additional functionality is envisioned. The current version 1.2 was published in May 2020. The TC261 committee is active in considering new functionality for a future version 1.3. Examples of some of the new features under consideration for future versions include: tolerances, surface roughness, support structures, functional geometric representations, voxel representations, version history, and additional metadata specifications.
To obtain a copy of the full specification: To view a video demonstrating use of AMF: