Glossary

Term	Also Known As	Definition
3D creator		Someone who is creating 3D model(s) of real world or imaginary objects, visualizations, environments or theoretical arguments.
Access		The ability and/or permission to discover, examine, retrieve, and/or reuse information (e.g., 3D data) through the use of search engines, catalogs, indexes, finding aids, documentation, or other tools.
Accuracy		The proximity of a measured value to a standard or known value. High accuracy, similar to high precision, implies that the difference between the values is small. This term is commonly misused.
Administrative metadata		Administrative Metadata is used in managing and administering collections and information resources, and can comprise both technical and preservation metadata. It is  generally used for internal management of digital resources. It can include acquisition information, rights and reproduction tracking, documentation of legal access requirements, location information, selection criteria for digitization, and use analytics https://ndsa.org/glossary/Gilliland, Anne J. “Setting the Stage.” In Introduction to Metadata, edited by Murtha Baca. 3rd ed. Los Angeles: Getty Publications, 2016. http://www.getty.edu/publications/intrometadata/setting-the-stage/
Aggregator		An entity that is gathering assets from other institutions and making them available (i.e., sharing/disseminating assets).
Archival information package (AIP)		As defined by the OAIS, an AIP is the set of content and metadata managed by a preservation repository, and organized in a way that allows the repository to perform preservation services. https://www2.archivists.org/groups/standards-committee/open-archival-information-system-oais
Archive		An entity that looks to preserve assets for future use.
Avatar		An icon or figure representing an actor in a digital setting.
Bitstream preservation	preservation	Technical measures such as checksums and redundancy that aim to ensure the bits comprising a file remain unchanged over time and after changes in technology. It is a basic prerequisite for digital long-term preservation.
Born digital		We do not recommend using this term in a context as diverse as CS3DP, as its application with respect to 3D data is complicated and may be misleading.
Checksum		A checksum on a file is a ‘digital fingerprint’ whereby even the smallest change to the file will cause the checksum to change completely. Checksums are typically created using cryptographic techniques and can be generated using a range of readily available and open source tools. It is important to note that whilst checksums can be used to detect if the contents of a file have changed, they do not tell you where in the file that the change has occurred. https://www.dpconline.org/handbook/technical-solutions-and-tools/fixity-and-checksums
CIDOC CRM – Conceptual Reference Model		An ISO standard semantic ontology created by the International Council of Museums (ICOM) and recently adopted by the International Federation of Libraries. The CIDOC Conceptual Reference Model (CRM) provides definitions and a formal structure for describing the implicit and explicit concepts and relationships used in cultural heritage documentation. (see http://www.cidoc-crm.org)
Computer Aided Design (CAD)		Computer system to develop or optimize a design. It is often used in fields, such as architecture, to create 3D representations. Common output is a NURBS model.
Content standards		Guidelines or rules for how elements are selected, formatted, & recorded. e.g. Anglo-American Cataloging Rules, 2nd edition (AACR2), Resource Description and Access (RDA), Cataloging Cultural Objects (CCO), Describing Archives: A Content Standard (DACS)
Controlled vocabulary		Domain-specific lists of allowable values for certain metadata elements. Classification schemes are often connected to a chosen vocabulary.  e.g. Library of Congress Subject Headings (LCSH), Library of Congress Names Authority File (LCNAF), (Virtual International Authority File (VIAF), Medline Subject Headings (MeSH), Art and Architecture Thesaurus (AAT), Thesaurus of Geographic Names (TGN), Union List of Artist Names (ULAN)…
Data curator		A person who reviews and modifies (or suggests modification) for datasets and their documentation to ensure they are preserved for long-term access and reusability.
Data model		A data model (or data model) is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. https://en.wikipedia.org/wiki/Data_model
Descriptive metadata		Metadata that describes a digital entity for purposes such as discovery and identification, (e.g., title, creator, summary, tags, etc.) https://ndsa.org/glossary/
Digital asset lifecycle	digital curation lifecycle	A conceptual model used to identify the stages required for successful curation and preservation of data from initial conceptualisation through the iterative curation cycle. This model can be used to plan activities within a specific research project, organisation, or consortium to ensure all necessary stages are undertaken.
Digital curation		the active and ongoing management of data through its lifecycle of interest and usefulness to scholarship, science, and education. Data curation enables data discovery and retrieval, maintains data quality, adds value, and provides for re-use over time through activities including authentication, archiving, management, preservation, and representation.(http://www.lis.illinois.edu/academics/ programs/specializations/data_curation)
Digital preservation		Refers to the series of managed activities necessary to ensure continued access to digital materials for as long as necessary. (https://dpconline.org/handbook/glossary) Digital preservation seeks to prevent loss of digital information from medium failures and hardware/software obsolescence.
Digital repository		System in which digital assets are deposited, stored, managed, and sometimes archived.
Discovery		Identifying potentially relevant materials through the process of searching. The application of metadata and persistent identifiers are methods by which data can become discoverable.
Dissemination Information Package (DIP)		As defined by the OAIS, a DIP is distributed to a consumer by the repository in response to a request, and may contain content spanning multiple AIPs. https://www2.archivists.org/groups/standards-committee/open-archival-information-system-oais
Emulation	preservation	A means of overcoming technical obsolescence of hardware and software using tools and techniques for imitating obsolete systems.
Fixity		The state of being unchanged, usually used in reference to a digital file or object. Fixity is usually checked by calculating, storing, and comparing a checksum value for the file or object.
Good/Better/Best		A continuum of practices ranging from the minimum, which includes required practices that can be accomplished with limited resources, to the maximum, which assumes greater resource availability and can ensure robust support of a digital asset through its lifecycle.
Image resolution		Number of pixels per fixed space in raster data.
Laser scan		Laser scanning is the process of recording precise three dimensional information of a real world object or environment. This can include handheld laser line probes, ground based terrestrial lidar, and aerial based LiDAR that can be used to scan at a range of scales from very small objects to very large monuments or entire sites. Laser scanners rapidly sample or scan an object’s surface recording shape and often visual properties (intensity and/or RGB information). The information is often returned to the unit as a dense collection of precisely measured XYZ points referred to as a point cloud. http://guides.archaeologydataservice.ac.uk/g2gp/LaserScan_1-2
Manifold mesh	watertight model	A hole-free mesh with no open edges. All edges have exactly two incident triangles. All vertices have exactly one cycle of incident triangles. All triangles in the mesh are consistently oriented. https://www.blender.org/forum/viewtopic.php?t=1012
Mesh	3D model, polygonal model	A collection of vertices (points), edges (straight line segment connecting 2 vertices), and faces that describe the shape of a 3D object.
Metadata		See technical metadata, administrative metadata, descriptive metadata, or preservation metadata
Mode	3D modes	In this text, mode is referred to as methods of 3D generation (e.g. photogrammetry) or output. It may also refer to methods of interaction (e.g. virtual world)
Multi-modal model	Hybrid model, 3D model	A 3D model resulting from a combination of methods (modes), including reality-based capture (multi-sensor) and/or any other creation method.
NURBS model	3D model	Non-uniform rational B-spline – Wikipedia. a mathematical model commonly used in computer graphics for generating and representing curves and surfaces.
Paradata	documentation; codebook; process data; methods documentation	Data regarding hypothesis, concept, or intent behind a model; the human intent; process behind creating the model. This may include methods used or variables. A recipe to recreate a 3D model.
Persistent identifier		A long lasting reference to a digital resource such as a digital object identifier (DOI) or ARK (archival reference key).https://support.orcid.org/hc/en-us/articles/360006971013-What-are-persistent-identifiers-PIDs-
Photogrammetry		Digital photogrammetry falls under the broader category of Geomatics, and, according to the American Society for Photogrammetry and Remote Sensing, is defined as, “the art, science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images…” (Salma, 1980). A simplified definition could be the extraction of three-dimensional measurements from two-dimensional data (i.e. images). Close-range (terrestrial) photogrammetry refers to the acquisition of photographs from a lesser distance than traditional aerial (or orbital) photogrammetry.  https://guides.archaeologydataservice.ac.uk/g2gp/Photogram_1-1
Platform migration	preservation	A means of overcoming technical obsolescence by transferring digital resources from one hardware/software generation to the next.
Point cloud		A set of 3D data points usually resulting from surface capture methods. Point clouds differ from a mesh in that points are not connected by edges or faces.  May include additional information such as point color.
Precision		The proximity of two or more repeated measurements to each other. Precision is achievable without accuracy. High precision, similar to high accuracy, implies that the difference between the values is small. This term is commonly misused.
Preservation		See Digital Preservation.
Preservation Intervention Point	PIP	Points in the progression of the digital asset lifecycle at which it might be advisable to stop and document, save versions of files for preservation, or take other preservation actions.
Preservation  metadata		The information necessary support the long-term retention and accessibility of digital content. Preservation metadata also establishes the authenticity of digital content, and records the chain of custody and provenance for a digital object. https://ndsa.org/glossary/
Provenance		Provenance is information about entities, activities, and people involved in producing a piece of data or thing, which can be used to form assessments about its quality, reliability or trustworthiness.It allows to establishes the chain-of-custody information needed for users to make trust decisions about digital data.
README file		A README file contains information about other files in a directory or archive of computer software. A form of documentation, it is usually a simple plain text file with the text README in the file name. https://en.wikipedia.org/wiki/README
Realia		A library science term for physical three-dimensional objects that do not fit easily in the categories for printed material.
Registration	processing step	Transforming multiple sets of 3D data to one coordinate system so they are in meaningful positions relative to each other. A manual or automated process which aligns two or more data sets (e.g., surfaces or volumes) to each other.
Render	processing-step/output	Rendering is the process of generating a 2D image from a 3D model/scene by means of computer programs. Also, the image which results from rendering can be called a render. -modified from wikipedia
Repository manager		A person who oversees infrastructure and handles ingestion, management, and discoverability of data in a data repository.
Reprojection error		Reprojection error is a geometric error corresponding to the image distance between a projected point and a measured point. It is used to quantify how closely an estimate of a 3D point recreates the point’s true projection.
Resolution		Resolution usually refers to the level of detail in a 2D raster image or 3D voxel based model. For a 3D mesh, resolution is not an appropriate term, instead consider using point count or face count. See also image resolution.
RTI – Reflectance Transformation Imaging		A technique for creating detailed surface information from a single camera point of view.  The resulting data can be interactively relit, and mathematically enhanced.  Used in art conservation, rock art, deciphering inscriptions, and other uses where very fine surface details are needed.  The format is pixel based (i.e. 2D) but includes 3D information along with color and reflectance data – this is sometimes referred to as 2 1/2 D. Also referred to as PTM (Polynomial Texture Mapping)
Sidecar		Sidecar files, also known as buddy files or connected files, are computer files that store data (often metadata) which is not supported by the format of a source file. https://en.wikipedia.org/wiki/Sidecar_file
Software emulation		The process of recreating, on current hardware, the technical environment required to view and use digital objects from earlier times. Holdsworth, D., Wheatley, P.R.: Emulation, preservation and abstraction. In: RLG Diginews, vol. 5, no. 4 (2001).
Source material		The data and references material used to create a manually built 3D model (e.g.drawings, notes, measurements)
Structured light		A method of scanning real objects or environments that relies on the distortion of projected light to calculate surface form. A known pattern (often a grid or horizontal lines) of light projected onto a surface appears distorted from perspectives other than that of the projector, and this can be used for geometric reconstruction of the surface shape.
Submission Information Package (SIP)		As defined by the OAIS, a SIP is the content and metadata received from an information producer by a preservation repository. https://www2.archivists.org/groups/standards-committee/open-archival-information-system-oais
Technical metadata		Metadata that describes the technical state of and process used to create a file. Often closely related either to its file format or the original software used to create the file, e.g. scanning equipment and settings used to create or modify a digital object. https://ndsa.org/glossary/
Texture map	3D model, UV Map	An image file which is applied to the surface of a 3D model (often in UV space) to provide color, specularity, or other surface properties. Examples of named texture maps would include, but are not limited to: normal maps, diffuse maps, ambient occlusion maps, displacement maps, and bump maps.
Transformation	Format migration	To transform a file from an obsolete, unsupported, or closed format into a newer, open, or supported format .
Usability		The extent to which a product can be used to achieve articulated goals with effectiveness, efficiency and satisfaction for a specific context of use. Modified from the official ISO 9241-11 definition of usability. (Interaction Design Foundation: https://www.interaction-design.org/literature/topics/usability)
UV space	3D model	The coordinates which map one or more 2D texture maps to the 3D geometry.
Volumetric capture data		3D raster data usually represented by a DICOM or image stack, or binary file, which represents data on a regularly spaced (usually), three-dimensional grid. Each unit, voxel, can contain extra information such as opacity, density, color. Volumetric data can be captured by various technologies such as magnetic resonance imaging (MRI) and X-ray computed tomography (CT).
Voxel		A voxel is the basic volume element (often cubic) in a 3 dimensional array, as a pixel is the basic area element (often square) in a 2 dimensional array.
Watertight mesh	3D model, Manifold	A mesh that has no holes, is completely enclosed. If you filled it with water, it would not leak. A mesh must be watertight for it to be 3D printed.
Workflow		The sequence of events and processes that comprise the life cycle  of a 3D work from initiation to curation.
X-ray Computed Tomography (CT)	CAT scan	A CT scan, also known as computed tomography scan, and formerly known as a computerized axial tomography scan or CAT scan,makes use of computer-processed combinations of many X-ray measurements taken from different angles to produce cross-sectional (tomographic) images (virtual “slices”) of specific areas of a scanned object, allowing the user to see inside the object without cutting. wikipedia