AR Glossary

This augmented reality glossary brings together the key AR terms, words, and concepts, explained in plain language for artists, creators, and developers. If you're just starting with WebAR or you already work in spatial computing, you'll find simple definitions for the terminology that shapes augmented reality art.

Search for a concept, follow a guided reading path or browse A–Z. Diagrams and short visual comparisons connect the vocabulary to the objects, surfaces and movement in your artwork.

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7 steps

Place objects

Understand where an object sits, what it rotates around and how the camera changes your view.

Start path

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7 steps

Shape their appearance

Connect shape, surface, light and transparency to the way your artwork looks.

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7 steps

Animate them

Build from a timed change to a moving character, then understand what travels in the export.

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See the difference

Same object, different pivot Perspective vs. orthographic

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Browse A–Z

97 terms

Alternative names are listed under their own letter. Follow “See” to read the full definition.

#

3D animation clip: See Animation Clip
3D audio: See Spatial Audio
3D Gaussian Splatting: See Gaussian Splatting
3D grid: See Reference Grid
3D optimization: See Asset Optimization (3D)
3D picking: See Raycasting
3D point cloud: See Point Cloud
3D replica: See Digital Replica
6D pose: See Pose (AR/XR)

A

Alpha blend: See Alpha Blending
Alpha Blending: Alpha blending combines a surface’s colour with the colour already behind it, using alpha to control their contributions.
Alpha Channel: An alpha channel stores transparency information alongside an image's colour, allowing parts of an image or video to be transparent or partly transparent.
Alpha clipping: See Alpha Masking
Alpha Masking: Alpha masking compares alpha with a threshold, discarding samples below it and keeping those that pass.
Alpha test: See Alpha Masking
Alpha transparency: See Alpha Channel
Angular transform: See Rotation
Animation Clip: An animation clip is a named or grouped sequence of animated property changes that can be played over a defined duration.
Animation key: See Keyframe
Animation sequence: See Animation Clip
AR anchor: See Spatial Anchor
AR drift: See Tracking Drift
AR hit test: See Hit Testing
Armature: See Rigging
Artwork recognition: See Image Recognition
Asset optimisation: See Asset Optimization (3D)
Asset Optimization (3D): 3D asset optimization reduces the cost of loading and displaying an asset while preserving the detail and behaviour its experience needs.
Augmented Reality: Augmented reality, or AR, adds digital content to a view of the physical world, allowing real objects and digital elements to be experienced together.
Augmented Reality Art: See Augmented Reality

B

Backface Culling: Backface culling skips polygons classified as facing away from the camera, rather than drawing both sides.
Basis Universal: Basis Universal is a texture-compression system whose encoded textures can be transcoded into formats supported by different graphics devices.
BasisU: See Basis Universal
Blended transparency: See Alpha Blending
Browser-based AR: See WebAR

C

Cartesian coordinates: See Coordinate System (3D)
Character rig: See Rigging
Child object: See Parenting
Compressed mesh: See Mesh Compression
Coordinate plane: See Reference Plane
Coordinate System (3D): A 3D coordinate system describes positions using an origin and three axes, usually called X, Y and Z.
Coplanar flickering: See Z-Fighting
Cutout rendering: See Alpha Masking

D

Depth API: A depth API gives an application access to information about distances in a scene, which can help it relate digital content to physical surfaces.
Depth Buffer (Z-Buffer): A depth buffer stores depth values for rendered samples so the renderer can compare incoming surfaces with what is already there.
Depth fighting: See Z-Fighting
Depth map: See Depth API
Depth sensing: See Depth API
Digital Replica: A digital replica is a digital representation of a physical object or place, made for a stated purpose such as interpretation, visual exploration, documentation or measurement.
Digital reproduction: See Digital Replica
Distance-based detail: See Level of Detail (LOD)
Draco: See Draco Compression
Draco Compression: Draco is a geometry-compression technology used to reduce the encoded size of 3D meshes and point clouds.
Draw Call: A draw call asks the graphics system to render a batch of geometry using a particular set of rendering state.
Draw order: See Render Order

E

Ease-in: See Easing
Ease-out: See Easing
Easing: Easing shapes how an animated value speeds up or slows down over the course of a transition.
Editor grid: See Reference Grid
Environment lighting: See Image-Based Lighting (IBL)
Environment mapping: See Spatial Mapping
Environment tracking: See World Tracking
Extended Reality: Extended reality, or XR, is an umbrella term for technologies and experiences commonly described as augmented reality, virtual reality and mixed reality.

F

Face culling: See Backface Culling
Face normals: See Surface Normals
Field of View: Field of view, or FOV, is the angular extent of a scene visible through a camera, display or optical system at one time.
Frame Rate (FPS): Frame rate is the number of image frames produced or presented each second, usually expressed as frames per second (FPS). In interactive AR, it helps describe how frequently the visual scene updates.
Framerate: See Frame Rate (FPS)
Frames per second: See Frame Rate (FPS)

G

Gaussian Splatting: Gaussian splatting represents a scene with many overlapping, soft 3D primitives, optimised to reproduce its appearance from different viewpoints.
Geometry compression: See Mesh Compression
GL Transmission Format: See GLB / glTF
GLB / glTF: glTF is a standard for delivering 3D scenes and models. GLB is its binary container, often used to package a model and its associated data into one file.
Global coordinates: See World Coordinates
GPU texture compression: See Texture Compression

H

Hand pose tracking: See Hand Tracking
Hand Tracking: Hand tracking estimates the position and movement of a user's hands, allowing an experience to interpret gestures without relying only on handheld controllers.
Hit Testing: Hit testing checks where a ray or other query intersects a target, often to find a candidate location for AR content.

I

Image Recognition: Image recognition identifies or classifies what appears in an image. In an art experience, it can help match a visitor's photograph to a known artwork.
Image target: See Target Image
Image target tracking: See Image Tracking
Image texture: See Texture
Image Tracking: Image tracking follows the position and orientation of a known image through a camera, keeping digital content aligned with the physical artwork as the viewer moves.
Image-based AR: See Marker-based AR
Image-Based Lighting (IBL): Image-based lighting uses an image of an environment to supply lighting information for rendered surfaces.
In-betweening: See Interpolation
Interactive rendering: See Real-Time Rendering
Interpolation: Interpolation calculates values between known samples, such as the positions or rotations stored in animation keyframes.

J

Jitter (AR Tracking): In AR tracking, jitter is a rapid, unwanted fluctuation in the estimated position or orientation of content, making an overlay appear to tremble against its physical reference.
Joint (3D Animation): A joint is a transform in a digital skeleton that helps define a pose. Moving or rotating joints can carry connected parts and, through skinning, deform a character’s surface.
Joint node: See Joint (3D Animation)

K

Keyframe: A keyframe stores the value of an animated property at a particular time.
Khronos Texture 2: See KTX2
KTX2: KTX2 is a texture container format that stores image data and information needed to deliver textures to graphics applications.

L

Laser scanning: See LiDAR
Latency: Latency is the delay between an action or event and the system's response. In AR, it can affect how quickly the displayed content reacts to movement or input.
Level of Detail (LOD): Level of detail uses different representations of an object to match the amount of detail needed in a particular view.
LiDAR: LiDAR measures distance using laser light. Many distance samples can be combined into a three-dimensional point cloud of an object or environment.
Light Detection and Ranging: See LiDAR
Local Coordinates: Local coordinates describe a position or direction relative to a particular object or parent, rather than the whole scene.
Local space: See Local Coordinates

M

Marker-based AR: Marker-based AR uses a predefined visual reference to detect and position digital content relative to something in the physical world.
Marker-based augmented reality: See Marker-based AR
Markerless AR: Markerless AR places or relates digital content to the environment without requiring a predefined visual marker as its reference.
Markerless augmented reality: See Markerless AR
Material: A material defines how a rendered surface looks and responds to light, using settings and, optionally, textures.
Mesh: A mesh represents a 3D surface using connected vertices, edges and faces. In real-time graphics, those faces are commonly triangles.
Mesh Compression: Mesh compression encodes geometry data more compactly for storage or transmission, with decoding needed before the geometry is used.
Mesh retopology: See Retopology
Meshopt Compression: Meshopt compression encodes 3D buffer data compactly, with a design that supports fast decoding in real-time applications.
Meshoptimizer compression: See Meshopt Compression
Metallic-roughness: See Physically Based Rendering (PBR)
Mixed Reality: Mixed reality describes experiences in which digital content and the physical environment are presented together, often with spatial relationships or interactions between them.
Motion-to-photon latency: See Latency
Move transform: See Translation

N

Neural Radiance Field: A neural radiance field, or NeRF, is a learned representation of a scene that can render new views by predicting colour and density along camera rays.
Node hierarchy: See Scene Graph
Non-uniform scale: See Scale
Normal Map: A normal map stores directions in a texture to change a surface’s lighting detail without changing its geometry.
Normal mapping: See Normal Map

O

Object Origin: An object origin is the zero point of an object’s local coordinate system; it can sit inside, outside or at the edge of its geometry.
Object space: See Local Coordinates
Object zero point: See Object Origin
Occlusion: Occlusion occurs when one object blocks another from view. In AR, it determines whether digital content appears in front of or behind physical objects.
Orientation: See Rotation
Orthographic Projection: Orthographic projection uses parallel viewing rays, so an object’s displayed size does not shrink simply because it is farther from the camera.
Orthographic view: See Orthographic Projection

P

Parallel projection: See Orthographic Projection
Parent-child relationship: See Parenting
Parenting: Parenting makes one object or node a child of another so their transforms can be combined hierarchically.
Passthrough: Video passthrough uses cameras on a headset to show the physical surroundings on its displays, allowing digital content to be combined with that camera view.
Perspective convergence: See Vanishing Point
Perspective Projection: Perspective projection makes objects appear smaller as they move farther from the camera, creating familiar depth cues in a flat image.
Perspective view: See Perspective Projection
Photogrammetry: Photogrammetry uses overlapping photographs to estimate an object's or a scene's three-dimensional structure and, when suitable reference measurements are available, its scale.
Phygital: Phygital describes an experience that connects physical and digital elements so they contribute to the same encounter.
Physical scale: See Real-World Scale
Physical-digital experience: See Phygital
Physically Based Rendering (PBR): Physically based rendering is a family of shading methods that approximate how light interacts with materials using physically motivated rules.
Pivot Point: A pivot point is the reference point around which a rotation or scaling operation takes place.
Planar image tracking: See Image Tracking
Plane Detection: Plane detection estimates flat surfaces in a physical environment, such as a floor, tabletop or wall.
Point Cloud: A point cloud is a set of samples positioned in three-dimensional space. Each point has coordinates and may also store information such as colour or intensity.
Polycount: See Polygon Count
Polygon Count: Polygon count is the number of faces in a mesh; for real-time delivery, the exported triangle count is often the more useful comparison.
Polygon mesh: See Mesh
Pose (AR/XR): In AR and XR, a pose describes where something is and how it is oriented relative to a reference coordinate system at a particular moment.
Pose drift: See Tracking Drift
Pose jitter: See Jitter (AR Tracking)
Position offset: See Translation
Positional audio: See Spatial Audio
Positional tracking: See World Tracking

Q

QR Code: A QR code is a two-dimensional barcode that stores data, commonly a web address. In an AR exhibition, it can give visitors a quick way to open an experience.
Quick Response code: See QR Code

R

Ray cast: See Raycasting
Raycasting: Raycasting sends a mathematical ray from an origin in a direction to find intersections with geometry.
Real-time asset optimization: See Asset Optimization (3D)
Real-Time Rendering: Real-time rendering creates images from a scene quickly enough to respond during an interactive experience, updating the view as the camera, objects or other inputs change.
Real-world occlusion: See Occlusion
Real-World Scale: Real-world scale is the relationship between distances in a digital scene and measured distances in the physical world.
Reference Grid: A reference grid is an editor guide made of regularly spaced lines that helps judge alignment, spacing and scale.
Reference image: See Target Image
Reference Plane: A reference plane is a flat geometric guide used to describe placement, alignment or movement in a 3D scene.
Relocalisation: See Relocalization
Relocalization: Relocalization is the process of finding a device’s pose again within a previously established spatial map or reference.
Render Order: Render order is the sequence in which a renderer submits objects or drawing operations to build an image.
Rendering order: See Render Order
Response delay: See Latency
Retopology: Retopology rebuilds the face layout of a mesh to make its structure more suitable for animation, editing or efficient rendering.
Rigging: Rigging creates the controls and relationships used to pose and animate a 3D object or character.
Rotation: Rotation changes an object’s orientation around an axis and a pivot point.
Rotation centre: See Pivot Point

S

Scale: Scale is a transform that multiplies an object’s size along one or more axes.
Scene Graph: A scene graph organises scene elements and their relationships, often as a hierarchy of parent and child nodes.
Scene hierarchy: See Scene Graph
Scene reconstruction: See Spatial Mapping
Scene units: See Real-World Scale
Simultaneous Localization and Mapping: Simultaneous localization and mapping, or SLAM, estimates a device's position while building or updating a map of its surroundings.
Six Degrees of Freedom: Six degrees of freedom, or 6DoF, describe three directions of positional movement and three directions of rotation in three-dimensional space.
Skeleton joint: See Joint (3D Animation)
Skin weights: See Skinning
Skinning: Skinning binds a mesh to a set of joints so that moving the joints deforms the surface.
Spatial Anchor: A spatial anchor is a reference pose used by an AR system to keep digital content associated with a location and orientation in its understanding of the environment.
Spatial Audio: Spatial audio uses information about sound sources and a listener to create the impression that sound comes from positions or directions in space.
Spatial Computing: Spatial computing describes computing that uses position, movement and relationships in three-dimensional space as part of how people interact with digital content.
Spatial interaction: See Spatial Computing
Spatial Mapping: Spatial mapping builds a digital representation of the surrounding physical environment for use by a spatial application.
Spatial pose: See Pose (AR/XR)
Surface detection: See Plane Detection
Surface material: See Material
Surface Normals: Surface normals are directions associated with a surface that help the renderer determine how it should be shaded.

T

Tangent-space normal map: See Normal Map
Target Image: A target image is a prepared visual reference that an AR system uses to recognise a physical image and, when supported, estimate its position and orientation.
Texture: A texture is image or sampled data used by a material to vary a surface property across an object.
Texture Compression: Texture compression reduces the storage or graphics-memory cost of texture data, with trade-offs in quality and compatibility.
Texture map: See Texture
Three.js: Three.js is an open-source JavaScript library for creating and displaying 3D graphics on the web. It provides tools for scenes, cameras, geometry, materials, lighting and animation.
Timing curve: See Easing
Tracking Drift: Tracking drift is a growing error in an estimated position or orientation that makes virtual content gradually lose alignment with its intended physical location.
Tracking jitter: See Jitter (AR Tracking)
Tracking recovery: See Relocalization
Transform (3D): A 3D transform describes how an object is positioned, oriented and scaled relative to a reference frame.
Transform pivot: See Pivot Point
Transformation: See Transform (3D)
Translation: Translation moves an object by an offset without, by itself, changing its orientation or shape.
Transparency channel: See Alpha Channel
Triangle count: See Polygon Count
Triangle mesh: See Mesh
Tweening: See Interpolation

U

Uniform scale: See Scale
Units and dimensions: See Real-World Scale
Universal texture compression: See Basis Universal
Unlit Material: An unlit material displays its base colour without calculating a response to scene lighting.
Unlit shader: See Unlit Material
Unshaded material: See Unlit Material
UV coordinates: See UV Mapping
UV Mapping: UV mapping assigns 2D texture coordinates to a 3D surface so the renderer knows which part of a texture belongs at each point.
UV unwrap: See UV Mapping

V

Vanishing Point: A vanishing point is the location in a perspective image toward which the projections of a set of parallel lines appear to converge.
Vertex normals: See Surface Normals
Vertex skinning: See Skinning
Video passthrough: See Passthrough
Video see-through: See Passthrough
Virtual Reality: Virtual reality, or VR, presents a computer-generated environment that replaces the user's main view of the physical surroundings, typically through a headset.
Visual recognition: See Image Recognition
Visual SLAM: See Simultaneous Localization and Mapping
Visual-inertial SLAM: See Simultaneous Localization and Mapping

W

Web Graphics Library: See WebGL
Web-based augmented reality: See WebAR
WebAR: WebAR is augmented reality delivered through a web browser, so visitors can open an experience from a link without installing a dedicated application.
WebGL: WebGL is a browser graphics API that lets web applications draw hardware-accelerated 2D and 3D graphics in a canvas without installing a browser plugin.
WebGPU: WebGPU is a web API for graphics rendering and general-purpose computation on supported GPUs, giving applications explicit tools for organising GPU resources and work.
WebGPU API: See WebGPU
WebXR: WebXR is a browser API that gives web applications access to supported immersive AR and VR capabilities, including views and device poses.
WebXR Device API: See WebXR
Weight painting: See Skinning
Work plane: See Reference Plane
World Coordinates: World coordinates describe positions and directions in the shared reference frame of a scene.
World space: See World Coordinates
World Tracking: World tracking estimates a device's position and orientation relative to its surroundings, allowing digital content to remain associated with a location in the environment.

X

XYZ: See Coordinate System (3D)

Y

Yaw: Yaw is a change in heading: a left-or-right turn around the up axis of a chosen reference frame. Which coordinate axis represents that turn depends on the convention being used.
Yaw rotation: See Yaw

Z

Z-buffer: See Depth Buffer (Z-Buffer)
Z-Fighting: Z-fighting is a rendering artefact in which overlapping surfaces have depth values too similar to be resolved consistently.

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