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	Glossary	Glossary
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	.. For writing style guide, see: :doc:`/about/contribute/style_guides/writing_guide`	These following pages lists terms and defintions that are used in this manual
	If you add new entries, keep the alphabetical sorting!	as well as terms that are important to a 3D artist.

	This page lists definitions for terms used in Blender and this manual.	.. toctree::
		:maxdepth: 2

	.. glossary::	blender_terms.rst
		computer_graphics.rst
	Active	math.rst
	One of the three :doc:`selection states </editors/3dview/object/selecting>`.	color_theory.rst
	Only one object or item can be active at any given time.

	Action Safe
	Area of the screen visible on most devices. Place content inside it to ensure it does not get cut off.

	Actuator
	A :term:`logic brick` that acts like a muscle of a lifeform. It can move the object, or make a sound.

	Aliasing
	Rendering artifacts in the form of jagged lines.

	Alpha Channel
	Additional channel in an image for transparency.

	Straight Alpha
	Method where RGBA channels are stored as (R, G, B, A)
	channels, with the RGB channels unaffected by the alpha channel.
	This is the alpha type used by paint programs such as Photoshop or Gimp,
	and used in common file formats like PNG, BMP or Targa.
	So, image textures or output for the web are usually straight alpha.

	Premultiplied Alpha
	Method where RGBA channels are stored as (R ├ù A, G ├ù A, B ├ù A, A),
	with the alpha multiplied into the RGB channel.

	This is the natural output of render engines,
	with the RGB channels representing the amount of light that comes toward the viewer,
	and alpha representing how much of the light from the background is blocked.
	The OpenEXR file format uses this alpha type.
	So, intermediate files for rendering and compositing are often stored as premultiplied alpha.


	Conversion (Straight/Premultiplied) Alpha
	Conversion between the two alpha types is not a simple operation and can involve data loss,
	as both alpha types can represent data that the other cannot though it is often subtle.

	Straight alpha can be considered to be an RGB color image with a separate alpha mask.
	In areas where this mask is fully transparent, there can still be colors in the RGB channels.
	On conversion to premultiplied alpha this mask is applied'
	and the colors in such areas become black and are lost.

	Premultiplied alpha, on the other hand, can represent renders
	that are both emitting light and letting through light from the background.
	For example, a transparent fire render might be emitting light,
	but also letting through all light from objects behind it.
	On converting to straight alpha, this effect is lost.

	Ambient Light
	The light that comes from the surrounding environment as a whole.

	Ambient Occlusion
	A ratio of how much :term:`ambient light` a surface point would be likely to receive.
	If a surface point is under a foot or table,
	it will end up much darker than the top of someone's head or the tabletop.

	Animation
	Simulation of motion.

	Anti-aliasing
	See :term:`oversampling`.

	Armature
	An :term:`Object` consisting of :term:`bones <bone>`. Used to :term:`rig` characters, props, etc.

	Axis
	A reference line which defines coordinates along one cardinal direction in n-D space.

	Axis Angle
	Rotation method where X, Y, and Z correspond to the axis definition,
	while W corresponds to the angle around that axis, in radians.

	Baking
	The process of computing and storing the result of a potentially time-consuming calculation
	so as to avoid needing to calculate it again.

	Bevel
	The operation to chamfer or bevel edges of an object.

	BU
	Blender Units
	Internal units used by Blender, equivalent to meters. Often abbreviated to "BU".

	Bone
	The building block of an :term:`Armature`. Made up of a :term:`Head`, :term:`Tail`
	and :term:`Roll Angle` which define a set of local axes and a point of rotation at the :term:`Head`.

	Boolean
	A type of logic dealing with binary true/false states.

	See also :doc:`Boolean Modifier </modeling/modifiers/generate/booleans>`.

	Bounce
	Refers to the reflection or transmission of a light ray upon interaction with a material.
	See also :doc:`Light Paths </render/cycles/settings/light_paths>`.

	Bounding Box
	The box that encloses the shape of an object. The box is aligned with the local space of the object.

	Bump Mapping
	Technique for simulating slight variations in surface height using a grayscale "height-map" texture.

	B├⌐zier
	A computer graphics technique for generating and representing curves.

	BVH
	Bounding Volume Hierarchy
	A hierarchical structure of geometric objects.

	See also `Bounding Volume Hierarchy <https://en.wikipedia.org/wiki/Bounding_volume_hierarchy>`__ on Wikipedia.

	Caustics
	Bright concentrations of light focused by specularly reflecting or refracting objects.

	Child
	An :term:`Object` that is affected by its :term:`Parent`.

	Chroma
	Chrominance
	In general, a resulting image color decomposition, where its (L or Y) luminance channel is separated.
	There are two different contexts whereas this term is used:

	Video systems
	Refers to the general color decomposition resulting in Y (Luminance) and C (Chrominance) channels,
	whereas the chrominance is represented by: U = ( Blue minus Luminance ) and V = ( Red minus Luminance ).
	Matte compositing
	Refers to a point in the color gamut surrounded by a mixture
	of a determined spectrum of its RGB neighboring colors.
	This point is called Chroma key and this key
	(a chosen color) is used to create an Alpha Mask.
	The total amount of gamut space for this chrominance point is defined
	by users in a circular or square shaped format.

	Clamp
	Clamping
	Limits a variable to a range. The values over or under the range are set
	to the constant values of the ranges minimum or maximum.

	Blend Modes
	Color Blend Modes
	Methods for blending two colors together.

	See also `Blend Modes <https://docs.gimp.org/en/gimp-concepts-layer-modes.html>`__ on GIMP docs.

	Color Space
	A coordinate system in which a vector represent a color value.

	RGB
	Red-Green-Blue traditional primary colors also broadcast directly to most computer monitors.
	HSV
	Three values, often considered as more intuitive (human perception) than the RGB system.

	Hue
	The Hue of the color.
	Saturation
	The quantity of hue in the color (from desaturated -- a shade of gray -- to saturated -- brighter colors).
	Value
	The brightness of the color (dark to light).
	HSL
	Hue, Saturation
	See HSV.
	Luminance
	TODO.
	YUV
	Luminance-Chrominance standard used in broadcasting analog PAL (European) video.
	YCbCr
	Luminance-ChannelBlue-ChannelRed Component video for digital broadcast use,
	whose standards have been updated for HDTV and commonly referred to as the HDMI format for component video.
	\+A
	The color space holds an additional :term:`Alpha Channel`.

	Concave face
	Face in which one vertex is inside a triangle formed by other vertices of the face.

	Constraint
	A way of controlling one :term:`object` with data from another.

	Controller
	A :term:`logic brick` that acts like the brain of a lifeform.
	It makes decisions to activate muscles (:term:`actuators <actuator>`),
	using either simple logic or complex Python scripts.

	Convex face
	Face where, if lines were drawn from each vertex to every other vertex, all lines would remain in the face.
	Opposite of a :term:`concave face`.

	Coplanar
	Refers to any set of elements that are all aligned to the same 2D plane in 3D space.

	Crease
	Property of an :term:`edge`. Used to define the sharpness of edges in :term:`subdivision surface` meshes.

	Curve
	A type of object defined in terms of a line interpolated between Control Vertices.
	Available types of curves include :term:`B├⌐zier` and :term:`NURBS`.

	Cyclic
	Often referring to an object being circular. This term is often associated with :term:`Curve`.

	DOF
	Depth Of Field
	The distance in front of and behind the subject which appears to be in focus.
	For any given lens setting, there is only one distance at which a subject is precisely in focus,
	but focus falls off gradually on either side of that distance,
	so there is a region in which the blurring is tolerable.
	This region is greater behind the point of focus than it is in front,
	as the angle of the light rays change more rapidly; they approach being parallel with increasing distance.

	Diffuse Light
	Even, directed light coming off a surface.
	For most things, diffuse light is the main lighting we see.
	Diffuse light comes from a specific direction or location and creates shading.
	Surfaces facing towards the light source will be brighter,
	while surfaces facing away from the light source will be darker.

	Directional Light
	The light that has a specific direction, but no location.
	It seems to come from an infinitely far away source, like the sun.
	Surfaces facing the light are illuminated more than surfaces facing away, but their location does not matter.
	A Directional Light illuminates all objects in the scene, no matter where they are.

	Displacement Mapping
	Method for distorting vertices based on an image or texture.
	Similar to :term:`Bump Mapping`, but instead operates on the mesh's actual geometry.
	This relies on the mesh having enough geometry to represent details in the image.

	Double Buffer
	Technique for drawing and displaying content on the screen.
	Blender uses two buffers (images) to draw the interface in.
	The content of one buffer is displayed while drawing occurs on the other buffer.
	When drawing is complete, the buffers are switched.

	Edge
	Straight segment (line) that connects two :term:`vertices <vertex>`, and can be part of a :term:`face`.

	Edge Loop
	Chain of :term:`edges <edge>` belonging to consecutive :term:`quads <quad>`.
	An edge loop ends at a pole or a boundary. Otherwise, it is cyclic.

	Edge Ring
	Path of all :term:`edges <edge>` along a :term:`face loop` that share two faces belonging to that loop.

	Empty
	An :term:`Object` without any :term:`Vertices`, :term:`Edges <Edge>` or :term:`Faces <Face>`.

	Environment Map
	A method of calculating reflections.
	It involves rendering images at strategic positions and applying them as textures to the mirror.
	Now in most cases obsoleted by Raytracing, which though slower is easier to use and more accurate.

	Euler
	Euler Rotation
	Rotation method where rotations applied on each X, Y, Z axis component.

	Face
	Mesh element that defines a piece of surface. It consists of three or more :term:`edges <edge>`.

	Face Loop
	Chain of consecutive :term:`quads <quad>`.
	A face loop stops at a :term:`triangle` or :term:`N-gon` (which do not belong to the loop), or at a boundary.
	Otherwise, it is cyclic.

	Face Normal
	The normalized vector perpendicular to the plane that a :term:`face` lies in.
	Each face has its own normal.

	F-Curve
	A curve that holds the animation values of a specific property.

	Field of View
	The area in which objects are visible to the camera. Also see :term:`Focal Length <focal length>`

	Focal Length
	The distance required by a lens to focus collimated light.
	Defines the magnification power of a lens. Also see :term:`Field of View <field of view>`.

	FSAA
	Full-Screen Anti-Aliasing
	A method of :term:`Anti-aliasing` on the graphics card, so the entire image is displayed smooth.
	Also known as Multi-Sampling.

	This can be enabled in the :ref:`User Preferences <prefs-system-multi-sampling>`.
	On many graphics cards, this can also be enabled in the driver options.

	Gamma
	An operation used to adjust the brightness of an image.

	See also `Gamma correction <https://en.wikipedia.org/wiki/Gamma_correction>`__ on Wikipedia.

	Geometric Center
	The mean average of the positions of all vertices making up the object.

	Gimbal
	A pivoted support that allows the rotation of an object about a single axis.

	See also `Gimbal <https://en.wikipedia.org/wiki/Gimbal>`__ on Wikipedia.

	Gimbal Lock
	The limitation where axes of rotation can become aligned,
	losing the ability to rotate on an axis (typically associated with :term:`euler rotation`).

	- See also `Gimbal lock <https://en.wikipedia.org/wiki/Gimbal_lock>`__ on Wikipedia.
	- See also `Gimbal lock <https://blender.stackexchange.com/questions/469>`__ on Stackexchange.

	Global Illumination
	A superset of radiosity and ray tracing.
	The goal is to compute all possible light interactions in a given scene,
	and thus, obtain a truly photo-realistic image.
	All combinations of diffuse and specular reflections and transmissions must be accounted for.
	Effects such as color bleeding and caustics must be included in a global illumination simulation.

	Global Space
	See :term:`World Space`.

	Gouraud Shading
	Used to achieve smooth lighting on low-polygon surfaces without the
	heavy computational requirements of calculating lighting for each pixel.
	The technique was first presented by Henri Gouraud in 1971.

	Glossy Map
	See :term:`Roughness Map`.

	Head
	A subcomponent of a :term:`Bone`. The point of rotation for that :term:`Bone`.
	Has X, Y and Z coordinates measured in the :term:`Local Space` of the :term:`Armature` :term:`Object`.
	Used in conjunction with the :term:`Tail` to define the :term:`local <Local Space>` Y axis of the :term:`Bone`
	in :term:`Pose Mode`. The larger of the two ends when drawn as an :term:`Octahedron`.

	HDRI
	High Dynamic Range Image
	A set of techniques that allow a far greater dynamic range of exposures than normal digital imaging
	techniques. The intention is to accurately represent the wide range of intensity levels found in real scenes,
	ranging from direct sunlight to the deepest shadows.

	See also `HDRI <https://en.wikipedia.org/wiki/HDRI>`__ on Wikipedia.

	IOR
	Index Of Refraction
	A property of transparent materials.
	When a light ray travels through the same volume it follows a straight path.
	However, if it passes from one transparent volume to another, it bends.
	The angle by which the ray is bent can be determined by the IOR of the materials of both volumes.

	Interpolation
	Method of calculating new data between points of known value, like :term:`keyframes <keyframe>`.

	Inverse Kinematics
	The process of determining the movement of interconnected segments of a body or model.
	Using ordinary Kinematics on a hierarchically structured object you can, for example,
	move the shoulder of a puppet. The upper and lower arm and hand will automatically follow that movement.
	IK will allow you to move the hand and let the lower and upper arm go along with the movement.
	Without IK the hand would come off the model and would move independently in space.

	Keyframe
	A frame in an animated sequence drawn or otherwise constructed directly by the user.
	In classical animation, when all frames were drawn by animators,
	the senior artist would draw these frames, leaving the "in between" frames to an apprentice.
	Now, the animator creates only the first and last frames of a simple sequence (keyframes);
	the computer fills in the gap.

	Keyframing
	Inserting :term:`Keyframes <Keyframe>` to build an animated sequence.

	Lattice
	A type of object consisting of a non-renderable three-dimensional grid of vertices.

	See also :doc:`Lattice Modifier </modeling/modifiers/deform/lattice>`.

	Layer
	A device for organizing objects. See also :doc:`Layers </editors/3dview/object/properties/relations/layers>`.

	Local Space
	A 3D coordinate system that originates (for Objects) at the :term:`Object Origin`.
	or (for Bones) at the :term:`Head` of the :term:`Bone`.

	Compare to :term:`World Space`.

	Logic brick
	A graphical representation of a functional unit in Blender's game logic.
	A Logic brick can be a :term:`Sensor`, :term:`Controller` or :term:`Actuator`.

	Manifold
	Manifold meshes, also called water tight meshes,
	define a closed non-self-intersecting volume (see also :term:`non-manifold`).
	A manifold mesh is a mesh in which the structure of the connected
	faces in a closed volume will always point the normals (and there
	surfaces) to the outside or to the inside of the mesh without any overlaps.
	If you recalculate those normals, they will always point at
	a predictable direction (To the outside or to the inside of the volume).
	When working with non-closed volumes, a manifold mesh is a mesh in which
	the normals will always define two different and non-consecutive surfaces.
	A manifold mesh will always define an even number of non-overlapped surfaces.

	Matte
	Mask
	A grayscale image used to include or exclude parts of an image. A matte is
	applied as an :term:`Alpha Channel`, or it is used as a mix factor when
	applying :term:`Color Blend Modes`.

	Mesh
	Type of object consisting of :term:`vertices <vertex>`, :term:`edges <edge>` and :term:`faces <face>`.

	Micropolygons
	A polygon roughly the size of a pixel or smaller.

	MIP
	Mipmap
	Mipmapping
	'MIP' is an acronym of the Latin phrase 'multum in parvo', meaning 'much in little'.
	Mipmaps are progressively lower resolution representations of an image,
	generally reduced by half squared interpolations using antialiasing.
	Mipmapping is the procces used to calculate lower resolutions of the
	same image, reducing memory usage to help speed visualization, but increasing
	memory usage for calculations and allocation. Mipmapping is also a procces
	used to create small antialised samples of an image used for texturing.
	The mipmapping calculations are made by CPUs, but modern graphic processors
	can be selected for this task and are way faster.

	See the Mipmap option present in the :doc:`System Preferences </preferences/system>`.

	Motion Blur
	The phenomenon that occurs when we perceive a rapidly moving object.
	The object appears to be blurred because of our persistence of vision.
	Simulating motion blur makes computer animation appear more realistic.

	Multi-sampling
	See :term:`FSAA`.

	N-gon
	A :term:`face` that contains more than four :term:`vertices <vertex>`.

	Non-linear animation
	Animation technique that allows the animator to edit motions as a whole,
	not just the individual keys. Nonlinear animation allows you to combine,
	mix, and blend different motions to create entirely new animations.

	Non-manifold
	Non-Manifold meshes essentially define geometry which cannot exist in the real world.
	This kind of geometry is not suitable for several types of operations,
	especially those where knowing the volume (inside/outside) of the object is important
	(refraction, fluids, booleans, or 3D printing, to name a few).
	A non-manifold mesh is a mesh in which the structure of a
	non-overlapped surface (based on its connected faces) will not determine
	the inside or the outside of a volume based on its normals, defining
	a single surface for both sides, but ended with flipped normals.
	When working with non-closed volumes, a non-manifold mesh will always
	determine at least one discontinuity in the normal directions, either
	by an inversion of a connected loop, or by an odd number of surfaces.
	A non-manifold mesh will always define an odd number of surfaces.

	There are several types of non-manifold geometry:

	- Some borders and holes (edges with only a single connected face), as faces have no thickness.
	- Edges and vertices not belonging to any face (wire).
	- Edges connected to three or more faces (interior faces).
	- Vertices belonging to faces that are not adjoining (e.g. two cones sharing the vertex at the apex).

	See also: :ref:`Select Non-Manifold <mesh-select-non-manifold>` tool.

	Normal
	The normalized vector perpendicular to a surface.

	Normals can be assigned to vertices,
	faces and modulated across a surface using :term:`normal mapping`.

	Normal mapping
	Is similar to :term:`Bump mapping`, but instead of the image being a grayscale heightmap,
	the colors define in which direction the normal should be shifted,
	the three color channels being mapped to the three directions X, Y and Z.
	This allows more detail and control over the effect.

	NURBS
	A computer graphics technique for generating and representing curves and surfaces.

	Object
	Container for a type (Mesh, Curve, Surface, Metaball, Text, Armature,
	Lattice, Empty, Camera, Lamp) and basic 3D transform data (:term:`Object Origin`).

	Object Center
	Object Origin
	A reference point used to position, rotate, and scale an :term:`Object`
	and to define its :term:`Local Space` coordinates.

	Octahedron
	An eight-sided figure commonly used to depict the :term:`Bones <Bone>` of an :term:`Armature`.

	OpenGL
	The graphics system used by Blender (and many other graphics applications)
	for drawing 3D graphics, often taking advantage of hardware acceleration.

	See also `OpenGL <https://en.wikipedia.org/wiki/OpenGL>`__ on Wikipedia.

	Oversampling
	Is the technique of minimizing :term:`aliasing` when representing a high-resolution
	signal at a lower resolution.

	Also called Anti-Aliasing.

	Overscan
	The term used to describe the situation.
	when not all of a televised image is present on a viewing screen.

	See also `Overscan <https://en.wikipedia.org/wiki/Overscan>`__ on Wikipedia.

	Parent
	An :term:`Object` that affects its :term:`Child` objects.

	Parenting
	Creating a :term:`Parent`-:term:`Child` relationship between two :term:`objects <Object>`.

	Particle system
	Technique that simulate certain kinds of fuzzy phenomena,
	which are otherwise very hard to reproduce with conventional rendering techniques.
	Common examples include fire, explosions, smoke, sparks, falling leaves, clouds, fog, snow, dust,
	meteor tails, stars and galaxies, or abstract visual effects like glowing trails, magic spells.
	Also used for things like: fur, grass or hair.

	Phong
	Local illumination model that can produce a certain degree of realism in three-dimensional
	objects by combining three elements: diffuse, specular and ambient for each considered point on a surface.
	It has several assumptions -- all lights are points, only surface geometry is considered,
	only local modeling of diffuse and specular, specular color is the same as light color,
	ambient is a global constant.

	Pivot Point
	The pivot point is the point in space around which all rotations,
	scalings and mirror transformations are centered.

	See also the :doc:`Pivot Point </editors/3dview/object/transform/control/pivot_point/index>` docs.

	Pixel
	The smallest unit of information in a 2D raster image,
	representing a single color made up of red, green, and blue channels.
	If the image has an :term:`alpha channel`, the pixel will contain a corresponding fourth channel.

	Pole
	:term:`Vertex` where three, five, or more edges meet.
	A vertex connected to one, two, or four edges is not a pole.

	Pose Mode
	Used for :term:`posing`, :term:`keyframing`, :term:`weight painting`,
	:term:`constraining <Constraint>` and :term:`parenting` the :term:`bones <Bone>` of an :term:`armature`.

	Posing
	Moving, Rotating and Scaling the :term:`bones <Bone>` of an :term:`armature`
	to achieve an aesthetically pleasing pose for a character.

	Premultiplied Alpha
	See :term:`Alpha Channel`.

	Primitive
	A basic object that can be used as a basis for modeling more complicated objects.

	Procedural Texture
	Computer generated (generic) textures. Procedural textures can be configured via parameters.

	Projection
	In computer graphics, there are two common camera projections used.

	Perspective
	A perspective view is geometrically constructed by taking a scene in 3D
	and placing an observer at point O.
	The 2D perspective scene is built by placing a plane (e.g. a sheet of paper)
	where the 2D scene is to be drawn in front of point O,
	perpendicular to the viewing direction.
	For each point P in the 3D scene a PO line is drawn,
	passing by O and P. The intersection point S between
	this PO line and the plane is the perspective projection of that point.
	By projecting all points P of the scene you get a perspective view.
	Orthographic
	In an orthographic projection,
	you have a viewing direction but not a viewing point O. The line is then drawn
	through point P so that it is parallel to the viewing direction. The intersection
	S between the line and the plane is the orthographic projection of the point
	P.
	By projecting all points P of the scene you get the orthographic view.

	Quad
	Quadrilateral
	Quadrangle
	:term:`Face` that contains exactly four :term:`vertices <vertex>`.

	Quaternion
	Quaternion Rotation
	Rotation method where rotations are defined by four values (X, Y, Z and W).
	X, Y, and Z also define an :term:`axis`, and W an angle,
	but it is quite different from :term:`Axis Angle`.

	Radiosity
	A global lighting method.
	that calculates patterns of light and shadow for rendering graphics images from three-dimensional models.
	One of the many different tools which can simulate diffuse lighting in Blender.

	See also
	`Radiosity (computer graphics) <https://en.wikipedia.org/wiki/Radiosity_%28computer_graphics%29>`__
	on Wikipedia.

	Raytracing
	Rendering technique that works by tracing the path taken by a ray of light through the scene,
	and calculating reflection, refraction, or absorption of the ray whenever it intersects an object in the world.
	More accurate than :term:`scanline`, but much slower.

	Refraction
	The change in direction of a wave due to a change in velocity.
	It happens when waves travel from a medium with a given :term:`index of refraction` to a medium with another.
	At the boundary between the media, the wave changes direction;
	its wavelength increases or decreases but frequency remains constant.

	Render
	The process of computationally generating a 2D image from 3D geometry.

	Rig
	A system of relationships that determine how something moves. The act of building of such a system.

	Roll
	Roll Angle
	The orientation of the local X and Z axes of a :term:`Bone`.
	Has no effect on the local Y axis as local Y is determined by the location of the :term:`Head` and :term:`Tail`.

	Roughness Map
	A gray scale texture that defines how rough or smooth the surface of a material is.
	This may also be known as a :term:`Glossy Map`.

	Scanline
	Rendering technique. Much faster than :term:`raytracing`,
	but allows fewer effects, such as reflections, refractions, motion blur and focal blur.

	Sensor
	A :term:`logic brick` that acts like a sense of a lifeform. It reacts to touch, vision, collision etc.

	Shading
	Process of altering the color of an object/surface in the 3D scene,
	based on its angle to lights and its distance from lights to create a photorealistic effect.

	Smoothing
	Defines how :term:`faces <face>` are shaded.
	Face can be either solid (faces are rendered flat)
	or smooth (faces are smoothed by interpolating the normal on every point of the face).

	Specular light
	A light which is reflected precisely, like a mirror.
	Also used to refer to highlights on reflective objects.

	Straight Alpha
	See :term:`Alpha Channel`.

	Subsurface scattering
	Mechanism of light transport in which light penetrates the surface of a translucent object,
	is scattered by interacting with the material, and exits the surface at a different point.
	All non-metallic materials are translucent to some degree.
	In particular, materials such as marble, skin,
	and milk are extremely difficult to simulate realistically without taking subsurface scattering into account.

	Subdividing
	Technique for adding more geometry to a mesh.
	It creates new vertices on subdivided edges, new edges between subdivisions and new faces based on new edges.
	If new edges cross a new vertex is created at their crossing point.

	Subsurf
	Subdivision surface
	A method of creating smooth higher poly surfaces which can take a low polygon mesh as input.

	Sometimes abbreviated to Subsurf.

	See also
	`Catmull-Clark subdivision surface <https://en.wikipedia.org/wiki/Catmull%E2%80%93Clark_subdivision_surface>`__
	on Wikipedia.

	Tail
	A subcomponent of a :term:`Bone`. Has X, Y and Z coordinates measured in the :term:`Local Space`
	of the Armature Object. Used in conjunction with the :term:`Head`
	to define the :term:`local <Local Space>` Y axis of a :term:`Bone` in :term:`Pose Mode`.
	The smaller of the two ends when drawn as an :term:`Octahedron`.

	Tessellation
	The tiling of a plane using one or more geometric shapes usually resulting in :term:`Micropolygons`.

	Texture
	Specifies visual patterns on surfaces and simulates physical surface structure.

	Texture Space
	The bounding box to use when using Generated mapping to add a :term:`Texture` to an image.

	Timecode
	A coded signal on videotape or film giving information about the frame number, time of recording, or exposure.

	Title Safe
	Area of the screen visible on all devices.
	Place text and graphics inside this area to make sure they do not get cut off.

	Topology
	The arrangement of Vertices, Edges, and Faces which define the shape of a mesh.
	See :term:`vertex`, :term:`edge`, and :term:`face`.

	Transforms
	The combined idea of location, rotation and scale.

	Triangle
	:term:`Face` with exactly three :term:`vertices <vertex>`.

	UV map
	Defines a relation between the surface of a mesh and a 2D texture. In detail,
	each face of the mesh is mapped to a corresponding face on the texture.
	It is possible and often common practice to map several faces of the mesh to the same
	or overlapping areas of the texture.

	Vertex
	Vertices
	A point in 3D space containing a location. It may also have a defined color.
	Vertices are the terminating points of :term:`edges <edge>`.

	Vertex Group
	Collection of :term:`vertices <vertex>`.
	Vertex groups are useful for limiting operations to specific areas of a mesh.

	Voxel
	A cubicle 3D equivalent to the square 2D pixel.
	The name is a combination of the terms "Volumetric" and ":term:`Pixel <pixel>`".
	Used to store smoke and fire data from physics simulations.

	Walk Cycle
	In animation, a walk cycle is a character that has just the walking function animated.
	Later on in the animation process the character is placed in an environment
	and the rest of the functions are animated.

	Weight Painting
	Assigning :term:`vertices` to :term:`Vertex Groups <Vertex Group>` with a weight of 0.0 - 1.0.

	World Space
	A 3D coordinate system that originates at a point at the origin of the world.
	Compare to :term:`Local Space`.

	Z-buffer
	Raster-based storage of the distance measurement between the camera and the surface points.
	Surface points which are in front of the camera have a positive Z value and
	points behind have negative values. The Z-Depth map can be visualized as a grayscale image.
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