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Programming With QuickTime VR
Programming With QuickTime VR
action See movie controller action.
action filter function An application-defined function that is called by a movie controller component each time the component receives a movie controller action. Your filter function can handle the action itself or refer it back to the movie controller component for processing .
angular unit A unit for measuring angles. For the QuickTime VR Manager, the default angular unit is degrees. Compare degree, radian.
animation See frame animation, view animation.
animation setting A value that specifies characteristics of an object node while it is playing an animation. For example, one animation setting determines whether an object node animation is looped. Compare control setting.
antialiasing The smoothing of jagged edges on a displayed shaped by modifying the transparencies of individual pixels along the shape's edge.
API See application programming interface.
application programming interface (API) The total set of constants, data structures, routines, and other programming elements that allow developers to use some part of the system software.
area of interest structure A data structure that delineates a rectangular area in the back buffer. Defined by the AreaOfInterest data type.
atom The basic unit of data in a movie resource. Defined by the QTAtom data type. There are a number of different atom types, including movie atoms, track atoms, and media atoms. There are two varieties of atoms: container atoms, which contain other atoms, and leaf atoms, which do not contain any other atoms.
atom container An opaque object that contains one or more atoms. Defined by the QTAtomContainer data type.
author (v) To create a multimedia title, such as a QuickTime VR movie. (n) The person or persons who creates a multimedia title.
autoscrolling The scrolling that occurs when the mouse button is being held down and the user is zooming.
back buffer An image buffer maintained by QuickTime VR for panoramic nodes that contains an image that has not yet been corrected. Compare prescreen buffer.
back buffer imaging procedure An application-defined procedure that is executed at established times; you use this procedure to access the back buffer. Compare prescreen buffer imaging completion procedure.
base resolution The highest resolution image present in a node.
constraint See viewing constraint.
container atom A QuickTime atom that contains other atoms, possibly including other container atoms. Examples of container atoms are track atoms and edit atoms. Compare leaf atom.
controller See movie controller component, QuickTime VR movie controller.
controller bar A rectangular region associated with a QuickTime VR movie that displays the movie's controls.
controller bar key A key that, when pressed, activates a control in the controller bar. For example, the translation key is a controller bar key.
control setting A value that specifies whether an object can wrap during panning and tilting, as well as other features of the node. Compare animation setting.
correct To undo the cylindrical (or other) projection of a panoramic image so that it appears as it was originally captured or rendered. Also called warp .
correction mode The kind of warping correction to be applied when imaging a panoramic view.
current node The node in a scene that is currently being viewed on the screen.
cursor record A data structure that indicates which cursor to replace and its replacement cursor. Defined by the CursorRecord data type.
custom hot spot A hot spot of a type defined by a third-party developer.
custom hot spot cursor A custom cursor that is displayed during interaction with a hot spot.
cylindrical projection A method of projecting a panorama onto the surface of a cylinder.
default node The node in a scene that is displayed when the scene is first opened.
degree An angular unit equal to 1/360 of a complete circle. Indicated by the sign °. Compare radian.
destination node The node to which a link hot spot is linked.
dicing The process of transforming a panoramic image into individual frames in a panorama image track.
enviromapping The process of projecting an image onto the inside of a shape, such as a sphere or cylinder.
field of view The horizontal or vertical angular expanse visible through a camera.
field-of-view constraint atom An atom in a QuickTime VR file that contains information about the initial vertical field of view constraints for a panorama. Compare pan constraint atom, tilt constraint atom.
floating-point point structure A data structure used to specify a point in a panorama or object. Defined by the FloatPoint data type.
frame animation An animation through all frames of a particular view. Compare view animation.
frame animation rate See frame rate.
frame differencing A form of temporal compression that involves examining redundancies between adjacent frames in a moving image sequence.
frame rate The rate at which the frame animation in a view is played. Compare view rate.
front buffer See prescreen buffer.
full panorama A 360-degree panorama . Compare partial panorama.
go-back button A button in the controller bar for panoramas that allows the user to return to the previous node.
horizontal field of view The horizontal angular expanse visible through a camera. Compare vertical field of view.
hot spot An area in a QuickTime VR movie that permits user interaction.
hot spot action selector A value passed to a mouse over hot spot procedure that indicates whether the cursor has entered, is in, or has left the hot spot.
hot spot atom An atom in a QuickTime VR file that contains information about a hot spot. A hot spot atom is always a child of a hot spot parent atom.
hot spot callback routine See mouse over hot spot procedure.
hot spot display button A button in the controller bar that allows the user to highlight the visible hot spots.
hot spot ID An unsigned long integer that uniquely identifies a hot spot.
hot spot image track A video track in a QuickTime VR file that contains colored regions depicting the hot spots. For objects, an image in the hot spot image track must be synchronized in time to the corresponding image in the object image track.
hot spot parent atom An atom in a QuickTime VR file that contains one or more hot spot atoms and their children.
hysteresis See mouse-click hysteresis.
Image Compression Manager The part of QuickTime that provides image compression and decompression services.
image track See low-resolution image track, object image track, panorama image track.
imaging atom An atom in a QuickTime VR file that describes the default imaging characteristics for one type of node in a scene. Imaging atoms are contained in an imaging parent atom. See also panorama-imaging atom.
imaging mode A mode or state of a panoramic node that determines the kind of drawing that is to be performed for the node.
imaging parent atom An atom in a QuickTime VR file that contains one or more imaging atoms.
imaging property A property of a node that determines a drawing characteristic for that node (such as the image quality).
instance See QuickTime VR movie instance.
interaction property A property of a QuickTime VR movie whose value determines a specific mode of user interaction.
intercept procedure A function, installed by a call to QTVRInstallInterceptProc , that is executed instead of (or in addition to) a QuickTime VR Manager function.
intercept selector A constant that indicates which QuickTime VR Manager function to intercept. Defined by the QTVRProcSelector enumerated constants.
intercept structure A data structure used to pass information to an intercept procedure. Defined by the QTVRInterceptRecord data type.
key node An important node in a scene.
label display area An area in the controller bar in which information can be displayed. For instance, when the cursor is over one of the buttons, the button's name appears in the label display area.
leaf atom A QuickTime atom that contains no other atoms. Compare container atom.
link A connection between two nodes in a QuickTime VR movie.
link hot spot A hot spot that allows a user to navigate from one node in a scene to another.
lossless compression A compression scheme that preserves all of the original data.
low-resolution image track A video track that contains a diced low-resolution version of a panoramic image.
mouse-click hysteresis The distance, in pixels, from the location of a mouse-down event to the limit in which the cursor is considered not to have moved.
mouse-click timeout The number of ticks after which a mouse click times out and is automatically switched from a hot spot selection into a pan.
mouse-down tracking The process of tracking the state of the mouse button when it is clicked in a QuickTime VR movie. Compare mouse-over tracking.
mouse-motion scale A value that indicates the number of degrees or radians that an object or panorama is panned or tilted when the cursor is dragged the entire width of the VR movie image.
mouse over hot spot procedure An application-defined procedure that is executed whenever the cursor moves over, remains above, or leaves a hot spot.
mouse-over tracking The process of tracking the location of the cursor when it is in a QuickTime VR movie and changing the shape of the cursor as appropriate. Compare mouse-down tracking.
movie A set of time-based data that is managed by the Movie Toolbox. A QuickTime movie may contain sound, video, animation, laboratory results, financial data, or a combination of any of these types of time-based data. A QuickTime movie contains one or more tracks; each track represents a single data stream in the movie.
movie controller See movie controller component, QuickTime VR movie controller.
movie controller action A constant (of type mcAction ) used by QuickTime movie controller components in the MCDoAction function. Applications that include action filters can receive any of these actions.
movie controller component A component that manages the user interface for playing and editing movies.
movie image The image currently displayed in a QuickTime VR movie.
movie instance See QuickTime VR movie instance.
multinode movie A QuickTime VR movie that includes more than one node. Compare single-node movie.
navigable node See object node.
node A position in a scene at which you view an object or a panorama.
node-entering procedure An application-defined procedure that is executed each time the user enters a node. Compare node-leaving procedure.
node header atom An atom in a QuickTime VR file that contains the type and ID of a node, as well as the node name and any node comments.
node ID An unsigned long integer that uniquely identifies a node in a movie.
node ID atom An atom in a QuickTime VR file that specifies the ID of a node in the scene. Each node ID atom has a single child, which is a node location atom.
node information atom container An atom container that contains information about a particular node in a scene (for example, the hot spots and default characteristics of the node).
node-leaving procedure An application-defined procedure that is executed each time the user leaves a node. Compare node-entering procedure.
node location atom An atom in a QuickTime VR file that specifies the type and location of a node.
node parent atom An atom in a QuickTime VR file that contains one or more node ID atoms.
nudge To move to the next available view in a specified direction.
nudge control A constant that indicates the direction in which to nudge.
object (1) The real or synthetic object that is captured photographically or rendered by computer to create an object node. (2) See object node.
object image array A two-dimensional array of images that represent all possible views of an object.
object image track A video track in a QuickTime VR movie file that contains, in sequential order, the views of an object .
object node A type of node that allows a user to manipulate a photographically captured or computer-rendered object. Compare panoramic node.
object sample atom An atom in a QuickTime VR file that describes a single object.
object track A track that contains information about the object nodes in a scene. Compare panorama track.
object view A single set of values for the field of view, view center, pan angle, and tilt angle for an object node. Compare panorama view.
palindrome looping A type of looping in which the frames in a view duration are played forward, then backward, then forward, and so on.
pan To move a camera or point of view horizontally. Compare tilt.
pan angle The angle of pan. Pan angles are measured in radians or degrees, where positive values pan to the left. Compare tilt angle.
pan constraint atom An atom in a QuickTime VR file that contains information about the initial pan angle constraints for a panorama. Compare field-of-view constraint atom, tilt constraint atom.
panning speed The relative speed of panning and tilting. This speed should be from 1 (the slowest speed) through 10 (the fastest speed); the default panning and tilting speed is 5.
panorama (1) The real or synthetic expanse that is captured photographically or rendered by computer to create a panoramic node. (2) See panoramic node.
panorama buffer See back buffer.
panorama data atom See panorama sample atom.
panorama image track A video track in a QuickTime VR movie file that contains the diced frames of the original panoramic image .
panorama-imaging atom An atom in a QuickTime VR file that describes the default imaging characteristics for the panoramic nodes in a scene.
panorama sample atom An atom in a QuickTime VR file that describes a single panorama, including information about the default viewing angles and the source panoramic image.
panorama track A track that contains information about the panoramic nodes in a scene. Compare object track.
panorama view A single set of values for the field of view, pan angle, and tilt angle for a panoramic node. Compare object view.
panoramic image A cylindrical band of blended photographed or rendered images. Also called a panoramic PICT .
panoramic node A type of node that allows a user to view a panorama. Compare object node.
panoramic PICT See panoramic image.
partial panorama A panorama that is less than 360 degrees. Compare full panorama.
play flag See animation setting, control setting.
play rate The rate (and direction) at which a movie is played.
play setting See animation setting, control setting.
prescreen buffer An image buffer maintained by QuickTime VR for panoramic nodes that contains the corrected image. Also called the front buffer . Compare back buffer.
prescreen buffer imaging completion procedure An application-defined procedure that is executed each time QuickTime VR is finished drawing an image into the prescreen buffer. Compare back buffer imaging procedure.
procedure selector See intercept selector.
QTVR instance See QuickTime VR movie instance.
QTVR movie See QuickTime VR movie.
QTVR track A track in a QuickTime VR movie that contains a list of the nodes in the scene and other information about the scene.
QuickTime A part of the system software for Macintosh and other computers that an application can use to control time-based data, such as video or audio data.
QuickTime movie A set of time-based data that can be displayed and manipulated using QuickTime.
QuickTime VR An extension of the QuickTime technology developed by Apple Computer, Inc. that allows users to interactively explore and examine photorealistic, three-dimensional virtual worlds.
QuickTime VR file format The format of the movie files that contain QuickTime VR movies.
QuickTime VR Manager The part of the system software for Macintosh and other computers that an application can use to control QuickTime VR movies.
QuickTime VR movie A collection of object and panoramic nodes.
QuickTime VR movie controller The movie controller component that manages QuickTime VR movies. See also controller bar.
QuickTime VR movie instance An instance of a QuickTime VR movie. Defined by the QTVRInstance data type.
radian An angular unit defined by the circular angle whose radius is equal to the subtended circular arc. Abbreviated rad. A radian is 57.2958 degrees. Compare degree.
scene (1) A site or location at which you want to make a QuickTime VR movie. (2) A collection of one or more nodes.
scene header atom See VR world header atom.
sibling atom An atom that has the same parent as some other atom (that is, is contained in the same container).
single-node movie A QuickTime VR movie that includes just one node. Compare multinode movie.
spatial compression Image compression that is performed in the context of a single frame. This compression technique takes advantage of redundancy in the image to reduce the amount of data that is required to accurately represent the image. Compare temporal compression.
speaker button A button in the controller bar that allows the user to adjust the sound volume.
string atom An atom in a QuickTime VR file that contains a string.
swing transition A smooth motion from one view in a node to another view in the same node.
synthetic Not real, as for example the objects in a computer-generated three-dimensional model.
temporal compression Image compression that is performed between frames in a sequence. This compression technique takes advantage of redundancy between adjacent frames in a sequence to reduce the amount of data that is required to accurately represent each frame in the sequence. Sequences that have been temporally compressed typically contain key frames at regular intervals. Compare spatial compression.
tilt To move a camera or point of view vertically. Compare pan.
tilt angle The angle of tilt. Tilt angles are measured in radians or degrees, where positive values tilt up. Compare pan angle.
tilt constraint atom An atom in a QuickTime VR file that contains information about the initial tilt angle constraints for a panorama. Compare field-of-view constraint atom, pan constraint atom.
tilting speed The relative speed of panning and tilting. This speed should be from 1 (the slowest speed) through 10 (the fastest speed); the default panning and tilting speed is 5.
timeout See mouse-click timeout.
transition The movement between two items in a movie, such as from one view in a node to another view in the same node, or from one node to another.
transition effect Any special visual effect associated with a transition.
transition property A property of a VR movie whose value determines a specific kind of transition effect.
translate To reposition an object by changing the current view center.
translate mode An interaction property for objects whose value determines whether dragging the mouse causes an object to be translated ( true ) or to be panned or tilted ( false ).
translate mode button A button in the controller bar that allows the user to enable or disable translate mode.
translation key The key on a keyboard that the user can hold down to enable translate mode.
Universal Resource Locator (URL) An address of a page on the World Wide Web.
URL See Universal Resource Locator.
URL hot spot A hot spot that is associated with a URL.
user data Auxiliary data that your application can store in a QuickTime movie, track, or media structure. The user data is stored in a user data list; items in the list are referred to as user data items . Examples of user data include a copyright, date of creation, name of a movie's director, and special hardware and software requirements.
user data item A single element in a user data list.
user data list The collection of user data for a QuickTime movie, track, or media structure.
vertical field of view The vertical angular expanse visible through a camera. Compare horizontal field of view.
view See object view, panorama view.
view angle See pan angle, tilt angle.
view animation An animation through all views in the current row of a particular object. Compare frame animation.
view animation rate See view rate.
view array See object image array.
view center The pixel in the image of a view that appears at the center of an object's bounding box.
view duration The amount of time in an object node's video track that is occupied by a particular view of an object.
viewing constraint A limit on the current viewing characteristics (pan angle, tilt angle, or field of view) for a panorama or object. A constraint is imposed at runtime and must always lie in the node's viewing limits. Compare viewing limit.
viewing constraint atom An atom in a QuickTime VR file that contains information about the initial viewing constraints for a panorama. Compare field-of-view constraint atom, pan constraint atom, tilt constraint atom.
viewing limit A physical limit on the allowable viewing characteristics (pan angle, tilt angle, or field of view) for a panorama or object. A viewing limit is imposed by the panoramic or object data stored in the movie file. Compare viewing constraint.
view rate The rate at which the view animation in an object is played. Compare frame rate.
view setting See control setting.
view state A state that selects an alternate set of images for an object's views. For instance, holding down the mouse button might change an object from one view state to another, causing a different set of images to be displayed.
virtual reality (VR) The experience of exploring and interacting with a spatial environment using a computer.
virtual world A spatial environment that can by explored and interacted with using a computer.
VR See QuickTime VR, virtual reality.
VR movie See QuickTime VR movie.
VR movie instance See QuickTime VR movie instance.
VR panorama See panoramic node.
VR world (1) See virtual world. (2) A data structure that contains general information about a QuickTime VR movie. A movie's VR world is contained in the QTVR track's sample description header, defined by the QTVRSampleDescription data type.
VR world header atom An atom in a QuickTime VR file that contains the name of the scene and the default node ID to be used when the file is first opened.
warping correction mode See correction mode.
warp space buffer See back buffer.
zoom To enlarge or reduce the magnification of an image while maintaining the current point of interest.
zoom-in button A button in the controller bar that allows the user to zoom in.
zooming speed The relative speed of zooming in and out. This speed should be from 1 (the slowest speed) through 10 (the fastest speed); the default zooming speed is 5.
zoom-out button A button in the controller bar that allows the user to zoom out.