School of Computer Science & Information Technology

School of Computer Science & Information Technology

G6DPMM - Lecture 15G6DPMM - Lecture 15

Media Design III – Video & AnimationMedia Design III – Video & Animation

Perception of VideoPerception of Video Changes in sensory input tend to be instantly Changes in sensory input tend to be instantly

noticeablenoticeable Changes in background sound (e.g. cessation)Changes in background sound (e.g. cessation) Unexpected movementUnexpected movement Motion in peripheral visionMotion in peripheral vision

Fundamental biological imperativeFundamental biological imperative Danger Danger OpportunityOpportunity

Motion is the strongest such imperativeMotion is the strongest such imperative Video is both effective and has a high cognitive Video is both effective and has a high cognitive

costcost

Change & MovementChange & Movement

ChangeChange A sensory property becomes different over timeA sensory property becomes different over time For example –visual propertiesFor example –visual properties

Colour, size, positionColour, size, position

MovementMovement A type of change involving positionA type of change involving position

AnimationAnimation A type of movement that is synthetic (e.g. generated A type of movement that is synthetic (e.g. generated

by computer, cell drawing, etc.)by computer, cell drawing, etc.)

Increasing use of VideoIncreasing use of Video

Video is becoming increasingly used in multimediaVideo is becoming increasingly used in multimedia Technically more feasible (i.e. cheaper)Technically more feasible (i.e. cheaper) Increasing bandwidth on networksIncreasing bandwidth on networks

This may or may not be a good thing!This may or may not be a good thing! Very powerful media for conveying conceptsVery powerful media for conveying concepts Is it being used for conveying useful concept?Is it being used for conveying useful concept?

The (cognitive) power of video is the danger!The (cognitive) power of video is the danger! Video grabs attention like no other mediaVideo grabs attention like no other media If the message is trivial or If the message is trivial or mundane mundane this is a very bad thing!this is a very bad thing!

Video AbuseVideo Abuse Video is becoming increasingly used in multimediaVideo is becoming increasingly used in multimedia

Technically more feasible (i.e. cheaper)Technically more feasible (i.e. cheaper) Increasing bandwidth on networksIncreasing bandwidth on networks

This may or may not be a good thing!This may or may not be a good thing! Very powerful media for conveying conceptsVery powerful media for conveying concepts Is it being used for conveying useful concept?Is it being used for conveying useful concept?

The (cognitive) power of video is the danger!The (cognitive) power of video is the danger! Video grabs attention like no other mediaVideo grabs attention like no other media If the message is trivial or If the message is trivial or mundane mundane this is a very bad thing!this is a very bad thing!

Appropriate videoAppropriate video Only use if there is Only use if there is nono other way to convey the message other way to convey the message

Use video sparinglyUse video sparingly

Data budget / experience trade-offData budget / experience trade-off High quality is desirableHigh quality is desirable BUT – data budget implicationsBUT – data budget implications

Length of clipLength of clip Clarity of imageClarity of image Resolution of image (i.e. size)Resolution of image (i.e. size) Frame rateFrame rate

How high quality to you How high quality to you needneed?? Depends upon applicationDepends upon application Some (e.g. medical) need very high qualitySome (e.g. medical) need very high quality Medium quality might be acceptable (sports)Medium quality might be acceptable (sports) Lower quality might be acceptable (e.g. talking head)Lower quality might be acceptable (e.g. talking head)

Data budget / experience trade-offData budget / experience trade-off High quality is desirableHigh quality is desirable BUT – data budget implicationsBUT – data budget implications

Length of clipLength of clip Clarity of imageClarity of image Resolution of image (i.e. size)Resolution of image (i.e. size) Frame rateFrame rate

How high quality to you How high quality to you needneed?? Depends upon applicationDepends upon application Some (e.g. medical) need very high qualitySome (e.g. medical) need very high quality Medium quality might be acceptable (sports)Medium quality might be acceptable (sports) Lower quality might be acceptable (e.g. talking head)Lower quality might be acceptable (e.g. talking head)

Placing the videoPlacing the video Placing video on screenPlacing video on screen

Provide video with its own Provide video with its own area on screenarea on screen

Provide video with its own Provide video with its own video playing contextvideo playing context

The context may be the The context may be the entire screenentire screen

Linking to videoLinking to video Don’t hide linksDon’t hide links Make it obvious that it is a Make it obvious that it is a

video linkvideo link

Video context (1)

Video context (2)

Video & NarrativeVideo & Narrative

Videos have their own paceVideos have their own pace To a greater or lesser extent, control is removed To a greater or lesser extent, control is removed

from the userfrom the user This can disrupt narrativeThis can disrupt narrative Done deliberatelyDone deliberately

Takes over the users attention to focus on an Takes over the users attention to focus on an important pointimportant point

Done badlyDone badly User feels disempowered and frustrated User feels disempowered and frustrated Leads to annoyance or loss of attentionLeads to annoyance or loss of attention

Video ControlsVideo Controls

Important for empowering a userImportant for empowering a user BUT – too many inappropriate controls are confusingBUT – too many inappropriate controls are confusing A common mistake is to include all possible controlsA common mistake is to include all possible controls What is the users motivation for watching the video?What is the users motivation for watching the video?

Automatic playAutomatic play In page video – very bad practice (user out of control)In page video – very bad practice (user out of control) Unique context – might be acceptable, depending Unique context – might be acceptable, depending

upon complexity of contextupon complexity of context

Play / Stop buttonPlay / Stop button Addresses the problem of automatic playAddresses the problem of automatic play Provides a quick exit routeProvides a quick exit route

Within video navigationWithin video navigation Full video controlsFull video controls

Slow motion (varying speeds)Slow motion (varying speeds) Rewind (varying speeds)Rewind (varying speeds) Reverse (NB problems with some codecs)Reverse (NB problems with some codecs) Single frame stepSingle frame step Frame numbers / jumpFrame numbers / jump Chapter-based navigationChapter-based navigation User defined bookmarksUser defined bookmarks

Are these needed?Are these needed? Some applications (e.g. sports) need more than play/stopSome applications (e.g. sports) need more than play/stop Long clips have different requirements from short onesLong clips have different requirements from short ones Probably technical multimedia applications (e.g. video editing) Probably technical multimedia applications (e.g. video editing)

need this full rangeneed this full range Controls don’t need to be permanent (e.g. advanced mode)Controls don’t need to be permanent (e.g. advanced mode)

Link Labelling & InterruptionLink Labelling & Interruption Never force users to watch video they don’t wantNever force users to watch video they don’t want

The longer the clip the more important this rule isThe longer the clip the more important this rule is

Design dilemma – link labelling can interrupt Design dilemma – link labelling can interrupt narrative flownarrative flow

Either:Either: Warn the user about a video before they view it Warn the user about a video before they view it

(link labelling)(link labelling)

oror Allow an easy way out of the video Allow an easy way out of the video

(interruption)(interruption)

Minimize video usageMinimize video usage Break large clips down into small clipsBreak large clips down into small clips

Must be under full controlMust be under full control Preview clips may be usefulPreview clips may be useful Does this affect narrative flow?Does this affect narrative flow?

Video introductionVideo introduction Video “scene-setting” sequence followed by other mediaVideo “scene-setting” sequence followed by other media

Audio onlyAudio only Voice is often as effective as a “talking head”Voice is often as effective as a “talking head”

Images and AudioImages and Audio Commented slideshowCommented slideshow

““Foreign correspondent” styleForeign correspondent” style Audio speech with still picture of person speakingAudio speech with still picture of person speaking Various other media as neededVarious other media as needed

Animation in DesignAnimation in Design

Types of animationTypes of animationMoving still objects along pre-defined pathsMoving still objects along pre-defined pathsChanging shapes of objectsChanging shapes of objects

““tweening”tweening”

Frame (cell) based animationFrame (cell) based animationAnimating wire-frame modelsAnimating wire-frame models

Representation of movementRepresentation of movementMovement may be hinted at – even in still images Movement may be hinted at – even in still images

Use of AnimationUse of Animation

Most of the guidelines for using video applyMost of the guidelines for using video applyAnimation is cognitively powerfulAnimation is cognitively powerfulUse sparingly and with good reasonUse sparingly and with good reasonBeware of animation in cheap clip-art Beware of animation in cheap clip-art

librarieslibrariesPutting free animated gifs on your web pages is Putting free animated gifs on your web pages is

usually a very bad mistake!usually a very bad mistake!

Because movement is powerful very subtle Because movement is powerful very subtle animations are often the most effectiveanimations are often the most effective

Cartoon PhysicsCartoon Physics

Animation in multimedia is about Animation in multimedia is about communicating concepts, communicating concepts, notnot modelling the modelling the worldworld

Animations should behave the way people think Animations should behave the way people think that they will – not the way they really willthat they will – not the way they really will

Cartoons exaggerate this behaviour – this sort Cartoons exaggerate this behaviour – this sort of exaggeration can be useful in making a pointof exaggeration can be useful in making a point