# XR Midterm Cram Sheet

## XR fundamentals

- **UX** = whole end-to-end experience; **UI** = one interface layer inside UX.
- XR has no mainstream precursor like the phone; adoption needs useful, learnable, comfortable experiences.
- Smart products work when technology fits a user's lifestyle/ecosystem.
- Mobile influences: icons, menus, tap, scroll, pinch, zoom, long-press.
- Games influence: physics, tactile actions, controllers, two hands, inventories, progression.
- XR combines both with spatial gaze/hand/voice/body input and may use ambient sensing.

## AR essentials

- AR scene basics: **physical target + augmenting visuals + event sequence**.
- Interactive AR adds **interactable surface + goals/rewards**.
- Anchors: **surface, face, image/marker, 3D object**.
- **World space** is 3D/environment-relative; **screen space** is device/display UI.
- **Occlusion** makes real/virtual depth ordering believable.
- Interaction pattern: **trigger → event → response**.
- Scene = objects + anchors + sensing + interaction + animation + exit; an experience may sequence multiple scenes.
- **ARKit** senses/reads environment; **RealityKit** integrates/interacts with 3D objects (Apple examples).
- AR examples: furniture placement, product try-on/configuration, mountain/star identification, manuals, HUDs, logistics, themed rides.

## AR 3.0

- **Persistence**: content stays associated with a real place across time/users.
- **SLAM**: simultaneous localization and mapping.
- **VPS/depth**: more accurate positioning and alignment.
- **Absolute scale**: product appears at its actual size.
- **Real-world collider**: sensed physical object affects virtual-object interaction.

## Device distinctions

- **Optical see-through**: user directly sees real world through lens (Specs).
- **Video pass-through**: camera image shown on headset displays (Quest/Vision Pro examples).
- Specs: on-the-go, community-oriented companion; Quest/AVP: living-room/workplace, richer spatial display/immersive use.
- 360 video: can look realistic, little interaction. Realtime VR: interactive, usually stylized.
- Week 3 AR/MR rule of thumb: roughly **80% physical world** remains visible.

## Vision Pro and creators

- Content: **windowed apps; Full Space; Apple Immersive Video; multi-app bounded volumes; pop-in/pop-out window-to-immersion**.
- Dev stacks: **Xcode + Reality Composer Pro; Unity PolySpatial; Godot SDK; WebXR (A-Frame, three.js) in Safari**.
- Tool innovations: virtual laptop display, real-world collision, space-aware scaling, voice + hands.

## UX + rich experiences

- **Immersive** = senses/presence; **Experiential** = unusual, positive presence/body/environment; **Engaging** = interactive/memorable; **Narrative** = purpose/progression; **Spatial** = tied to physical context/movement.
- Week 6 slide visibly lists five attributes although study-guide text says four: learn all five.
- UX design areas: comfort/safety; affordance/signifier/feedback; environment/space; sensory input; engagement/story; constraints; inclusion/accessibility.
- Onboarding: small steps, familiar cues, preview the world, positive moment early.
- Rich XR markets: travel/recreation; personalized sports; movies/games; location entertainment; physical health; remote work; experiential marketing.

## Curated experience and rewards

- Six stages: **Anticipation → Onboarding → Doing → Transition → Completing → Reflection**.
- Core loop repeats within Doing: **action → feedback/reward → next action**.
- Rewards: **Autonomy** (choice), **Competence** (mastery), **Relatedness** (connection), **Reciprocity** (mutual exchange/contribution).
- Expressive/game avatar = play/identity/social expression. Realistic Persona = recognizable presence for work/family/shared activities.

## Vision Pro setup/navigation

- Eye calibration: look at a dot; pinch index finger + thumb to confirm.
- **Eyes target; pinch confirms.**
- Look at right palm to bring up app view; turn hand over for Control Center.
- Crown re-centers Home Screen; pinch/grab line moves window; corner handle scales; X closes.

## Reading takeaways

- UX is holistic; UI is not all of UX. XR UX connects user research to 3D/game-engine constraints.
- AR types: **marker-based** (pattern/image), **markerless** (mapping/SLAM), **location-based** (geographic position); projection AR is installation-based.
- Spatial UX must consider viewing angle/distance, lighting/shadows, object state, safety, comfort, privacy, accessibility.
- Empathy map: **Says / Thinks / Does / Feels**.
- Handheld AR: environment context, safety, off-screen cues, simple familiar interaction, light/shadow cues, device comfort.
- AR social object can be “the app”; animation and material cues convey state and fit.

## Exam cue

Course midterm: about 35 mixed short-paragraph and multiple-choice questions; closed book; 60 maximum points. Practice explaining a concept with a definition **and** a concrete example.