# Perception Decisions

How the player observes and interacts with the world: camera, fog, line-of-sight, sound, monologue, perception modes.

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### D-011: Fog of perception is non-negotiable (Pillar 1 infrastructure)
- **Date:** 2026-02-09
- **Decision:** Fog of perception is not a feature - it's the minimum requirement for information asymmetry to work with a top-down camera. Without it, the player is omniscient within their viewport and the entire information pillar collapses at the local map level. First-person camera gets this for free; top-down must enforce it.
- **Implementation:** Line-of-sight based (shadowcasting), not simple radius. Walls block vision, buildings are opaque, corners create blind spots, z-levels interact with sightlines.
- **Sound as secondary information channel:** Events outside LOS can be heard - footsteps, conversations, gunfire, alarms. Sound gives partial/directional information, prompting decisions based on incomplete data.
- **Applies to ALL entities:** NPCs use the same LOS/perception system as the player. An NPC who can't see you doesn't know you're there. NPCs have memory and inference (saw you enter a building → knows you're inside). Ties to [D-010](architecture.md#d-010-multiplayer-ready-architectural-baseline) principle 2: information boundaries are universal, the player's isn't special.
- **Fog returns when you leave:** Previously explored areas revert to fog over time. Information about locations decays. What you saw at the docks yesterday may not be true today.
- **v0.1 scope:** 2D shadowcast per z-level + sound propagation. Vertical LOS (looking between floors) deferred.
- **Rationale:** Team Leader identified overnight that top-down without fog is a fundamental gap in the information asymmetry design.
- **Raised by:** Team Leader (Jeroen), with technical framing by Tyre and Gestalt.

### D-015: Camera locked to character, rotation as future option
- **Date:** 2026-02-09
- **Decision:** Camera is locked to the character at all times. No panning. Optionally rotates to character facing direction (player option, later version).
- **Rationale:** Pannable camera breaks the information model - you become a surveillance drone, not a character. Locked camera reinforces "you ARE this person." Rotation with facing direction restores directional audio mapping (binaural becomes viable again) and creates a natural vision cone (front = detailed, peripheral = reduced, behind = blind).
- **Vision cone model:**
  - Forward: full LOS, full detail
  - Peripheral: reduced range, dimmer
  - Behind: fog / blind spot. You can be snuck up on.
- **Reference:** Hotline Miami's camera made that game terrifying with the same principle.
- **v0.1:** Locked camera, no rotation. Vision cone still works on fixed-north map. Rotation deferred as player option.
- **Raised by:** Team Leader (Jeroen).

### D-016: Internal monologue as core perception/atmosphere system
- **Date:** 2026-02-09
- **Decision:** The player character has an internal monologue that narrates sensory information the camera can't show, creates atmosphere, provides diegetic hints, and can be an unreliable narrator.
- **Functions:**
  - **Perception bridge:** Translates non-visual senses into character voice. *"Footsteps behind me. Two people, unhurried."*
  - **Atmosphere:** Character's running commentary on environment, mood, situation.
  - **Diegetic tutorial:** Character thinks about what they might do. *"That terminal might have access logs."* No "press X" popups.
  - **Unreliable narrator:** Monologue is character's INTERPRETATION, not ground truth. Can be wrong. *"Seems quiet. Safe to move."* (It wasn't safe.)
  - **Character voice:** Varies by character background, mood, knowledge. Paranoid Guardian vs confident Senator walking the same street = different monologue = different experience.
- **Production note (Nigel):** Cheapest feature on the list - it's text. Thousands of contextual lines, AI-assistable generation, character-specific variants.
- **Raised by:** Emerged from team discussion. Tyre proposed text/log as sound option, team recognized broader potential.

### D-017: Perception modes as character-build system
- **Date:** 2026-02-09
- **Decision:** The fog/vision system supports multiple perception modes that vary by character build, equipment, and ascension level. Each mode reveals different information with different trust/quality tradeoffs.
- **Confirmed modes:**
  - **Natural vision** - detail, color, identity. Blocked by walls. Everyone has it.
  - **Thermal** - heat signatures through walls. Body count but no identity. Higher biononic / military gear.
  - **Camera feeds** - remote visual from fixed positions. Only where cameras exist. Feed can be spoofed/looped. Hacker, institutional access, insert exploit.
  - **Unisphere tracking** - location pings of known individuals. Only active inserts, can be masked. Law enforcement / intelligence access.
  - **Audio analysis** - sound signatures, direction, classification. No visual. Insert processing, trainable skill.
- **Ascension scaling:**
  - Baseline: natural vision + carried gear
  - Enhanced: insert-based modes, camera access, audio processing
  - Higher: biononic thermal, enhanced spectrum, passive scanning
  - ANA-touched: pattern recognition across all feeds, predictive awareness
- **Playstyle implications (Nigel):** Low-tech Guardian playthrough = survival horror (blind, relying on contacts and paranoia). Senator playthrough = information overload (cameras and tracking but drowning in data). Perception modes are playstyle selectors.
- **v0.1:** Natural vision cone + basic audio indicators + insert minimap only. Additional modes are milestone features, each self-contained and modular.
- **Engine implication:** Each perception mode is an observer query against the information boundary system ([D-010](architecture.md#d-010-multiplayer-ready-architectural-baseline) principle 2). Engine doesn't distinguish between eyes/thermal/camera - all are "given this sensor, what state is visible?"
- **Raised by:** Team Leader (Jeroen) proposed thermal and camera hacking. Full team developed into perception mode framework.

### D-018: Three-range sound model
- **Date:** 2026-02-09
- **Decision:** Sound information reaches the player through three ranges with decreasing accuracy and trust:

| Range | Method | Info quality | Trust level |
|-------|--------|-------------|-------------|
| Close (near/in LOS) | Stereo audio (maps to facing direction with camera rotation) | High accuracy, identity possible | Raw sensory, reliable |
| Medium (outside LOS, nearby) | Visual indicators at fog edge + internal monologue | Directional, imprecise, type classification | Sensory impression, reliable but vague |
| Long (across map) | Insert notifications, text alerts | Specific but delayed, location data | Network-dependent, spoofable, manipulable |

- **Key insight:** Each range is a different information QUALITY, not just distance. Close = trustworthy. Long = potentially compromised. The Starflyer's agents would absolutely spoof long-range feeds.
- **v0.1:** Screen-space stereo for close + visual fog-edge indicators for medium. Long-range insert alerts as stretch goal.
- **Raised by:** Full team discussion.

### D-019: Top-down confirmed as primary camera, 3D cutscenes for key moments
- **Date:** 2026-02-09
- **Decision:** Top-down is the gameplay camera. Final. 3D cutscenes can be used for significant narrative moments (wormhole traversal, Dyson barrier opening, first contact, major reveals).
- **Rationale after full honest review:**
  - What first-person would give us (visceral traversal, face-to-face conversations, natural asymmetry, spatial horror) is real but compensated by: vision cone + fog, internal monologue, perception mode overlays, sound model
  - What top-down gives us that first-person can't: multi-layer information observation, tactical combat clarity, system legibility, NPC simulation visibility, strategic UI coexistence, 5-10x faster prototype
  - Key insight (Gestalt): the fun is systems interacting - observation → insert check → thermal → monologue → mental note → exploitation. That sequence is BETTER top-down.
  - Key insight (Paula): monologue interpreting faces/conversations is arguably richer than player reading 3D faces, and more faithful to Hamilton's close-POV writing style
  - 3D cutscenes recapture the visceral moments without burdening gameplay engineering. They're decoupled, can be added as polish, game ships complete without them.
  - Camera change to 3D IS the dramatic signal - player knows something significant is happening (Gestalt)
- **Architecture note (Tyre):** Client-server separation means the renderer is swappable. A full first-person client is architecturally possible in the future. Top-down now doesn't mean top-down forever.
- **v0.1:** Top-down only. No cutscenes. Those are milestone features.
- **Raised by:** Team Leader (Jeroen), after full team review of tradeoffs in Round 12.

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*6 decisions. Last updated: 2026-02-11*