Correction after the user (who has played retail and observed the camera pull in
at walls) flagged the prior "no camera collision" conclusion. Verified against the
decomp: retail's camera collision lives in SmartBox::update_viewer (0x00453ce0),
NOT CameraManager::UpdateCamera. The earlier research traced only the producer
(UpdateCamera computes the desired/damped eye -> viewer_sought_position) and missed
the consumer (update_viewer), which sweeps a 0.3 m viewer_sphere via
CTransition::find_valid_position from the head-pivot to that eye and uses the
stopped position (fallbacks: AdjustPosition, then snap to player). The player-fade
when super close (CameraSet::UpdateCamera -> SetTranslucencyHierarchical) is a
SEPARATE stage, already ported as RetailChaseCamera.ComputeTranslucency.
Implication: a swept-sphere camera collision is RETAIL-FAITHFUL, not a divergence —
no special sign-off needed, and acdream already owns the Transition swept-sphere
engine. Updated TL;DR, KEY FINDING, the fix section (was "design decision"),
slot-in (collide the damped eye, after RetailChaseCamera.cs:131), open questions,
pickup prompt, and reference index. Memory updated likewise.
Lesson recorded: when the decomp says "no X" but a domain expert says X exists,
trace the CONSUMER of the computed value, not just the producer.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Root cause of the A8.F flap / missing-walls reframed (with the user's help):
the 3rd-person camera EYE passes through walls, and the A8.F renderer keys its
"am I inside?" (PointInCell) and portal side-tests (CameraOnInteriorSide) off
that eye position (camPos = invView translation, GameWindow.cs:7271). Eye clips
a wall -> those decisions flip frame-to-frame -> the flap.
Key finding from camera research (Opus agent + verified against the decomp):
retail's camera does NOT collide with walls either — it fades the player to
translucent (CameraSet::UpdateCamera @ 0x00458ae0 -> SetTranslucencyHierarchical),
which acdream already ports as RetailChaseCamera.ComputeTranslucency. So a
"spring arm that pulls the eye in on a wall hit" is a deliberate divergence from
retail, not a faithful port — needs user sign-off before coding.
Handoff documents: the eye->visibility coupling + flap mechanism, acdream's
current camera (the ported turn/jump input-lag = damping + velocity ring +
mouse filter; no collision), retail's camera (symbols+addresses), the reusable
swept-sphere collision machinery (BSPQuery.FindCollisions vs CellPhysics.BSP),
3 fix options (lead: modern spring arm), open design questions, apparatus, and a
pickup prompt.
Bug A (cellar terrain flood) already fixed + committed in 9417d3c; the
recursive-clip builder works (the prior "Bug B" framing was wrong).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
