From 099cad998de525da1438119793b32da3dfb02a07 Mon Sep 17 00:00:00 2001 From: arcattack Date: Thu, 9 Jul 2026 16:34:56 -0500 Subject: [PATCH] KB: incline shadow-vanish co-resolved with gait v5 (user-confirmed live) The shadow report was a desync symptom, not a bias/tilt bug: the ~2-4 unit depth-bias margin is tight enough that v4's out-of-phase leg pose showing through could push the flat quad under a slope. No shadow code changed; both symptoms cleared together. Noted as a diagnostic hint (check [sync]/BT_SYNC_LOG before touching bias/tilt for this report class). Co-Authored-By: Claude Fable 5 --- context/locomotion.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/context/locomotion.md b/context/locomotion.md index 1ec55fa..21dff2b 100644 --- a/context/locomotion.md +++ b/context/locomotion.md @@ -91,6 +91,11 @@ BT 4.10's shadow is the flat `*_tshd.bgf` proxy drawn as blend-pass geometry, po a depth-bias (`D3DRS_DEPTHBIAS`, decal-style) stops it z-fighting/vanishing on inclines. Polar maps have STUB `*_tshd` (shadow authored-off on snow). Also the visual-ground conform (`btvisgnd.cpp`, render-only lift to the visible terrain triangles — presentation only, never touches localOrigin). [T2] +⚠ **"Shadow vanishes on inclines" can be a GAIT-DESYNC symptom, not a bias/tilt bug.** The 2026-07-09 +recurrence CO-RESOLVED with the gait v5 fix (user-confirmed live; no shadow code changed). The bias +margin is only ~2-4 world units, so anything that pops the displayed root pose (v4's out-of-phase leg +channel showing through) can push the flat quad under the slope → vanish [T2 observation; mechanism +T4]. Before touching bias/tilt for this report, check `[sync]`/`BT_SYNC_LOG` for channel drift first. ## Key Relationships - Detail: `docs/P3_LOCOMOTION.md`. Uses: [[asset-formats]] (SKL/ANI), [[decomp-reference]] (offsets).