fix(movement): jump works locally (airborne velocity preserved)

Two fixes for jump physics:
- Skip ground-snap when velocity Z > 0 (prevents immediate re-landing
  at high framerates where per-frame Z delta < 0.05 snap threshold)
- Guard apply_current_movement velocity write behind OnWalkable check
  (prevents MotionInterpreter.DoMotion from zeroing jump velocity on
  every frame while airborne)
- Guard PlayerMovementController velocity replacement behind OnWalkable
  (preserves momentum during airborne flight)

Jump works locally but server packet not yet sent (BUG-002).
Facing direction mismatch logged as BUG-003.
RunRate not verified as BUG-004.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/bugs.md

@@ -18,6 +18,37 @@ the "Fixed" section with the commit hash that resolved it.
   or the CreaturePalette pipeline in `InstancedMeshRenderer`.
 - **Phase:** Unassigned (investigate after rendering rebuild Step 5).
 
+### BUG-002: Jump not visible from retail client
+- **Observed:** 2026-04-14
+- **Description:** Jump works locally (player rises and falls) but no
+  jump packet is sent to the server. Other clients don't see the jump.
+- **Repro:** Jump in acdream, observe from retail client — no jump visible.
+- **Likely area:** GameWindow.cs jump packet sending (currently a TODO
+  Console.WriteLine). Need to research jump packet format from holtburger.
+- **Phase:** B.2 (movement completion)
+
+### BUG-003: Facing direction mismatch with server
+- **Observed:** 2026-04-14
+- **Description:** Character facing direction in acdream doesn't match
+  what other clients see. Our quaternion convention for outbound
+  MoveToState/AutonomousPosition packets is wrong.
+  AC convention: heading 0 = West, 90 = North, 180 = East, 270 = South.
+  Our convention: Yaw 0 = +X (East in AC terms). The wireRot quaternion
+  needs to use holtburger's `from_heading` formula:
+  `theta = (450 - degrees).to_radians()`, `w=cos(theta/2)`, `z=sin(theta/2)`.
+- **Repro:** Walk in acdream, observe from retail client — character faces
+  wrong direction.
+- **Likely area:** GameWindow.cs wireRot computation (line ~1899).
+- **Phase:** B.2 (movement completion)
+
+### BUG-004: Run speed not verified working
+- **Observed:** 2026-04-14
+- **Description:** RunRate wiring exists (Task 1) but user reported no
+  speed change. Either the server's UpdateMotion ForwardSpeed isn't being
+  received, or it's not propagating to the velocity computation. Need to
+  add diagnostic logging to verify the UpdateMotion path fires.
+- **Phase:** B.2 (movement completion)
+
 ---
 
 ## Fixed

docs/plans/2026-04-13-rendering-rebuild.md

@@ -1,9 +1,11 @@
-# Rendering Rebuild from ACME
+# Rendering Rebuild from ACME — COMPLETE
 
 Port ACME's rendering pipeline to acdream. Each step produces a
 visually testable result. The animation system stays unchanged (ACME
 has none — ours is ported from the decompiled client).
 
+**Status:** All 5 steps shipped 2026-04-13.
+
 ## Step 1: Port StaticObject shader + instanced rendering
 
 The biggest performance win. Replace per-entity DrawElements with

src/AcDream.App/Input/PlayerMovementController.cs

@@ -189,12 +189,6 @@ public sealed class PlayerMovementController
         _body.Orientation = Quaternion.CreateFromAxisAngle(Vector3.UnitZ, Yaw - MathF.PI / 2f);
 
         // ── 2. Set velocity via MotionInterpreter state machine ───────────────
-        // Snapshot the current vertical velocity BEFORE calling DoMotion.
-        // DoMotion routes through apply_current_movement → set_local_velocity,
-        // which overwrites _body.Velocity with the horizontal state speed and
-        // zeros Z.  We must snapshot Z first so we can restore it afterward.
-        float savedWorldVz = _body.Velocity.Z;
-
         // Determine the dominant forward/backward command and speed.
         uint forwardCmd;
         float forwardCmdSpeed;
@@ -205,7 +199,6 @@ public sealed class PlayerMovementController
         }
         else if (input.Backward)
         {
-            // WalkBackward is tracked in interpreted state; we negate Y velocity below.
             forwardCmd      = MotionCommand.WalkBackward;
             forwardCmdSpeed = 1.0f;
         }
@@ -215,7 +208,7 @@ public sealed class PlayerMovementController
             forwardCmdSpeed = 1.0f;
         }
 
-        // Update interpreted motion state.
+        // Update interpreted motion state (needed for animation + server messages).
         _motion.DoMotion(forwardCmd, forwardCmdSpeed);
 
         // Sidestep.
@@ -229,28 +222,30 @@ public sealed class PlayerMovementController
             _motion.StopInterpretedMotion(MotionCommand.SideStepLeft,  modifyInterpretedState: true);
         }
 
-        // get_state_velocity gives us the body-local speed magnitude from retail constants.
+        // Only replace velocity with motion interpreter output when grounded.
-        var stateVel = _motion.get_state_velocity();
+        // While airborne, the physics body's integrated velocity (from LeaveGround)
+        // persists — gravity pulls Z down, horizontal momentum is preserved.
+        // Retail AC works this way: you maintain momentum in the air.
+        if (_body.OnWalkable)
+        {
+            float savedWorldVz = _body.Velocity.Z;
+            var stateVel = _motion.get_state_velocity();
 
-        // Build the body-local velocity from the retail-derived speed values.
+            float localY = 0f;
-        // get_state_velocity only fills +X for SideStepRight and +Y for forward;
+            float localX = 0f;
-        // we must handle WalkBackward (negate Y) and SideStepLeft (negate X) manually.
-        float localY = 0f;
-        float localX = 0f;
 
-        if (input.Forward)
+            if (input.Forward)
-            localY =  stateVel.Y;                          // WalkAnimSpeed or RunAnimSpeed
+                localY =  stateVel.Y;
-        else if (input.Backward)
+            else if (input.Backward)
-            localY = -(MotionInterpreter.WalkAnimSpeed * 0.65f); // retail backward is ~65% walk
+                localY = -(MotionInterpreter.WalkAnimSpeed * 0.65f);
 
-        if (input.StrafeRight)
+            if (input.StrafeRight)
-            localX =  MotionInterpreter.SidestepAnimSpeed * 0.5f;
+                localX =  MotionInterpreter.SidestepAnimSpeed * 0.5f;
-        else if (input.StrafeLeft)
+            else if (input.StrafeLeft)
-            localX = -MotionInterpreter.SidestepAnimSpeed * 0.5f;
+                localX = -MotionInterpreter.SidestepAnimSpeed * 0.5f;
 
-        // Restore the vertical velocity snapshotted before DoMotion clobbered it.
+            _body.set_local_velocity(new Vector3(localX, localY, savedWorldVz));
-        // Rotation about Z does not affect the Z component, so world Vz == local Vz.
+        }
-        _body.set_local_velocity(new Vector3(localX, localY, savedWorldVz));
 
         // ── 3. Jump (charged) ─────────────────────────────────────────────────
         // Hold spacebar to charge (0→1 over JumpChargeRate seconds).
@@ -301,9 +296,9 @@ public sealed class PlayerMovementController
             float groundZ = resolveResult.Position.Z;
             float bodyZ   = _body.Position.Z;
 
-            if (bodyZ <= groundZ + 0.05f)
+            if (bodyZ <= groundZ + 0.05f && _body.Velocity.Z <= 0f)
             {
-                // Player is at or below the ground — snap to surface and land.
+                // Player is at or below the ground AND not jumping upward — snap to surface.
                 _body.Position = new Vector3(_body.Position.X, _body.Position.Y, groundZ);
 
                 bool wasAirborne = !_body.OnWalkable;

src/AcDream.Core/Physics/MotionInterpreter.cs

@@ -539,8 +539,17 @@ public sealed class MotionInterpreter
         if (InterpretedState.ForwardCommand == MotionCommand.RunForward)
             MyRunRate = InterpretedState.ForwardSpeed;
 
-        var localVelocity = get_state_velocity();
+        // Only replace velocity when grounded. While airborne, the physics
-        PhysicsObj.set_local_velocity(localVelocity);
+        // body's integrated velocity (from LeaveGround) should persist —
+        // gravity pulls Z down, horizontal momentum is preserved.
+        // The retail client's apply_current_movement also gates on Contact+OnWalkable
+        // before writing velocity (the full decompiled flow routes through
+        // update_object which checks transient state).
+        if (PhysicsObj.OnWalkable)
+        {
+            var localVelocity = get_state_velocity();
+            PhysicsObj.set_local_velocity(localVelocity);
+        }
     }
 
     // ── FUN_00529390 — jump ───────────────────────────────────────────────────