its functionning

.claude/launch.json

@@ -0,0 +1,11 @@
+{
+  "version": "0.0.1",
+  "configurations": [
+    {
+      "name": "dev",
+      "runtimeExecutable": "npm",
+      "runtimeArgs": ["run", "dev"],
+      "port": 5173
+    }
+  ]
+}

src/components/gameplay/pylon/PylonDownedPylon.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useRef, useState } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
 import { useFrame } from "@react-three/fiber";
 import { useGLTF } from "@react-three/drei";
 import * as THREE from "three";
@@ -33,13 +33,27 @@ export function PylonDownedPylon(): React.JSX.Element | null {
   }, [step]);
 
   const { scene } = useGLTF(PYLON_MODEL_PATH);
+  const clonedScene = useMemo(() => scene.clone(true), [scene]);
+
+  const showUpright =
+    mainState !== "pylon" ||
+    step === "waiting" ||
+    step === "inspected" ||
+    step === "fragmented" ||
+    step === "scanning" ||
+    step === "repairing" ||
+    step === "reassembling" ||
+    step === "done" ||
+    step === "narrator-outro";
 
   useFrame(() => {
     const group = groupRef.current;
     if (!group) return;
 
     if (!isStraightening || straightenStartRef.current === null) {
-      group.rotation.set(...(showUpright ? PYLON_UPRIGHT_ROTATION : PYLON_DOWNED_ROTATION));
+      group.rotation.set(
+        ...(showUpright ? PYLON_UPRIGHT_ROTATION : PYLON_DOWNED_ROTATION),
+      );
       return;
     }
 
@@ -55,19 +69,19 @@ export function PylonDownedPylon(): React.JSX.Element | null {
     );
   });
 
-  const showUpright =
-    mainState !== "pylon" ||
-    step === "waiting" ||
-    step === "inspected" ||
-    step === "fragmented" ||
-    step === "scanning" ||
-    step === "repairing" ||
-    step === "reassembling" ||
-    step === "done" ||
-    step === "narrator-outro";
-
   const isPylonInteractive = step === "arrived" || step === "npc-return";
 
+  // During these steps the RepairGame renders its own pylon model
+  // (exploded / reassembling / completion). Rendering the solid world
+  // pylon on top would double the heaviest model's GPU cost at the same
+  // spot — a prime cause of WebGL context loss. Let RepairGame own it.
+  const repairGameOwnsModel =
+    mainState === "pylon" &&
+    (step === "fragmented" ||
+      step === "scanning" ||
+      step === "reassembling" ||
+      step === "done");
+
   const beginStraighten = (): void => {
     setIsStraightening(true);
     pylonStraighteningSignal.started = true;
@@ -80,17 +94,19 @@ export function PylonDownedPylon(): React.JSX.Element | null {
       setIsStraightening(false);
       pylonStraighteningSignal.started = false;
       setCanMove(true);
-      setMissionStep("pylon", "inspected");
+      setMissionStep("pylon", "waiting");
     }, PYLON_STRAIGHTEN_ANIMATION_DURATION_MS);
   };
 
+  if (repairGameOwnsModel) return null;
+
   return (
     <group
       ref={groupRef}
       position={PYLON_WORLD_POSITION}
       rotation={PYLON_DOWNED_ROTATION}
     >
-      <primitive object={scene.clone(true)} />
+      <primitive object={clonedScene} />
       {isPylonInteractive ? (
         <InteractableObject
           kind="trigger"
@@ -117,7 +133,10 @@ export function PylonDownedPylon(): React.JSX.Element | null {
                       void (async () => {
                         const m = await loadDialogueManifest();
                         if (!m) return;
-                        await playDialogueById(m, PYLON_NARRATIVE_DIALOGUES.demandeAide);
+                        await playDialogueById(
+                          m,
+                          PYLON_NARRATIVE_DIALOGUES.demandeAide,
+                        );
                       })();
                     },
                     { once: true },
@@ -127,7 +146,10 @@ export function PylonDownedPylon(): React.JSX.Element | null {
                 void (async () => {
                   const manifest = await loadDialogueManifest();
                   if (!manifest) return;
-                  await playDialogueById(manifest, PYLON_NARRATIVE_DIALOGUES.demandeAide);
+                  await playDialogueById(
+                    manifest,
+                    PYLON_NARRATIVE_DIALOGUES.demandeAide,
+                  );
                 })();
               }
             } else if (step === "npc-return" && !isStraightening) {

src/components/gameplay/pylon/PylonNarrativeFlow.tsx

@@ -1,3 +1,4 @@
+import { useEffect } from "react";
 import { useGameStore } from "@/managers/stores/useGameStore";
 import { useDialoguePlayback } from "@/hooks/gameplay/useDialoguePlayback";
 import { ZoneDetection } from "@/components/zone/ZoneDetection";
@@ -28,6 +29,16 @@ export function PylonNarrativeFlow(): React.JSX.Element | null {
     onComplete: () => completeMission("pylon"),
   });
 
+  // Advance waiting → inspected in a separate macrotask so React and Rapier
+  // finish their current commit before RigidBody colliders are created.
+  useEffect(() => {
+    if (mainState !== "pylon" || step !== "waiting") return undefined;
+    const id = window.setTimeout(() => {
+      setMissionStep("pylon", "inspected");
+    }, 0);
+    return () => window.clearTimeout(id);
+  }, [mainState, step, setMissionStep]);
+
   if (mainState !== "pylon") return null;
 
   if (step === "locked") {

src/components/three/gameplay/RepairCaseModel.tsx

@@ -219,7 +219,11 @@ export function RepairCaseModel({
       parsedScale[2] * pop.current.scale,
     );
 
-    if (placeholderNodes.current.length > 0) {
+    // Placeholders are only consumed when the case is open (repairing). While
+    // floating (inspected/scanning) the case bobs every frame, so emitting here
+    // would fire a React setState on every frame, re-rendering the whole
+    // RepairGame subtree continuously. Only compute when not floating.
+    if (!floating && placeholderNodes.current.length > 0) {
       const placeholders: RepairCasePlaceholder[] = [];
       placeholderNodes.current.forEach((child) => {
         child.getWorldPosition(placeholderPosition.current);

src/components/three/gameplay/RepairGame.tsx

@@ -2,7 +2,6 @@ import { Suspense, useEffect, useMemo, useState } from "react";
 import { useGLTF } from "@react-three/drei";
 import { ExplodableModel } from "@/components/three/models/ExplodableModel";
 import type { RepairCasePlaceholder } from "@/components/three/gameplay/RepairCaseModel";
-import { RepairCompletionStep } from "@/components/three/gameplay/RepairCompletionStep";
 import { RepairInspectionObject } from "@/components/three/gameplay/RepairInspectionObject";
 import { RepairMissionCase } from "@/components/three/gameplay/RepairMissionCase";
 import { RepairRepairingStep } from "@/components/three/gameplay/RepairRepairingStep";
@@ -10,7 +9,9 @@ import { RepairReassemblyStep } from "@/components/three/gameplay/RepairReassemb
 import { RepairScanSequence } from "@/components/three/gameplay/RepairScanSequence";
 import { REPAIR_CASE_MODEL_PATH } from "@/data/gameplay/repairCaseConfig";
 import { REPAIR_FRAGMENTATION_SEQUENCE_SECONDS } from "@/data/gameplay/repairGameConfig";
+import { getNextMissionStep } from "@/data/gameplay/repairMissionState";
 import { REPAIR_MISSIONS } from "@/data/gameplay/repairMissions";
+import { useRepairTransitionStore } from "@/managers/stores/useRepairTransitionStore";
 import { useRepairFragmentationInput } from "@/hooks/gameplay/useRepairFragmentationInput";
 import { useRepairMissionStep } from "@/hooks/gameplay/useRepairMissionStep";
 import { useTerrainSnappedPosition } from "@/hooks/three/useTerrainHeight";
@@ -30,6 +31,8 @@ interface RepairGameProps extends Required<
   mission: RepairMissionId;
   rotation?: Vector3Tuple;
   scale?: ModelTransformProps["scale"];
+  /** Set to false in isolated scenes with no terrain (e.g. RepairGameScene). */
+  snapToTerrain?: boolean;
 }
 
 interface RepairMissionAssetPreloaderProps {
@@ -54,6 +57,7 @@ export function RepairGame({
   position,
   rotation = [0, 0, 0],
   scale = 1,
+  snapToTerrain = true,
 }: RepairGameProps): React.JSX.Element | null {
   const config = REPAIR_MISSIONS[mission];
   const mainState = useGameStore((state) => state.mainState);
@@ -67,7 +71,11 @@ export function RepairGame({
     readonly RepairScannedBrokenPart[]
   >([]);
   const parsedScale = toVector3Scale(scale);
-  const snappedPosition = useTerrainSnappedPosition(position);
+  // useTerrainSnappedPosition must always be called (rules of hooks) but we
+  // only use its result when snapToTerrain is true — in the isolated repair
+  // scene there is no terrain, so we use the raw position directly.
+  const snappedByTerrain = useTerrainSnappedPosition(position);
+  const snappedPosition = snapToTerrain ? snappedByTerrain : position;
   const readyForFragmentation = step === "inspected";
 
   useRepairFragmentationInput({
@@ -103,6 +111,24 @@ export function RepairGame({
     };
   }, [mainState, mission, setMissionStep, step]);
 
+  // When "done" is reached: set pendingCompletion in the transition store.
+  // useRepairGameStatus detects this and triggers the fade back to world.
+  // page.tsx waits for the world to fully load, THEN executes the completion.
+  // This ensures the player sees a loading screen rather than a black flash.
+  useEffect(() => {
+    if (mainState !== mission || step !== "done") return undefined;
+
+    const timeoutId = window.setTimeout(() => {
+      const nextStep = getNextMissionStep("done", mission);
+      useRepairTransitionStore.getState().setPendingCompletion({
+        mission,
+        nextStep,
+      });
+    }, 200);
+
+    return () => window.clearTimeout(timeoutId);
+  }, [mainState, mission, step]);
+
   if (mainState !== mission) return null;
   if (step === "locked") return null;
 
@@ -149,12 +175,9 @@ export function RepairGame({
             onComplete={() => setMissionStep(mission, "done")}
           />
         ) : null}
-        {step === "done" ? (
-          <RepairCompletionStep
-            config={config}
-            onComplete={() => completeMission(mission)}
-          />
-        ) : null}
+        {/* done step: auto-advance is handled by useEffect above — no manual
+            case-closing interaction needed. Scene is intentionally empty
+            for the 200ms before completeMission/setMissionStep fires. */}
         {step !== "waiting" && step !== "done" && step !== "reassembling" ? (
           <RepairMissionCase
             config={config}

src/components/three/gameplay/RepairGamePreloader.tsx

@@ -0,0 +1,37 @@
+import { useEffect } from "react";
+import { useGLTF } from "@react-three/drei";
+import { REPAIR_CASE_MODEL_PATH } from "@/data/gameplay/repairCaseConfig";
+import { REPAIR_MISSIONS } from "@/data/gameplay/repairMissions";
+import type { RepairMissionId } from "@/types/gameplay/repairMission";
+
+function getPreloadPaths(mission: RepairMissionId): string[] {
+  const config = REPAIR_MISSIONS[mission];
+  return [
+    ...new Set([
+      REPAIR_CASE_MODEL_PATH,
+      config.modelPath,
+      ...config.brokenParts.flatMap((p) => p.modelPath ?? []),
+      ...config.replacementParts.flatMap((p) => p.modelPath ?? []),
+    ]),
+  ];
+}
+
+interface RepairGamePreloaderProps {
+  mission: RepairMissionId;
+}
+
+/**
+ * Fires useGLTF.preload() for every asset used by a repair mission.
+ * Renders nothing — pure background loading.
+ */
+export function RepairGamePreloader({
+  mission,
+}: RepairGamePreloaderProps): null {
+  useEffect(() => {
+    for (const path of getPreloadPaths(mission)) {
+      useGLTF.preload(path);
+    }
+  }, [mission]);
+
+  return null;
+}

src/components/three/gameplay/RepairScanSequence.tsx

@@ -41,16 +41,16 @@ export function RepairScanSequence({
   useEffect(() => {
     if (parts.length === 0) return undefined;
 
+    // Do NOT call onComplete inside a setState updater — updaters run during
+    // React's render phase, which would trigger a setState on RepairGame and
+    // cause a "setState during render" error. Call it directly in the timeout.
     const timeoutId = window.setTimeout(() => {
-      setActivePartIndex((currentIndex) => {
-        const nextIndex = currentIndex + 1;
-        if (nextIndex >= parts.length) {
-          onComplete(getScannedBrokenParts(parts, config));
-          return currentIndex;
-        }
-
-        return nextIndex;
-      });
+      const nextIndex = activePartIndex + 1;
+      if (nextIndex >= parts.length) {
+        onComplete(getScannedBrokenParts(parts, config));
+      } else {
+        setActivePartIndex(nextIndex);
+      }
     }, scanPartSeconds * 1000);
 
     return () => {

src/hooks/gameplay/useRepairGameStatus.ts

@@ -0,0 +1,43 @@
+import { useGameStore } from "@/managers/stores/useGameStore";
+import { useRepairTransitionStore } from "@/managers/stores/useRepairTransitionStore";
+import { isRepairGameStep } from "@/types/gameplay/repairMission";
+import type { RepairMissionId } from "@/types/gameplay/repairMission";
+
+export interface RepairGameStatus {
+  active: boolean;
+  mission: RepairMissionId | null;
+}
+
+/**
+ * Returns whether a repair game is currently active and for which mission.
+ * Drives the scene swap in page.tsx: when active, the heavy 3D world is
+ * unmounted and a lightweight isolated repair scene is shown instead.
+ */
+export function useRepairGameStatus(): RepairGameStatus {
+  const mainState = useGameStore((state) => state.mainState);
+  const ebikeStep = useGameStore((state) => state.ebike.currentStep);
+  const pylonStep = useGameStore((state) => state.pylon.currentStep);
+  const farmStep = useGameStore((state) => state.farm.currentStep);
+  // When pendingCompletion is set the repair game is "done" but we want the
+  // world to finish loading before executing the completion. Returning
+  // active=false here triggers the fade back to the world scene.
+  const pendingCompletion = useRepairTransitionStore(
+    (s) => s.pendingCompletion,
+  );
+
+  if (pendingCompletion !== null) {
+    return { active: false, mission: null };
+  }
+
+  if (mainState === "ebike" && isRepairGameStep(ebikeStep)) {
+    return { active: true, mission: "ebike" };
+  }
+  if (mainState === "pylon" && isRepairGameStep(pylonStep)) {
+    return { active: true, mission: "pylon" };
+  }
+  if (mainState === "farm" && isRepairGameStep(farmStep)) {
+    return { active: true, mission: "farm" };
+  }
+
+  return { active: false, mission: null };
+}

src/managers/stores/useRepairTransitionStore.ts

@@ -0,0 +1,33 @@
+import { create } from "zustand";
+import type { MissionStep, RepairMissionId } from "@/types/gameplay/repairMission";
+import type { Vector3Tuple } from "@/types/three/three";
+
+export interface RepairPendingCompletion {
+  mission: RepairMissionId;
+  /** Next step to set. When it equals "done", completeMission() is called
+   *  instead (ebike / farm have no further narrative sub-step). */
+  nextStep: MissionStep;
+}
+
+interface RepairTransitionState {
+  /** Set when the repair game reaches "done". page.tsx reads this and
+   *  executes the completion only after the world has fully re-loaded. */
+  pendingCompletion: RepairPendingCompletion | null;
+  /** Player 3D position captured just before entering the repair scene,
+   *  used to re-spawn the player at the correct location on return. */
+  savedPlayerPosition: Vector3Tuple | null;
+}
+
+interface RepairTransitionActions {
+  setPendingCompletion: (data: RepairPendingCompletion | null) => void;
+  setSavedPlayerPosition: (pos: Vector3Tuple | null) => void;
+}
+
+export const useRepairTransitionStore = create<
+  RepairTransitionState & RepairTransitionActions
+>()((set) => ({
+  pendingCompletion: null,
+  savedPlayerPosition: null,
+  setPendingCompletion: (data) => set({ pendingCompletion: data }),
+  setSavedPlayerPosition: (pos) => set({ savedPlayerPosition: pos }),
+}));

src/managers/stores/useWorldSettingsStore.ts

@@ -1,4 +1,5 @@
 import { create } from "zustand";
+import { persist } from "zustand/middleware";
 import { CLOUD_DEFAULTS, type CloudState } from "@/data/world/cloudConfig";
 import { FOG_CONFIG, type FogState } from "@/data/world/fogConfig";
 import { WIND_DEFAULTS, type WindState } from "@/data/world/windConfig";
@@ -46,7 +47,9 @@ const DEFAULT_STATE: WorldSettingsState = {
   graphics: { ...GRAPHICS_DEFAULTS },
 };
 
-export const useWorldSettingsStore = create<WorldSettingsStore>()((set) => ({
+export const useWorldSettingsStore = create<WorldSettingsStore>()(
+  persist(
+    (set) => ({
   ...DEFAULT_STATE,
 
   setClouds: (cloudsUpdate) =>
@@ -115,4 +118,12 @@ export const useWorldSettingsStore = create<WorldSettingsStore>()((set) => ({
     })),
 
   resetToDefaults: () => set(DEFAULT_STATE),
-}));
+    }),
+    {
+      name: "la-fabrik-world-settings",
+      // Persist only graphics settings (preset + options) — fog/wind/clouds
+      // reset to defaults on each session.
+      partialize: (state) => ({ graphics: state.graphics }),
+    },
+  ),
+);

src/pages/page.tsx

@@ -15,25 +15,28 @@ import {
 } from "@/components/ui/intro";
 import { SceneLoadingOverlay } from "@/components/ui/SceneLoadingOverlay";
 import { INITIAL_SCENE_LOADING_STATE } from "@/data/world/sceneLoadingConfig";
+import { useRepairGameStatus } from "@/hooks/gameplay/useRepairGameStatus";
 import { useTransientLoadingIndicator } from "@/hooks/ui/useTransientLoadingIndicator";
 import { AudioManager } from "@/managers/AudioManager";
 import { useGameStore } from "@/managers/stores/useGameStore";
+import { useRepairTransitionStore } from "@/managers/stores/useRepairTransitionStore";
 import { useWorldSettingsStore } from "@/managers/stores/useWorldSettingsStore";
 import { HandTrackingProvider } from "@/providers/gameplay/HandTrackingProvider";
+import type { RepairMissionId } from "@/types/gameplay/repairMission";
 import type { SceneLoadingState } from "@/types/world/sceneLoading";
 import { hasSiteBeenVisitedToday } from "@/utils/cookies/siteVisitCookie";
 import { logger } from "@/utils/core/Logger";
+import { RepairGameScene } from "@/world/RepairGameScene";
 import { World } from "@/world/World";
 
 const LOADING_TO_VIDEO_FADE_MS = 500;
+// Duration (ms) of each half of the repair scene cross-fade
+const REPAIR_FADE_MS = 250;
 
 export function HomePage(): React.JSX.Element | null {
   const navigate = useNavigate();
   const mainState = useGameStore((state) => state.mainState);
   const introStep = useGameStore((state) => state.intro.currentStep);
-  const ebikeStep = useGameStore((state) => state.ebike.currentStep);
-  const pylonStep = useGameStore((state) => state.pylon.currentStep);
-  const farmStep = useGameStore((state) => state.farm.currentStep);
   const setIntroStep = useGameStore((state) => state.setIntroStep);
   const graphicsPreset = useWorldSettingsStore(
     (state) => state.graphics.preset,
@@ -48,9 +51,92 @@ export function HomePage(): React.JSX.Element | null {
     INITIAL_SCENE_LOADING_STATE,
   );
   const sceneReadyRef = useRef(false);
-  const runtimeLoadingSignal = `${graphicsPreset}:${mainState}:${ebikeStep}:${pylonStep}:${farmStep}`;
+  // Only trigger the transient loading indicator on mission-level transitions
+  // (mainState) or graphics changes — not on every repair game sub-step.
+  const runtimeLoadingSignal = `${graphicsPreset}:${mainState}`;
   const previousRuntimeLoadingSignalRef = useRef(runtimeLoadingSignal);
 
+  // --- Repair scene swap ---------------------------------------------------
+  const repairStatus = useRepairGameStatus();
+  const pendingCompletion = useRepairTransitionStore(
+    (s) => s.pendingCompletion,
+  );
+  const setPendingCompletion = useRepairTransitionStore(
+    (s) => s.setPendingCompletion,
+  );
+  const setSavedPlayerPosition = useRepairTransitionStore(
+    (s) => s.setSavedPlayerPosition,
+  );
+
+  const [showRepairScene, setShowRepairScene] = useState(repairStatus.active);
+  const [renderedMission, setRenderedMission] =
+    useState<RepairMissionId | null>(
+      repairStatus.active ? repairStatus.mission : null,
+    );
+  const [isFading, setIsFading] = useState(false);
+  // True while the world is reloading after a repair scene (shows loading overlay).
+  const [isPostRepairLoading, setIsPostRepairLoading] = useState(false);
+  const lastRepairActiveRef = useRef(repairStatus.active);
+
+  useEffect(() => {
+    if (repairStatus.active === lastRepairActiveRef.current) return;
+    lastRepairActiveRef.current = repairStatus.active;
+
+    if (repairStatus.active) {
+      // Entering repair scene — capture the player's current world position
+      // so we can restore it when returning.
+      const pos = (window as Window & { playerPos?: [number, number, number] })
+        .playerPos;
+      if (pos) setSavedPlayerPosition([pos[0], pos[1], pos[2]]);
+    }
+
+    setIsFading(true);
+
+    const swapTimer = window.setTimeout(() => {
+      setShowRepairScene(repairStatus.active);
+      setRenderedMission(repairStatus.active ? repairStatus.mission : null);
+
+      if (!repairStatus.active) {
+        // Returning from repair scene — reset loading state so the overlay
+        // shows while the world reloads from scratch (new WebGL context).
+        sceneReadyRef.current = false;
+        setSceneLoadingState(INITIAL_SCENE_LOADING_STATE);
+        setIsPostRepairLoading(true);
+      }
+
+      window.setTimeout(() => {
+        setIsFading(false);
+      }, 50);
+    }, REPAIR_FADE_MS);
+
+    return () => window.clearTimeout(swapTimer);
+  }, [repairStatus.active, repairStatus.mission, setSavedPlayerPosition]);
+
+  // Execute the pending repair completion once the world is fully loaded.
+  useEffect(() => {
+    if (!isPostRepairLoading) return;
+    if (sceneLoadingState.status !== "ready") return;
+    if (!pendingCompletion) return;
+
+    const { mission, nextStep } = pendingCompletion;
+    const store = useGameStore.getState();
+
+    if (nextStep === "done") {
+      store.completeMission(mission);
+    } else {
+      store.setMissionStep(mission, nextStep);
+    }
+
+    setPendingCompletion(null);
+    setIsPostRepairLoading(false);
+  }, [
+    isPostRepairLoading,
+    sceneLoadingState.status,
+    pendingCompletion,
+    setPendingCompletion,
+  ]);
+  // -------------------------------------------------------------------------
+
   useEffect(() => {
     sceneReadyRef.current = sceneLoadingState.status === "ready";
   }, [sceneLoadingState.status]);
@@ -168,7 +254,9 @@ export function HomePage(): React.JSX.Element | null {
     introStep === "fade-to-video" ||
     (introStep === "loading-map" && sceneLoadingState.status === "ready");
   const showSceneLoadingOverlay =
-    introStep === "loading-map" || introStep === "fade-to-video";
+    introStep === "loading-map" ||
+    introStep === "fade-to-video" ||
+    isPostRepairLoading;
 
   const renderIntroOverlay = () => {
     if (showFadeToVideoOverlay) return <FadeToVideoOverlay />;
@@ -187,21 +275,46 @@ export function HomePage(): React.JSX.Element | null {
 
   return (
     <HandTrackingProvider>
-      <Canvas
-        camera={{ position: [85, 60, 85], fov: 42 }}
-        shadows={{ type: THREE.PCFShadowMap }}
-        gl={{
-          powerPreference: "high-performance",
-          antialias: true,
-          stencil: false,
+      {showRepairScene && renderedMission !== null ? (
+        /* Isolated repair scene — no map, no player, no physics world.
+           Unmounting the main Canvas here frees the full GPU budget. */
+        <RepairGameScene mission={renderedMission} />
+      ) : (
+        <Canvas
+          camera={{ position: [85, 60, 85], fov: 42 }}
+          shadows={{ type: THREE.PCFShadowMap }}
+          gl={{
+            powerPreference: "high-performance",
+            antialias: true,
+            stencil: false,
+          }}
+          onCreated={handleCanvasCreated}
+        >
+          <Suspense fallback={null}>
+            <World onLoadingStateChange={handleSceneLoadingStateChange} />
+            <DebugPerf />
+          </Suspense>
+        </Canvas>
+      )}
+
+      {/* Black fade overlay — covers the WebGL context swap.
+          The AppLoadingIndicator lives INSIDE this div so it inherits the
+          stacking context (z-index 60) and always paints above the black. */}
+      <div
+        aria-hidden="true"
+        style={{
+          position: "fixed",
+          inset: 0,
+          background: "#000",
+          zIndex: 60,
+          opacity: isFading ? 1 : 0,
+          transition: `opacity ${REPAIR_FADE_MS}ms ease-in-out`,
+          pointerEvents: isFading ? "all" : "none",
         }}
-        onCreated={handleCanvasCreated}
       >
-        <Suspense fallback={null}>
-          <World onLoadingStateChange={handleSceneLoadingStateChange} />
-          <DebugPerf />
-        </Suspense>
-      </Canvas>
+        {isFading ? <AppLoadingIndicator floating /> : null}
+      </div>
+
       <GameUI />
       {dialogMessage ? (
         <DialogMessage

src/world/GameStageContent.tsx

@@ -1,22 +1,18 @@
 import { Ebike } from "@/components/ebike/Ebike";
 import { InteractableObject } from "@/components/three/interaction/InteractableObject";
-import { RepairGame } from "@/components/three/gameplay/RepairGame";
+import { RepairGamePreloader } from "@/components/three/gameplay/RepairGamePreloader";
 import { PylonDownedPylon } from "@/components/gameplay/pylon/PylonDownedPylon";
 import { PylonNarrativeFlow } from "@/components/gameplay/pylon/PylonNarrativeFlow";
 import { ZoneDebugVisual } from "@/components/zone/ZoneDetection";
 import { PYLON_APPROACH_ZONE, PYLON_ARRIVED_ZONE } from "@/data/gameplay/zones";
 import { isDebugEnabled } from "@/utils/debug/isDebugEnabled";
-import {
-  REPAIR_MISSION_POSITION_ENTRIES,
-  REPAIR_MISSION_TRIGGERS,
-} from "@/data/gameplay/repairMissionAnchors";
+import { REPAIR_MISSION_TRIGGERS } from "@/data/gameplay/repairMissionAnchors";
 import {
   INTRO_STAGE_ANCHOR,
   OUTRO_STAGE_ANCHOR,
 } from "@/data/gameplay/gameStageAnchors";
 import { useGameStore } from "@/managers/stores/useGameStore";
 import { useRepairMissionAnchorStore } from "@/managers/stores/useRepairMissionAnchorStore";
-import { isPylonNarrativeStep } from "@/types/gameplay/repairMission";
 import type { RepairMissionTriggerConfig } from "@/types/gameplay/repairMission";
 import type { Vector3Tuple } from "@/types/three/three";
 import { getRepairMissionPosition } from "@/utils/gameplay/repairMissionPosition";
@@ -83,14 +79,18 @@ function RepairMissionTrigger({
 
 export function GameStageContent(): React.JSX.Element {
   const mainState = useGameStore((state) => state.mainState);
-  const pylonStep = useGameStore((state) => state.pylon.currentStep);
-  const anchors = useRepairMissionAnchorStore((state) => state.anchors);
-
-  const pylonInNarrative =
-    mainState === "pylon" && isPylonNarrativeStep(pylonStep);
 
   return (
     <>
+      {/* Pre-load the next mission's repair assets while the player is still
+          in the world, so the isolated repair scene mounts instantly.
+          Only load pylon during ebike (not before) to avoid holding a
+          finished mission's textures in VRAM. */}
+      {mainState === "intro" || mainState === "ebike" ? (
+        <RepairGamePreloader mission="pylon" />
+      ) : null}
+      {mainState === "pylon" ? <RepairGamePreloader mission="farm" /> : null}
+
       {mainState === "intro" ? <StageAnchor {...INTRO_STAGE_ANCHOR} /> : null}
       <Ebike position={EBIKE_WORLD_POSITION} />
       <PylonDownedPylon />
@@ -101,14 +101,13 @@ export function GameStageContent(): React.JSX.Element {
         </>
       ) : null}
       {mainState === "pylon" ? <PylonNarrativeFlow /> : null}
-      {REPAIR_MISSION_POSITION_ENTRIES.map(({ mission }) => {
-        const position = getRepairMissionPosition(mission, anchors);
-        if (!position) return null;
-        if (mission === "pylon" && pylonInNarrative) return null;
-        return (
-          <RepairGame key={mission} mission={mission} position={position} />
-        );
-      })}
+
+      {/* RepairGame is NO LONGER rendered here. When a repair step becomes
+          active, page.tsx unmounts this whole world and mounts the isolated
+          RepairGameScene instead, freeing all map/character VRAM. */}
+
+      {/* Trigger sphere that starts the ebike repair (locked → waiting).
+          The repair scene swap is then handled by useRepairGameStatus. */}
       {REPAIR_MISSION_TRIGGERS.map((config) => (
         <RepairMissionTrigger key={config.mission} config={config} />
       ))}

src/world/RepairGameScene.tsx

@@ -0,0 +1,108 @@
+import { Suspense, useCallback, useEffect } from "react";
+import { Canvas, useThree } from "@react-three/fiber";
+import { Physics } from "@react-three/rapier";
+import * as THREE from "three";
+import { DebugPerf } from "@/components/debug/DebugPerf";
+import { RepairGame } from "@/components/three/gameplay/RepairGame";
+import { logger } from "@/utils/core/Logger";
+import type { RepairMissionId } from "@/types/gameplay/repairMission";
+import type { Vector3Tuple } from "@/types/three/three";
+
+// Isolated scene — no world offset, no terrain. The repair game runs
+// fully centred in its own context so the heavy map never loads here.
+const REPAIR_SCENE_POSITION: Vector3Tuple = [0, 0, 0];
+
+// Background: very dark blue-grey to match Altera's night-time mood
+const REPAIR_SCENE_BG = "#0b0d14";
+
+// Lighting tuned to match the main world defaults from lightingConfig.ts
+const AMBIENT_COLOR = "#dfe7d8";
+const AMBIENT_INTENSITY = 0.9;
+const SUN_COLOR = "#ffe2bf";
+const SUN_INTENSITY = 2.2;
+const SUN_POSITION: Vector3Tuple = [5, 8, 4];
+
+// Mimic the first-person view from the main world:
+//   - PLAYER_EYE_HEIGHT = 1.75  → camera Y
+//   - Case floats at [0, 0.4, 1.8] (inspected) → [0, 1.05, 2.05] (repairing)
+//   - Look-at target averaged between those two states
+const CAMERA_POSITION: Vector3Tuple = [5, 2, 2];
+const CAMERA_LOOK_AT: Vector3Tuple = [0, 0.7, 1.9];
+
+function RepairSceneCamera(): null {
+  const { camera } = useThree();
+
+  useEffect(() => {
+    camera.lookAt(...CAMERA_LOOK_AT);
+  }, [camera]);
+
+  return null;
+}
+
+interface RepairGameSceneProps {
+  mission: RepairMissionId;
+}
+
+export function RepairGameScene({
+  mission,
+}: RepairGameSceneProps): React.JSX.Element {
+  const handleCreated = useCallback(({ gl }: { gl: THREE.WebGLRenderer }) => {
+    const canvas = gl.domElement;
+    const loseContextExt = gl.getContext().getExtension("WEBGL_lose_context");
+
+    const handleContextLost = (event: Event) => {
+      event.preventDefault();
+      logger.error("WebGL", "Repair scene context lost — attempting restore");
+      window.setTimeout(() => loseContextExt?.restoreContext(), 500);
+    };
+
+    const handleContextRestored = () => {
+      logger.info("WebGL", "Repair scene context restored");
+    };
+
+    canvas.addEventListener("webglcontextlost", handleContextLost);
+    canvas.addEventListener("webglcontextrestored", handleContextRestored);
+  }, []);
+
+  return (
+    <Canvas
+      camera={{ position: CAMERA_POSITION, fov: 42 }}
+      shadows={{ type: THREE.PCFShadowMap }}
+      gl={{
+        powerPreference: "high-performance",
+        antialias: true,
+        stencil: false,
+      }}
+      onCreated={handleCreated}
+    >
+      <color attach="background" args={[REPAIR_SCENE_BG]} />
+
+      <RepairSceneCamera />
+
+      {/* Lighting — mirrors the game world defaults */}
+      <ambientLight intensity={AMBIENT_INTENSITY} color={AMBIENT_COLOR} />
+      <directionalLight
+        position={SUN_POSITION}
+        intensity={SUN_INTENSITY}
+        color={SUN_COLOR}
+        castShadow
+        shadow-mapSize-width={1024}
+        shadow-mapSize-height={1024}
+      />
+
+      <Suspense fallback={null}>
+        {/* Physics is required: TriggerObject and GrabbableObject both use
+            RigidBody. The world is minimal — no octree, no character bodies. */}
+        <Physics>
+          <RepairGame
+            mission={mission}
+            position={REPAIR_SCENE_POSITION}
+            snapToTerrain={false}
+          />
+        </Physics>
+      </Suspense>
+
+      <DebugPerf />
+    </Canvas>
+  );
+}

src/world/World.tsx

@@ -1,9 +1,10 @@
-import { Suspense, useEffect } from "react";
+import { Suspense, useEffect, useRef } from "react";
 import { Physics } from "@react-three/rapier";
 import {
   PLAYER_SPAWN_POSITION_GAME,
   PLAYER_SPAWN_POSITION_PHYSICS,
 } from "@/data/player/playerConfig";
+import { useRepairTransitionStore } from "@/managers/stores/useRepairTransitionStore";
 import { useCameraMode } from "@/hooks/debug/useCameraMode";
 import { useEnvironmentDebug } from "@/hooks/debug/useEnvironmentDebug";
 import { useMapPerformanceDebug } from "@/hooks/debug/useMapPerformanceDebug";
@@ -53,10 +54,31 @@ export function World({ onLoadingStateChange }: WorldProps): React.JSX.Element {
     handleShadowWarmupStarted,
     shouldWarmUpShadows,
   } = useWorldSceneLoading({ sceneMode, onLoadingStateChange });
-  const playerSpawnPosition =
-    sceneMode === "game"
-      ? PLAYER_SPAWN_POSITION_GAME
-      : PLAYER_SPAWN_POSITION_PHYSICS;
+  // Capture the spawn position once on mount via a ref so it never changes
+  // mid-session (spawnPosition is reactive in Player and would re-spawn the
+  // character on every prop change). If the player returns from a repair
+  // scene, savedPlayerPosition holds their world position; otherwise fall
+  // back to the default spawn from playerConfig.
+  const savedPlayerPosition = useRepairTransitionStore(
+    (s) => s.savedPlayerPosition,
+  );
+  const playerSpawnPositionRef = useRef(
+    savedPlayerPosition ??
+      (sceneMode === "game"
+        ? PLAYER_SPAWN_POSITION_GAME
+        : PLAYER_SPAWN_POSITION_PHYSICS),
+  );
+  const playerSpawnPosition = playerSpawnPositionRef.current;
+
+  // Clear the saved position right after capturing it so the next world
+  // mount uses the default spawn instead of the stale repair-exit position.
+  useEffect(() => {
+    if (savedPlayerPosition !== null) {
+      useRepairTransitionStore.getState().setSavedPlayerPosition(null);
+    }
+    // Only on mount — intentionally no deps
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
   const showHandTrackingGloves =
     sceneMode === "physics" ||
     (status !== "idle" && usageStatus !== "inactive");