diff --git a/src/components/ViewerControls.tsx b/src/components/ViewerControls.tsx
index 25a5682..1fdff3b 100644
--- a/src/components/ViewerControls.tsx
+++ b/src/components/ViewerControls.tsx
@@ -1,4 +1,4 @@
-import { Eye, Grid3X3, Ruler, Trash2, Camera, LayoutGrid, Palette, Box, Move3D, Undo2, MousePointerClick, EyeOff, Focus, Download, Square, Scissors } from 'lucide-react';
+import { Eye, Grid3X3, Ruler, Trash2, Camera, LayoutGrid, Palette, Box, Move3D, Undo2, MousePointerClick, EyeOff, Focus, Download, Square, Scissors, Footprints } from 'lucide-react';
 import { Slider } from '@/components/ui/slider';
 import { Button } from '@/components/ui/button';
 import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
@@ -31,6 +31,7 @@ export function ViewerControls() {
     wireframeThickness, setWireframeThickness,
     edgeThresholdAngle, setEdgeThresholdAngle,
     positionMode, setPositionMode,
+    walkMode, setWalkMode,
     activeModelId, models,
     selectionMode, setSelectionMode,
     selectedElementKeys, hiddenElementKeys, isolatedElementKeys,
@@ -268,6 +269,25 @@ export function ViewerControls() {
         </span>
       </Button>
 
+      {/* Walk mode */}
+      <Button
+        variant={walkMode ? 'default' : 'outline'}
+        size="sm"
+        className="gap-2 h-9"
+        onClick={() => {
+          if (!walkMode) {
+            toast.info("Modo Caminhada: Use WASD para se mover e o mouse para olhar ao redor. Pressione ESC para sair.");
+          }
+          setWalkMode(!walkMode);
+        }}
+        title="Modo primeira pessoa (WASD para andar)"
+      >
+        <Footprints className="h-3.5 w-3.5" />
+        <span className="font-mono text-xs">
+          Caminhar
+        </span>
+      </Button>
+
       {/* Measure tool */}
       <div className="flex items-end gap-1.5">
         <Button
diff --git a/src/components/three/ModelViewer.tsx b/src/components/three/ModelViewer.tsx
index e7a8314..b22fe2a 100644
--- a/src/components/three/ModelViewer.tsx
+++ b/src/components/three/ModelViewer.tsx
@@ -1,6 +1,6 @@
 import { Suspense, useRef, useMemo, useEffect, type ReactNode, useState } from 'react';
 import { Canvas, useThree, useFrame } from '@react-three/fiber';
-import { OrbitControls, useGLTF, Grid, Html, Line, PerspectiveCamera, OrthographicCamera } from '@react-three/drei';
+import { OrbitControls, useGLTF, Grid, Html, Line, PerspectiveCamera, OrthographicCamera, PointerLockControls, Sky, Environment } from '@react-three/drei';
 import { Loader2 } from 'lucide-react';
 import * as THREE from 'three';
 import { useModelStore, type SceneModel } from '@/stores/useModelStore';
@@ -1330,10 +1330,124 @@ function PositionDragHandler() {
 
 
 
+function WalkControls() {
+  const walkMode = useModelStore(s => s.walkMode);
+  const setWalkMode = useModelStore(s => s.setWalkMode);
+  const gridY = useModelStore(s => s.gridY);
+  const { camera } = useThree();
+  const controlsRef = useRef<any>(null);
+  const keys = useRef({ w: false, a: false, s: false, d: false, shift: false });
+  const initialized = useRef(false);
+
+  useEffect(() => {
+    if (walkMode && !initialized.current) {
+      camera.position.set(0, gridY + 1.7, 5);
+      // Give the camera an initial rotation looking forward
+      camera.rotation.set(0, 0, 0);
+      initialized.current = true;
+    } else if (!walkMode) {
+      initialized.current = false;
+    }
+  }, [walkMode, camera, gridY]);
+
+  useEffect(() => {
+    if (walkMode) {
+      // Small timeout to allow canvas to render and be clickable
+      const timer = setTimeout(() => {
+        try { controlsRef.current?.lock(); } catch (e) {}
+      }, 100);
+      return () => clearTimeout(timer);
+    }
+  }, [walkMode]);
+
+  useEffect(() => {
+    const onKeyDown = (e: KeyboardEvent) => {
+      if (e.code === 'KeyW') keys.current.w = true;
+      if (e.code === 'KeyA') keys.current.a = true;
+      if (e.code === 'KeyS') keys.current.s = true;
+      if (e.code === 'KeyD') keys.current.d = true;
+      if (e.code === 'ShiftLeft' || e.code === 'ShiftRight') keys.current.shift = true;
+    };
+    const onKeyUp = (e: KeyboardEvent) => {
+      if (e.code === 'KeyW') keys.current.w = false;
+      if (e.code === 'KeyA') keys.current.a = false;
+      if (e.code === 'KeyS') keys.current.s = false;
+      if (e.code === 'KeyD') keys.current.d = false;
+      if (e.code === 'ShiftLeft' || e.code === 'ShiftRight') keys.current.shift = false;
+    };
+    window.addEventListener('keydown', onKeyDown);
+    window.addEventListener('keyup', onKeyUp);
+    return () => {
+      window.removeEventListener('keydown', onKeyDown);
+      window.removeEventListener('keyup', onKeyUp);
+    };
+  }, []);
+
+  useFrame((_, dt) => {
+    if (!walkMode) return;
+    const speed = keys.current.shift ? 6.0 : 2.5;
+    const dir = new THREE.Vector3();
+    
+    // Front vector (ignoring pitch to walk purely horizontally)
+    const front = new THREE.Vector3(0, 0, -1).applyQuaternion(camera.quaternion);
+    front.y = 0; 
+    if (front.lengthSq() > 0.001) front.normalize();
+
+    // Right vector
+    const right = new THREE.Vector3(1, 0, 0).applyQuaternion(camera.quaternion);
+    right.y = 0; 
+    if (right.lengthSq() > 0.001) right.normalize();
+
+    if (keys.current.w) dir.add(front);
+    if (keys.current.s) dir.sub(front);
+    if (keys.current.a) dir.sub(right);
+    if (keys.current.d) dir.add(right);
+
+    if (dir.lengthSq() > 0) {
+      dir.normalize();
+      camera.position.addScaledVector(dir, speed * dt);
+    }
+    // Always stick to exactly 1.7m above ground
+    camera.position.y = gridY + 1.7;
+  });
+
+  if (!walkMode) return null;
+
+  return (
+    <PointerLockControls 
+      ref={controlsRef} 
+      onUnlock={() => {
+        setWalkMode(false);
+      }}
+    />
+  );
+}
+
+function WalkEnvironment() {
+  const walkMode = useModelStore(s => s.walkMode);
+  const gridY = useModelStore(s => s.gridY);
+  if (!walkMode) return null;
+
+  return (
+    <group>
+      {/* Realistic blue sky with some clouds/haze */}
+      <Sky sunPosition={[100, 20, 100]} turbidity={0.1} rayleigh={0.5} mieCoefficient={0.005} mieDirectionalG={0.8} />
+      {/* Background HDRI provides distant trees, mountains, houses on the horizon */}
+      <Environment preset="park" background />
+      {/* Infinite walkable grass floor */}
+      <mesh rotation={[-Math.PI / 2, 0, 0]} position={[0, gridY - 0.01, 0]} receiveShadow>
+        <planeGeometry args={[1000, 1000]} />
+        <meshStandardMaterial color="#4ade80" roughness={0.9} metalness={0.1} />
+      </mesh>
+    </group>
+  );
+}
+
 export function ModelViewerCanvas({ url }: ModelViewerProps) {
   const positionMode = useModelStore((s) => s.positionMode);
   const measureMode = useModelStore((s) => s.measureMode);
   const selectionMode = useModelStore((s) => s.selectionMode);
+  const walkMode = useModelStore((s) => s.walkMode);
   return (
     <Canvas
       camera={{ position: [2, 2, 2], fov: 50, near: 0.001, far: 1000 }}
@@ -1376,6 +1490,9 @@ export function ModelViewerCanvas({ url }: ModelViewerProps) {
       <VisibilityApplier />
       <SceneRefCapture />
       <ViewCubeAnimator />
+      
+      <WalkControls />
+      <WalkEnvironment />
 
       <OrbitControls
         makeDefault
@@ -1385,7 +1502,7 @@ export function ModelViewerCanvas({ url }: ModelViewerProps) {
         maxDistance={50}
         minZoom={5}
         maxZoom={5000}
-        enabled={!positionMode}
+        enabled={!positionMode && !walkMode}
         ref={(c: any) => {
           mainControlsRef.current = c;
         }}
diff --git a/src/stores/useModelStore.ts b/src/stores/useModelStore.ts
index 37d1bf3..bb873c1 100644
--- a/src/stores/useModelStore.ts
+++ b/src/stores/useModelStore.ts
@@ -298,6 +298,8 @@ interface ModelStore {
   setMeasureMode: (on: boolean) => void;
   positionMode: boolean;
   setPositionMode: (on: boolean) => void;
+  walkMode: boolean;
+  setWalkMode: (on: boolean) => void;
 
   // ── Selection (hide/isolate/export elements) ────────────
   selectionMode: boolean;
@@ -605,9 +607,14 @@ export const useModelStore = create<ModelStore>((set, get) => ({
   resetChecklist: () => set({ checklist: defaultChecklist.map(i => ({ ...i })) }),
 
   measureMode: false,
-  setMeasureMode: (measureMode) => set((s) => ({ measureMode, measurePoints: [], positionMode: measureMode ? false : s.positionMode, selectionMode: measureMode ? false : s.selectionMode })),
+  setMeasureMode: (measureMode) => set((s) => ({ measureMode, measurePoints: [], positionMode: measureMode ? false : s.positionMode, selectionMode: measureMode ? false : s.selectionMode, walkMode: false })),
   positionMode: false,
-  setPositionMode: (positionMode) => set((s) => ({ positionMode, measureMode: positionMode ? false : s.measureMode, selectionMode: positionMode ? false : s.selectionMode })),
+  setPositionMode: (positionMode) => set((s) => ({ positionMode, measureMode: positionMode ? false : s.measureMode, selectionMode: positionMode ? false : s.selectionMode, walkMode: false })),
+  walkMode: false,
+  setWalkMode: (walkMode) => {
+    set({ walkMode });
+    if (walkMode) set({ positionMode: false, measureMode: false, selectionMode: false, cameraMode: 'persp' });
+  },
 
   // ── Selection state ─────────────────────────────────────
   selectionMode: false,