Changes

src/components/XRHud.tsx

@@ -2,7 +2,7 @@ import { useState } from 'react';
 import {
   Eye, LayoutGrid, Grid3X3, Box, Ruler, Trash2, Camera,
   Move, RotateCw, RefreshCw, ChevronUp, ChevronDown, Grip,
-  ClipboardCheck, X,
+  ClipboardCheck, X, Crosshair,
 } from 'lucide-react';
 import { Button } from '@/components/ui/button';
 import { Slider } from '@/components/ui/slider';
@@ -17,9 +17,11 @@ const ROTATION_STEP = 0.1;
 interface XRHudProps {
   freeMove: boolean;
   onToggleFreeMove: () => void;
+  placementMode?: boolean;
+  onTogglePlacement?: () => void;
 }
 
-export function XRHud({ freeMove, onToggleFreeMove }: XRHudProps) {
+export function XRHud({ freeMove, onToggleFreeMove, placementMode = false, onTogglePlacement }: XRHudProps) {
   const [expanded, setExpanded] = useState(false);
   const [checklistOpen, setChecklistOpen] = useState(false);
 
@@ -147,6 +149,18 @@ export function XRHud({ freeMove, onToggleFreeMove }: XRHudProps) {
                 {expanded ? <ChevronDown className="h-4 w-4" /> : <ChevronUp className="h-4 w-4" />}
               </Button>
 
+              {/* Hit-test placement toggle */}
+              {onTogglePlacement && (
+                <Button
+                  variant={placementMode ? 'default' : 'outline'}
+                  size="sm" className="h-8 gap-1.5 text-[10px] font-mono"
+                  onClick={onTogglePlacement}
+                >
+                  <Crosshair className="h-3.5 w-3.5" />
+                  {placementMode ? 'Posicionar…' : 'Reposicionar'}
+                </Button>
+              )}
+
               <Button
                 variant={freeMove ? 'default' : 'outline'}
                 size="sm" className="h-8 gap-1.5 text-[10px] font-mono"

src/components/three/XRHitTestPlacement.tsx

@@ -0,0 +1,133 @@
+import { useRef, useState, useCallback, useEffect } from 'react';
+import { useFrame } from '@react-three/fiber';
+import { useXRHitTest, useXRRequestHitTest } from '@react-three/xr';
+import * as THREE from 'three';
+
+const matrixHelper = new THREE.Matrix4();
+const positionHelper = new THREE.Vector3();
+const quaternionHelper = new THREE.Quaternion();
+
+interface XRHitTestPlacementProps {
+  placementMode: boolean;
+  onPlace: (position: THREE.Vector3, quaternion: THREE.Quaternion) => void;
+  children: React.ReactNode;
+}
+
+/**
+ * Uses @react-three/xr useXRHitTest to show a reticle on real-world surfaces.
+ * Tap (select) to place the model at the reticle position.
+ */
+export function XRHitTestPlacement({ placementMode, onPlace, children }: XRHitTestPlacementProps) {
+  const reticleRef = useRef<THREE.Mesh>(null);
+  const [reticlePos, setReticlePos] = useState<THREE.Vector3 | null>(null);
+  const [reticleQuat, setReticleQuat] = useState<THREE.Quaternion | null>(null);
+  const [placed, setPlaced] = useState(false);
+  const prevPlacementMode = useRef(placementMode);
+  const placedPosition = useRef(new THREE.Vector3(0, 0, -1.5));
+  const placedQuaternion = useRef(new THREE.Quaternion());
+
+  // Continuous hit-test from the viewer (camera center)
+  useXRHitTest(
+    placementMode && !placed
+      ? (results, getWorldMatrix) => {
+          if (results.length === 0) {
+            setReticlePos(null);
+            return;
+          }
+          getWorldMatrix(matrixHelper, results[0]);
+          positionHelper.setFromMatrixPosition(matrixHelper);
+          quaternionHelper.setFromRotationMatrix(matrixHelper);
+          setReticlePos(positionHelper.clone());
+          setReticleQuat(quaternionHelper.clone());
+        }
+      : undefined,
+    'viewer'
+  );
+
+  // Request-based hit test for tap-to-place
+  const requestHitTest = useXRRequestHitTest();
+
+  const handleSelect = useCallback(async () => {
+    if (!placementMode) return;
+
+    // Use current reticle position if available
+    if (reticlePos) {
+      placedPosition.current.copy(reticlePos);
+      if (reticleQuat) placedQuaternion.current.copy(reticleQuat);
+      setPlaced(true);
+      onPlace(reticlePos.clone(), reticleQuat?.clone() ?? new THREE.Quaternion());
+      console.log('[HitTest] 📍 Modelo posicionado via reticle:', reticlePos.toArray());
+      return;
+    }
+
+    // Fallback: on-demand hit test
+    if (!requestHitTest) return;
+    const result = await requestHitTest('viewer', ['plane', 'mesh']);
+    if (!result || result.results.length === 0) return;
+    result.getWorldMatrix(matrixHelper, result.results[0]);
+    const pos = new THREE.Vector3().setFromMatrixPosition(matrixHelper);
+    const quat = new THREE.Quaternion().setFromRotationMatrix(matrixHelper);
+    placedPosition.current.copy(pos);
+    placedQuaternion.current.copy(quat);
+    setPlaced(true);
+    onPlace(pos, quat);
+    console.log('[HitTest] 📍 Modelo posicionado via requestHitTest:', pos.toArray());
+  }, [placementMode, reticlePos, reticleQuat, onPlace, requestHitTest]);
+
+  // Update reticle mesh position each frame
+  useFrame(() => {
+    if (reticleRef.current) {
+      if (reticlePos && placementMode && !placed) {
+        reticleRef.current.visible = true;
+        reticleRef.current.position.copy(reticlePos);
+        if (reticleQuat) reticleRef.current.quaternion.copy(reticleQuat);
+      } else {
+        reticleRef.current.visible = false;
+      }
+    }
+  });
+
+  // Reset placement when user re-enters placement mode
+  useEffect(() => {
+    if (placementMode && !prevPlacementMode.current) {
+      setPlaced(false);
+    }
+    prevPlacementMode.current = placementMode;
+  }, [placementMode]);
+
+  return (
+    <>
+      {/* Reticle on detected surface */}
+      <mesh
+        ref={reticleRef}
+        visible={false}
+        onClick={handleSelect}
+        pointerEventsType={{ deny: 'grab' as any }}
+      >
+        <ringGeometry args={[0.08, 0.1, 32]} />
+        <meshBasicMaterial color="#22c55e" side={THREE.DoubleSide} transparent opacity={0.8} />
+      </mesh>
+
+      {/* Invisible tap plane to catch select events */}
+      {placementMode && !placed && (
+        <mesh
+          position={[0, 0, -2]}
+          onClick={handleSelect}
+          visible={false}
+          pointerEventsType={{ deny: 'grab' as any }}
+        >
+          <planeGeometry args={[10, 10]} />
+          <meshBasicMaterial transparent opacity={0} />
+        </mesh>
+      )}
+
+      {/* Placed model or default position */}
+      <group
+        position={placed ? placedPosition.current : [0, 0, -1.5]}
+        quaternion={placed ? placedQuaternion.current : undefined}
+      >
+        {children}
+      </group>
+    </>
+  );
+}

src/pages/XRSession.tsx

@@ -11,6 +11,7 @@ import { Button } from '@/components/ui/button';
 import { generateMarkerDownloadURL } from '@/lib/trackingMarker';
 import { XRHud } from '@/components/XRHud';
 import { findNearestVertex } from '@/components/three/SmartMeasure';
+import { XRHitTestPlacement } from '@/components/three/XRHitTestPlacement';
 
 // --- Diagnóstico XR ---
 console.log('[XR] Inicializando store...');
@@ -307,23 +308,15 @@ function XRGrid() {
   );
 }
 
-// ─── ImageTrackingAnchor ───────────────────────────────
-function ImageTrackingAnchor({ children }: { children: React.ReactNode }) {
-  const groupRef = useRef<THREE.Group>(null);
-  useFrame(() => {
-    if (!groupRef.current) return;
-    groupRef.current.position.set(0, 0, -1.5);
-    groupRef.current.quaternion.identity();
-  });
-  return <group ref={groupRef}>{children}</group>;
-}
+// ImageTrackingAnchor removed — replaced by XRHitTestPlacement
 
 // ─── XRSession Page ────────────────────────────────────
 const XRSession = () => {
   const navigate = useNavigate();
   const { model, anchorMode, setAnchorMode } = useModelStore();
   const [inXR, setInXR] = useState(false);
-  const [freeMove, setFreeMove] = useState(true); // default ON for easier positioning
+  const [freeMove, setFreeMove] = useState(true);
+  const [placementMode, setPlacementMode] = useState(true); // start in placement mode
 
   useEffect(() => {
     if (!model) navigate('/');
@@ -415,9 +408,15 @@ const XRSession = () => {
 
             <XROrigin />
 
-            <ImageTrackingAnchor>
+            <XRHitTestPlacement
+              placementMode={placementMode}
+              onPlace={() => {
+                setPlacementMode(false);
+                toast.success('Modelo posicionado na superfície!');
+              }}
+            >
               <XRModel url={model.url} />
-            </ImageTrackingAnchor>
+            </XRHitTestPlacement>
 
             <XRMeasurementOverlay />
             <XRSnapHandler />
@@ -427,7 +426,12 @@ const XRSession = () => {
         </Canvas>
 
         {/* Floating HUD overlay with all controls */}
-        <XRHud freeMove={freeMove} onToggleFreeMove={() => setFreeMove(!freeMove)} />
+        <XRHud
+          freeMove={freeMove}
+          onToggleFreeMove={() => setFreeMove(!freeMove)}
+          placementMode={placementMode}
+          onTogglePlacement={() => setPlacementMode(!placementMode)}
+        />
       </div>
     </div>
   );