From 57b72922690013aa045417e3d5736d79774526fa Mon Sep 17 00:00:00 2001
From: Your Name <your.email@example.com>
Date: Thu, 30 Apr 2026 17:38:13 +0800
Subject: [PATCH] fix: improve world viewer camera targeting

---
 components/canvas/world3d/World3DViewer.tsx | 25 +++++++++++++--------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/components/canvas/world3d/World3DViewer.tsx b/components/canvas/world3d/World3DViewer.tsx
index b78ae4408..1492bb5e0 100644
--- a/components/canvas/world3d/World3DViewer.tsx
+++ b/components/canvas/world3d/World3DViewer.tsx
@@ -286,11 +286,13 @@ function positionCameraInsideWorld({
   controls,
   splatMesh,
   groundPlaneOffset,
+  firstPerson = false,
 }: {
   camera: THREE.Camera;
   controls: { target?: THREE.Vector3; update?: () => void } | null;
   splatMesh: SparkSplatMesh;
   groundPlaneOffset: number | null;
+  firstPerson?: boolean;
 }): WorldCameraPose | null {
   if (!(camera instanceof THREE.PerspectiveCamera)) return null;
 
@@ -364,28 +366,30 @@ function positionCameraInsideWorld({
     lookDirection.copy(horizontalAxis).multiplyScalar(-1);
   }
   lookDirection.normalize();
-  const targetPosition = cameraPosition
+  const nearTargetPosition = cameraPosition
     .clone()
     .addScaledVector(lookDirection, THREE.MathUtils.clamp(majorSpan * 0.24, 0.75, 2.4));
-  targetPosition.y = THREE.MathUtils.clamp(
+  nearTargetPosition.y = THREE.MathUtils.clamp(
     eyeY - THREE.MathUtils.clamp(size.y * 0.025, 0.04, 0.18),
     minEyeY <= maxEyeY ? minEyeY : worldBounds.min.y,
     minEyeY <= maxEyeY ? maxEyeY : worldBounds.max.y
   );
-  targetPosition.x = clampInsideAxis(
-    targetPosition.x,
+  nearTargetPosition.x = clampInsideAxis(
+    nearTargetPosition.x,
     worldBounds.min.x,
     worldBounds.max.x,
     Math.max(size.x * 0.08, 0.18),
     center.x
   );
-  targetPosition.z = clampInsideAxis(
-    targetPosition.z,
+  nearTargetPosition.z = clampInsideAxis(
+    nearTargetPosition.z,
     worldBounds.min.z,
     worldBounds.max.z,
     Math.max(size.z * 0.08, 0.18),
     center.z
   );
+  const orbitTargetPosition = anchor.clone();
+  const targetPosition = firstPerson ? nearTargetPosition : orbitTargetPosition;
 
   camera.position.copy(cameraPosition);
   camera.lookAt(targetPosition);
@@ -879,6 +883,7 @@ function WorldSplatScene({
           lastCameraPoseRef.current = positionCameraInsideWorld({
             camera,
             controls: orbitControlsRef.current,
+            firstPerson,
             groundPlaneOffset,
             splatMesh,
           });
@@ -912,7 +917,7 @@ function WorldSplatScene({
       }
       splatMesh.dispose();
     };
-  }, [camera, groundPlaneOffset, onLoadStateChange, sparkRenderer, splatMesh]);
+  }, [camera, firstPerson, groundPlaneOffset, onLoadStateChange, sparkRenderer, splatMesh]);
 
   useEffect(() => {
     if (!hasAppliedInitialViewRef.current) return;
@@ -921,10 +926,11 @@ function WorldSplatScene({
     lastCameraPoseRef.current = positionCameraInsideWorld({
       camera,
       controls: orbitControlsRef.current,
+      firstPerson,
       groundPlaneOffset,
       splatMesh,
     });
-  }, [camera, groundPlaneOffset, resetViewToken, splatMesh]);
+  }, [camera, firstPerson, groundPlaneOffset, resetViewToken, splatMesh]);
 
   useEffect(() => {
     if (!hasAppliedInitialViewRef.current) {
@@ -932,10 +938,11 @@ function WorldSplatScene({
       return;
     }
 
-    if (!lastFirstPersonRef.current && firstPerson) {
+    if (lastFirstPersonRef.current !== firstPerson) {
       lastCameraPoseRef.current = positionCameraInsideWorld({
         camera,
         controls: orbitControlsRef.current,
+        firstPerson,
         groundPlaneOffset,
         splatMesh,
       });