diff --git a/src/app/TileBasemap.cpp b/src/app/TileBasemap.cpp
index 6101ddc..cda36fb 100644
--- a/src/app/TileBasemap.cpp
+++ b/src/app/TileBasemap.cpp
@@ -8,6 +8,7 @@
 #include <QDebug>
 #include <QImage>
 #include <QNetworkReply>
+#include <QTimer>
 #include <QNetworkRequest>
 #include <QString>
 #include <QUrl>
@@ -107,7 +108,11 @@ long long TileBasemap::tileKey(int z, int x, int y) {
 
 TileBasemap::TileBasemap(geopro::render::Scene& scene, vtkRenderWindow* rw,
                          std::shared_ptr<geopro::core::GeoLocalFrame> frame, QObject* parent)
-    : QObject(parent), scene_(scene), rw_(rw), frame_(std::move(frame)) {}
+    : QObject(parent), scene_(scene), rw_(rw), frame_(std::move(frame)) {
+    refreshTimer_ = new QTimer(this);
+    refreshTimer_->setSingleShot(true);
+    connect(refreshTimer_, &QTimer::timeout, this, [this]() { refresh(); });
+}
 
 TileBasemap::~TileBasemap() {
     if (styleObs_ && observer_) styleObs_->RemoveObserver(observer_);
@@ -128,7 +133,8 @@ void TileBasemap::ensureObserver() {
 }
 
 void TileBasemap::onInteractionEnd(vtkObject*, unsigned long, void* clientData, void*) {
-    if (auto* self = static_cast<TileBasemap*>(clientData)) self->refresh();
+    // 防抖：交互(滚轮/旋转/平移)停止 ~140ms 后才刷新四叉树，避免每格事件都重算卡顿。
+    if (auto* self = static_cast<TileBasemap*>(clientData)) self->refreshTimer_->start(140);
 }
 
 void TileBasemap::enqueueGet(const QString& url, std::function<void(QNetworkReply*)> onDone) {
@@ -348,18 +354,19 @@ void TileBasemap::placeActor(long long key, vtkSmartPointer<vtkActor> actor) {
     placed_[key] = actor;
 }
 
-void TileBasemap::ensureBaseline(const QImage& dem) {
-    if (haveBaseline_) return;  // 仅首块定基准 → base/detail 共用同一基准，地形连续无断层
-    baseline_ = demElev(dem, 0.5, 0.5);
+void TileBasemap::ensureBaseline(int z, int x, int y, const QImage& dem) {
+    if (haveBaseline_) return;
+    // 基准必须锚"数据中心"的地面高程(确定性)：只有含数据中心的块来定，按中心点采样。
+    // 否则四叉树里随便哪块先到都定基准 → 地形整体偏移 → 三维剖面相对地面忽上忽下。
+    const auto c = frame_->toLatLon(0.0, 0.0);  // 数据中心经纬
+    const geopro::render::TileXY ct = geopro::render::lonLatToTile(c.lon, c.lat, z);
+    if (ct.x != x || ct.y != y) return;  // 此块不含数据中心 → 不用它定基准
+    const geopro::render::LonLatBox b = geopro::render::tileBounds(z, x, y);
+    const double fx = (c.lon - b.west) / (b.east - b.west);   // 数据中心在块内的列比例
+    const double fy = (b.north - c.lat) / (b.north - b.south);  // 行比例(顶=北)
+    baseline_ = demElev(dem, fx, fy);
     haveBaseline_ = true;
-    double mn = 1e30, mx = -1e30;
-    for (int yy = 0; yy < dem.height(); yy += 16)
-        for (int xx = 0; xx < dem.width(); xx += 16) {
-            const double e = demElev(dem, xx / double(dem.width() - 1), yy / double(dem.height() - 1));
-            mn = std::min(mn, e);
-            mx = std::max(mx, e);
-        }
-    qInfo() << "[basemap] 地形启用 baseline=" << baseline_ << "m 起伏=" << (mx - mn) << "m";
+    qInfo() << "[basemap] 地形启用 baseline(数据中心)=" << baseline_ << "m z=" << z;
 }
 
 vtkSmartPointer<vtkActor> TileBasemap::buildFlat(int z, int x, int y,
@@ -396,7 +403,7 @@ void TileBasemap::fetchTerrain(int z, int x, int y, long long key, vtkSmartPoint
     // 落地一块瓦片：DEM 有效→起伏，否则→平面兜底；并推进 inFlight/清理。
     auto place = [this, key, z, x, y, dz, dx, dy, tex](const QImage* dem) {
         if (dem && !dem->isNull()) {
-            ensureBaseline(*dem);  // 首块定基准(base/detail 共用)→ 地形连续
+            ensureBaseline(dz, dx, dy, *dem);  // 用含数据中心的 DEM 块定基准(确定性)
             placeActor(key, buildWarped(z, x, y, dz, dx, dy, tex, *dem));
         } else {
             placeActor(key, buildFlat(z, x, y, tex));  // DEM 拉不到 → 平面兜底
diff --git a/src/app/TileBasemap.hpp b/src/app/TileBasemap.hpp
index 971c534..349b478 100644
--- a/src/app/TileBasemap.hpp
+++ b/src/app/TileBasemap.hpp
@@ -20,6 +20,7 @@ class vtkRenderWindow;
 class vtkInteractorObserver;
 class vtkCallbackCommand;
 class QNetworkReply;
+class QTimer;
 namespace geopro::render { class Scene; }
 namespace geopro::core { class GeoLocalFrame; }
 
@@ -49,7 +50,7 @@ private:
     void fetchTerrain(int z, int x, int y, long long key,
                       vtkSmartPointer<vtkTexture> tex);  // 拉覆盖该瓦片的 DEM(z>15 取祖先块)后落地
     void placeActor(long long key, vtkSmartPointer<vtkActor> actor);
-    void ensureBaseline(const QImage& dem);  // 首块 DEM 定基准高程(各层级共用→地形连续)
+    void ensureBaseline(int z, int x, int y, const QImage& dem);  // 用含数据中心的块定基准(确定性)
     vtkSmartPointer<vtkActor> buildFlat(int z, int x, int y,
                                         vtkSmartPointer<vtkTexture> tex);  // 平面瓦片(DEM 兜底)
     vtkSmartPointer<vtkActor> buildWarped(int sz, int sx, int sy, int dz, int dx, int dy,
@@ -84,6 +85,7 @@ private:
     bool terrainProbed_ = false;                           // 首次 fetchTerrain 打一行诊断日志
     vtkSmartPointer<vtkInteractorObserver> styleObs_;       // 持引用保证回调期有效
     vtkSmartPointer<vtkCallbackCommand> observer_;
+    QTimer* refreshTimer_ = nullptr;  // 交互防抖：滚轮/旋转停止后才刷新四叉树(避免每格卡)
     bool refreshing_ = false;
 };
 
diff --git a/src/app/VtkSceneView.cpp b/src/app/VtkSceneView.cpp
index 248ed28..5893001 100644
--- a/src/app/VtkSceneView.cpp
+++ b/src/app/VtkSceneView.cpp
@@ -182,7 +182,11 @@ void VtkSceneView::setAxes(geopro::controller::AxesMode mode, geopro::controller
 }
 
 void VtkSceneView::applyCameraView(geopro::controller::ViewDir dir) {
-    geopro::render::applyView(scene_.renderer(), toRenderViewDir(dir));
+    geopro::render::applyView(scene_.renderer(), toRenderViewDir(dir));  // 设朝向(内部 ResetCamera 含底图)
+    double bounds[6];
+    if (computeDataBounds(bounds))
+        scene_.renderer()->ResetCamera(bounds);  // 重新取景到数据(否则被~公里级底图推到超远)
+    scene_.renderer()->ResetCameraClippingRange();  // 裁剪面含底图
     if (renderWindow_) renderWindow_->Render();
 }