diff --git a/src/render/CMakeLists.txt b/src/render/CMakeLists.txt
index 89d7543..57523e3 100644
--- a/src/render/CMakeLists.txt
+++ b/src/render/CMakeLists.txt
@@ -5,7 +5,7 @@ add_library(geopro_render STATIC
   interact/SlicePlaneMath.cpp interact/SliceTool.cpp interact/PickInteractorStyle.cpp interact/InteractionManager.cpp interact/AnomalyDrawTool.cpp
   ground/TileMath.cpp
   lod/ViewAdaptiveLodPolicy.cpp
-  source/WholeVolumeSource.cpp source/BrickPager.cpp source/OutOfCoreSource.cpp source/ViewAdaptiveVolumeSource.cpp)
+  source/WholeVolumeSource.cpp source/BrickPager.cpp source/OutOfCoreSource.cpp source/ViewAdaptiveVolumeSource.cpp source/RegionReorganizer.cpp source/AsyncRegionBuilder.cpp)
 target_include_directories(geopro_render PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(geopro_render PUBLIC geopro_core geopro_store ${VTK_LIBRARIES} GDAL::GDAL)
 target_compile_features(geopro_render PUBLIC cxx_std_17)
diff --git a/src/render/source/AsyncRegionBuilder.cpp b/src/render/source/AsyncRegionBuilder.cpp
new file mode 100644
index 0000000..2efc2f6
--- /dev/null
+++ b/src/render/source/AsyncRegionBuilder.cpp
@@ -0,0 +1,86 @@
+#include "source/AsyncRegionBuilder.hpp"
+
+#include <utility>
+
+namespace geopro::render {
+
+AsyncRegionBuilder::AsyncRegionBuilder(const std::string& storeDir)
+    : store_(storeDir) {
+  worker_ = std::thread([this] { workerLoop(); });
+}
+
+AsyncRegionBuilder::~AsyncRegionBuilder() {
+  {
+    std::lock_guard<std::mutex> lk(mutex_);
+    stop_.store(true);
+  }
+  cv_.notify_all();
+  if (worker_.joinable()) worker_.join();
+}
+
+void AsyncRegionBuilder::setMaxTextureDim(int dim) {
+  std::lock_guard<std::mutex> lk(mutex_);
+  if (dim > 0) maxTextureDim_ = dim;
+}
+
+void AsyncRegionBuilder::requestTarget(const RegionTarget& t) {
+  {
+    std::lock_guard<std::mutex> lk(mutex_);
+    // 与已就绪结果对应的目标相同则不必重建（避免重复劳动）；与在建/排队的期望相同
+    // 亦无需扰动。简化：直接覆盖期望并标脏——worker 会以最新期望为准（supersede）。
+    desired_ = t;
+    hasDesired_ = true;
+  }
+  cv_.notify_one();
+}
+
+vtkSmartPointer<vtkImageData> AsyncRegionBuilder::takeLatest() {
+  // 非阻塞：仅在锁内做指针移动（不做任何重组/IO/长时操作）。
+  // std::move 把 ready_ 的引用移交给返回值（无 refcount 增减，且全程在锁内/单线程），
+  // ready_ 置空——下次无新结果再调返回 nullptr。
+  std::lock_guard<std::mutex> lk(mutex_);
+  return std::move(ready_);
+}
+
+void AsyncRegionBuilder::workerLoop() {
+  std::unique_lock<std::mutex> lk(mutex_);
+  for (;;) {
+    // 等到有期望或停止。
+    cv_.wait(lk, [this] { return stop_.load() || hasDesired_; });
+    if (stop_.load()) return;
+
+    // 取出最新期望（supersede：只建当前最新，丢弃中途旧请求）。
+    const RegionTarget target = desired_;
+    const int maxDim = maxTextureDim_;
+    hasDesired_ = false;
+    building_ = true;
+
+    // 解锁后构建：worker 在自己线程内重组，主线程全程不触碰该局部 image。
+    lk.unlock();
+    vtkSmartPointer<vtkImageData> built =
+        reorganizeRegion(store_, target, maxDim);
+    lk.lock();
+
+    if (stop_.load()) return;
+
+    // 若构建期间又来了更新的期望，则本次结果已过期——丢弃，继续建最新。
+    // built 离开作用域前在锁内释放 refcount（单线程独占）。
+    if (hasDesired_) {
+      building_ = false;
+      built = nullptr;  // 锁内释放（单线程独占 refcount）
+      continue;
+    }
+
+    // publish：在锁内把所有权 move 进 ready_（旧 ready_ 若未取走在此处锁内释放）。
+    // 所有 refcount 增减均在锁内/单线程独占完成。
+    ready_ = std::move(built);
+    building_ = false;
+  }
+}
+
+bool AsyncRegionBuilder::hasPending() const {
+  std::lock_guard<std::mutex> lk(mutex_);
+  return hasDesired_ || building_;
+}
+
+}  // namespace geopro::render
diff --git a/src/render/source/AsyncRegionBuilder.hpp b/src/render/source/AsyncRegionBuilder.hpp
new file mode 100644
index 0000000..5800afc
--- /dev/null
+++ b/src/render/source/AsyncRegionBuilder.hpp
@@ -0,0 +1,72 @@
+#pragma once
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <string>
+#include <thread>
+
+#include <vtkImageData.h>
+#include <vtkSmartPointer.h>
+
+#include "data/store/ChunkedVolumeStore.hpp"
+#include "source/RegionReorganizer.hpp"
+
+namespace geopro::render {
+
+// C3 并发核心：把「从 store 重组视野区域单纹理」放后台线程，主线程非阻塞取最新
+// 就绪结果——使拖动/缩放时不被解压+重组卡住。
+//
+// 线程安全设计（VTK 引用计数跨线程要小心）：
+//   - 后台 worker 在自己线程内调 reorganizeRegion（C2/C3 共用重组核）构建出一个
+//     vtkSmartPointer<vtkImageData>（全程不被主线程触碰）。
+//   - 完成后在 mutex 下把它移交到成员 ready_。主线程在同一 mutex 下取走（移动出）。
+//     所有 vtkImageData 引用计数的增减都发生在锁内/单线程独占——避免两线程同时碰
+//     同一对象的 refcount。worker 构建期间主线程看不到它；publish 后所有权经锁交给
+//     主线程。
+//   - 请求合并/取最新（supersede）：worker 在建 A 时若 requestTarget(B)，完成 A 后
+//     去建最新期望（B），不堆积旧请求——主线程高频 update 不致排队爆炸。
+class AsyncRegionBuilder {
+ public:
+  // 起 worker 线程。storeDir：含金字塔的分块 store。
+  explicit AsyncRegionBuilder(const std::string& storeDir);
+
+  // 停 worker（join）。析构忙时干净 join 不崩、不泄漏、不死锁。
+  ~AsyncRegionBuilder();
+
+  AsyncRegionBuilder(const AsyncRegionBuilder&) = delete;
+  AsyncRegionBuilder& operator=(const AsyncRegionBuilder&) = delete;
+
+  // 主线程调：设期望目标。与当前在建/已建不同则唤醒 worker 重建；相同则忽略。
+  void requestTarget(const RegionTarget& t);
+
+  // 主线程调：取最新已就绪 image（非阻塞）。无新结果返回 nullptr（主线程继续用
+  // 上一张）。取走后清空，下次无新结果再调返回 nullptr。
+  // 永不阻塞主线程：仅在锁内做指针移动。
+  vtkSmartPointer<vtkImageData> takeLatest();
+
+  // 是否有在建/排队（供 UI/测试）。
+  bool hasPending() const;
+
+  // 单张 3D 纹理各轴上限（GL_MAX_3D_TEXTURE_SIZE）。须在 requestTarget 前设。
+  void setMaxTextureDim(int dim);
+
+ private:
+  void workerLoop();
+
+  geopro::data::ChunkedVolumeStore store_;
+
+  mutable std::mutex mutex_;
+  std::condition_variable cv_;
+
+  // 受 mutex_ 保护的共享状态：
+  RegionTarget desired_{};        // 主线程最新期望目标
+  bool hasDesired_ = false;       // 是否有未消费的期望
+  bool building_ = false;         // worker 当前是否在建
+  vtkSmartPointer<vtkImageData> ready_;  // 已就绪、待主线程取走的最新结果
+  std::atomic<bool> stop_{false};        // 析构置位，唤醒 worker 退出
+  int maxTextureDim_ = 16384;
+
+  std::thread worker_;  // 最后声明：构造完上述成员后再起线程
+};
+
+}  // namespace geopro::render
diff --git a/src/render/source/RegionReorganizer.cpp b/src/render/source/RegionReorganizer.cpp
new file mode 100644
index 0000000..953ca8c
--- /dev/null
+++ b/src/render/source/RegionReorganizer.cpp
@@ -0,0 +1,119 @@
+#include "source/RegionReorganizer.hpp"
+
+#include <algorithm>
+#include <cstdint>
+#include <vector>
+
+#include <vtkNew.h>
+#include <vtkPointData.h>
+#include <vtkShortArray.h>
+
+namespace geopro::render {
+
+namespace {
+
+// 该 level 某轴体素维度 = ceil(n / 2^level)，至少 1（与 C1/store 同口径）。
+int dimAtLevel(int n, int level) {
+  const int d = (n + (1 << level) - 1) >> level;
+  return d > 0 ? d : 1;
+}
+
+}  // namespace
+
+vtkSmartPointer<vtkImageData> reorganizeRegion(
+    const geopro::data::ChunkedVolumeStore& store, const RegionTarget& target,
+    int maxTextureDim) {
+  const geopro::data::StoreMeta& meta = store.meta();
+  const int level = target.level;
+  const double exagg = target.exagg > 0 ? target.exagg : 1.0;
+
+  const int brick = meta.brick;
+  const int dimLx = dimAtLevel(meta.nx, level);
+  const int dimLy = dimAtLevel(meta.ny, level);
+  const int dimLz = dimAtLevel(meta.nz, level);
+
+  // 重组单纹理某轴范围（与 C1 hpp 契约逐字一致）：
+  //   起点 = b0*brick；终点 = min(b1*brick, dimL, 起点 + maxTextureDim)。
+  // 即使 brick > maxTextureDim（单块超限），也按体素上限再裁 → 恒 ≤ maxTextureDim。
+  const int gi0 = target.bx0 * brick;
+  const int gj0 = target.by0 * brick;
+  const int gk0 = target.bz0 * brick;
+  const int gi1 = std::min({target.bx1 * brick, dimLx, gi0 + maxTextureDim});
+  const int gj1 = std::min({target.by1 * brick, dimLy, gj0 + maxTextureDim});
+  const int gk1 = std::min({target.bz1 * brick, dimLz, gk0 + maxTextureDim});
+
+  // 区间为空 → 无块可重组。
+  if (gi1 <= gi0 || gj1 <= gj0 || gk1 <= gk0) return nullptr;
+
+  const int outNx = std::max(1, gi1 - gi0);
+  const int outNy = std::max(1, gj1 - gj0);
+  const int outNz = std::max(1, gk1 - gk0);
+
+  // 世界几何（按 level + exagg）：
+  //   spacing = meta.spacing × 2^level（y/z 再 × exagg）；
+  //   origin  = meta.origin + 区间起始体素 × spacing。
+  const double sc = static_cast<double>(std::int64_t(1) << level);  // 2^level
+  const double sp[3] = {meta.spacing[0] * sc, meta.spacing[1] * sc * exagg,
+                        meta.spacing[2] * sc * exagg};
+  const double org[3] = {meta.origin[0] + static_cast<double>(gi0) * sp[0],
+                         meta.origin[1] + static_cast<double>(gj0) * sp[1],
+                         meta.origin[2] + static_cast<double>(gk0) * sp[2]};
+
+  auto img = vtkSmartPointer<vtkImageData>::New();
+  img->SetDimensions(outNx, outNy, outNz);
+  img->SetOrigin(org[0], org[1], org[2]);
+  img->SetSpacing(sp[0], sp[1], sp[2]);
+
+  vtkNew<vtkShortArray> arr;
+  arr->SetName("v");
+  const vtkIdType total = static_cast<vtkIdType>(outNx) * outNy * outNz;
+  arr->SetNumberOfTuples(total);
+
+  // 遍历区间覆盖的 level 块，按块内 (i 最快、k 最慢) 布局把每体素写入子体对应位置。
+  // 块内布局与 readBrick / vtkImageData 点序一致。
+  const int bx0 = gi0 / brick, bx1 = (gi1 + brick - 1) / brick;
+  const int by0 = gj0 / brick, by1 = (gj1 + brick - 1) / brick;
+  const int bz0 = gk0 / brick, bz1 = (gk1 + brick - 1) / brick;
+
+  for (int bz = bz0; bz < bz1; ++bz) {
+    const int k0 = bz * brick;
+    const int bd = std::min(brick, dimLz - k0);
+    for (int by = by0; by < by1; ++by) {
+      const int j0 = by * brick;
+      const int bh = std::min(brick, dimLy - j0);
+      for (int bx = bx0; bx < bx1; ++bx) {
+        const int i0 = bx * brick;
+        const int bw = std::min(brick, dimLx - i0);
+        const std::vector<std::int16_t> raw = store.readBrick(level, bx, by, bz);
+
+        // 块内体素全局索引 (i0+ii, j0+jj, k0+kk)；只写落在子体区间 [g*0,g*1) 内的。
+        for (int kk = 0; kk < bd; ++kk) {
+          const int gk = k0 + kk;
+          if (gk < gk0 || gk >= gk1) continue;
+          const int lk = gk - gk0;
+          for (int jj = 0; jj < bh; ++jj) {
+            const int gj = j0 + jj;
+            if (gj < gj0 || gj >= gj1) continue;
+            const int lj = gj - gj0;
+            // 该 (kk,jj) 行在 raw 内的起始偏移（i 最快）。
+            const std::size_t rowBase =
+                (static_cast<std::size_t>(kk) * bh + jj) * bw;
+            for (int ii = 0; ii < bw; ++ii) {
+              const int gi = i0 + ii;
+              if (gi < gi0 || gi >= gi1) continue;
+              const int li = gi - gi0;
+              const vtkIdType id =
+                  (static_cast<vtkIdType>(lk) * outNy + lj) * outNx + li;
+              arr->SetValue(id, raw[rowBase + ii]);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  img->GetPointData()->SetScalars(arr);
+  return img;
+}
+
+}  // namespace geopro::render
diff --git a/src/render/source/RegionReorganizer.hpp b/src/render/source/RegionReorganizer.hpp
new file mode 100644
index 0000000..10d3ec2
--- /dev/null
+++ b/src/render/source/RegionReorganizer.hpp
@@ -0,0 +1,44 @@
+#pragma once
+#include <vtkImageData.h>
+#include <vtkSmartPointer.h>
+
+#include "data/store/ChunkedVolumeStore.hpp"
+
+namespace geopro::render {
+
+// 要重组的目标区域（C1 selectLod 选出的 LOD level + 视野内 brick 区间 + 垂向夸张）。
+//   level：LOD 层（0=最细）。
+//   [bx0,bx1) [by0,by1) [bz0,bz1)：该 level 要重组的 brick 区间（半开）。
+//   exagg：垂向夸张（烘焙进 y/z 的 spacing/origin）。
+// C2 ViewAdaptiveVolumeSource 与 C3 AsyncRegionBuilder 共用此结构（单一真源）。
+struct RegionTarget {
+  int level = 0;
+  int bx0 = 0, bx1 = 0;
+  int by0 = 0, by1 = 0;
+  int bz0 = 0, bz1 = 0;
+  double exagg = 1.0;
+
+  bool operator==(const RegionTarget& o) const {
+    return level == o.level && bx0 == o.bx0 && bx1 == o.bx1 && by0 == o.by0 &&
+           by1 == o.by1 && bz0 == o.bz0 && bz1 == o.bz1 && exagg == o.exagg;
+  }
+  bool operator!=(const RegionTarget& o) const { return !(*this == o); }
+};
+
+// 重组核（公共纯函数，单一真源；headless、不需 GL 上下文）。
+//
+// 把 store 中 [target] 指定的 level + brick 区间重组为【单张 VTK_SHORT
+// vtkImageData】，带世界 origin/spacing（按 level + exagg）：
+//   spacing = meta.spacing × 2^level（y/z 再 × exagg）；
+//   origin  = meta.origin + 区间起始体素 × spacing。
+//
+// 区间裁剪（与 C1 hpp 契约逐字一致）：各轴起点 = b0*brick；终点 =
+//   min(b1*brick, dimL, 起点 + maxTextureDim)——即使 brick > maxTextureDim
+//   也按体素上限再裁，恒 ≤ maxTextureDim。
+//
+// 区间为空（任一轴 b1<=b0）→ 返回 nullptr。
+vtkSmartPointer<vtkImageData> reorganizeRegion(
+    const geopro::data::ChunkedVolumeStore& store, const RegionTarget& target,
+    int maxTextureDim = 16384);
+
+}  // namespace geopro::render
diff --git a/src/render/source/ViewAdaptiveVolumeSource.cpp b/src/render/source/ViewAdaptiveVolumeSource.cpp
index 08c4e11..11260cd 100644
--- a/src/render/source/ViewAdaptiveVolumeSource.cpp
+++ b/src/render/source/ViewAdaptiveVolumeSource.cpp
@@ -1,26 +1,11 @@
 #include "source/ViewAdaptiveVolumeSource.hpp"
 
-#include <algorithm>
-#include <array>
-#include <cstdint>
-
 #include <vtkCamera.h>
-#include <vtkNew.h>
-#include <vtkPointData.h>
-#include <vtkShortArray.h>
+
+#include "source/RegionReorganizer.hpp"
 
 namespace geopro::render {
 
-namespace {
-
-// 该 level 某轴体素维度 = ceil(n / 2^level)，至少 1（与 C1/store 同口径）。
-int dimAtLevel(int n, int level) {
-  const int d = (n + (1 << level) - 1) >> level;
-  return d > 0 ? d : 1;
-}
-
-}  // namespace
-
 ViewAdaptiveVolumeSource::ViewAdaptiveVolumeSource(const std::string& storeDir,
                                                    double exagg)
     : store_(storeDir), meta_(store_.meta()), exagg_(exagg > 0 ? exagg : 1.0) {}
@@ -65,93 +50,19 @@ void ViewAdaptiveVolumeSource::updateView(const CameraView& cam,
     current_ = nullptr;
     return;
   }
-  const int level = sel.level;
-  lastLevel_ = level;
+  lastLevel_ = sel.level;
 
-  const int brick = meta_.brick;
-  const int dimLx = dimAtLevel(meta_.nx, level);
-  const int dimLy = dimAtLevel(meta_.ny, level);
-  const int dimLz = dimAtLevel(meta_.nz, level);
-
-  // 重组单纹理某轴范围（与 C1 hpp 契约逐字一致）：
-  //   起点 = b0*brick；终点 = min(b1*brick, dimL, 起点 + maxTextureDim)。
-  // 即使 brick > maxTextureDim（单块超限），也按体素上限再裁 → 恒 ≤ maxTextureDim。
-  const int gi0 = sel.bx0 * brick;
-  const int gj0 = sel.by0 * brick;
-  const int gk0 = sel.bz0 * brick;
-  const int gi1 = std::min({sel.bx1 * brick, dimLx, gi0 + maxTextureDim_});
-  const int gj1 = std::min({sel.by1 * brick, dimLy, gj0 + maxTextureDim_});
-  const int gk1 = std::min({sel.bz1 * brick, dimLz, gk0 + maxTextureDim_});
-
-  const int outNx = std::max(1, gi1 - gi0);
-  const int outNy = std::max(1, gj1 - gj0);
-  const int outNz = std::max(1, gk1 - gk0);
-
-  // 世界几何（按 level + exagg）：
-  //   spacing = meta.spacing × 2^level（y/z 再 × exagg）；
-  //   origin  = meta.origin + 区间起始体素 × spacing。
-  const double sc = static_cast<double>(std::int64_t(1) << level);  // 2^level
-  const double sp[3] = {meta_.spacing[0] * sc, meta_.spacing[1] * sc * exagg_,
-                        meta_.spacing[2] * sc * exagg_};
-  const double org[3] = {meta_.origin[0] + static_cast<double>(gi0) * sp[0],
-                         meta_.origin[1] + static_cast<double>(gj0) * sp[1],
-                         meta_.origin[2] + static_cast<double>(gk0) * sp[2]};
-
-  auto img = vtkSmartPointer<vtkImageData>::New();
-  img->SetDimensions(outNx, outNy, outNz);
-  img->SetOrigin(org[0], org[1], org[2]);
-  img->SetSpacing(sp[0], sp[1], sp[2]);
-
-  vtkNew<vtkShortArray> arr;
-  arr->SetName("v");
-  const vtkIdType total = static_cast<vtkIdType>(outNx) * outNy * outNz;
-  arr->SetNumberOfTuples(total);
-
-  // 遍历区间覆盖的 level 块，按块内 (i 最快、k 最慢) 布局把每体素写入子体对应位置。
-  // 块内布局与 readBrick / vtkImageData 点序一致。
-  const int bx0 = gi0 / brick, bx1 = (gi1 + brick - 1) / brick;
-  const int by0 = gj0 / brick, by1 = (gj1 + brick - 1) / brick;
-  const int bz0 = gk0 / brick, bz1 = (gk1 + brick - 1) / brick;
-
-  for (int bz = bz0; bz < bz1; ++bz) {
-    const int k0 = bz * brick;
-    const int bd = std::min(brick, dimLz - k0);
-    for (int by = by0; by < by1; ++by) {
-      const int j0 = by * brick;
-      const int bh = std::min(brick, dimLy - j0);
-      for (int bx = bx0; bx < bx1; ++bx) {
-        const int i0 = bx * brick;
-        const int bw = std::min(brick, dimLx - i0);
-        const std::vector<std::int16_t> raw = store_.readBrick(level, bx, by, bz);
-
-        // 块内体素全局索引 (i0+ii, j0+jj, k0+kk)；只写落在子体区间 [g*0,g*1) 内的。
-        for (int kk = 0; kk < bd; ++kk) {
-          const int gk = k0 + kk;
-          if (gk < gk0 || gk >= gk1) continue;
-          const int lk = gk - gk0;
-          for (int jj = 0; jj < bh; ++jj) {
-            const int gj = j0 + jj;
-            if (gj < gj0 || gj >= gj1) continue;
-            const int lj = gj - gj0;
-            // 该 (kk,jj) 行在 raw 内的起始偏移（i 最快）。
-            const std::size_t rowBase =
-                (static_cast<std::size_t>(kk) * bh + jj) * bw;
-            for (int ii = 0; ii < bw; ++ii) {
-              const int gi = i0 + ii;
-              if (gi < gi0 || gi >= gi1) continue;
-              const int li = gi - gi0;
-              const vtkIdType id =
-                  (static_cast<vtkIdType>(lk) * outNy + lj) * outNx + li;
-              arr->SetValue(id, raw[rowBase + ii]);
-            }
-          }
-        }
-      }
-    }
-  }
-
-  img->GetPointData()->SetScalars(arr);
-  current_ = img;
+  // C2 重组改委托公共重组核 reorganizeRegion（DRY，C3 AsyncRegionBuilder 同源）。
+  RegionTarget target{};
+  target.level = sel.level;
+  target.bx0 = sel.bx0;
+  target.bx1 = sel.bx1;
+  target.by0 = sel.by0;
+  target.by1 = sel.by1;
+  target.bz0 = sel.bz0;
+  target.bz1 = sel.bz1;
+  target.exagg = exagg_;
+  current_ = reorganizeRegion(store_, target, maxTextureDim_);
 }
 
 std::vector<vtkSmartPointer<vtkImageData>>
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 6faff58..e50fdf4 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -128,6 +128,8 @@ target_sources(geopro_tests PRIVATE render/test_outofcore_source.cpp)
 target_sources(geopro_tests PRIVATE render/test_view_adaptive_lod.cpp)
 # ViewAdaptiveVolumeSource(C2)：用 C1 selectLod 选层选区→从分块存储重组当前视野区域为单张 VTK_SHORT image(各轴≤16384/世界 origin/spacing 按 level+exagg/体素位置与 store 一致)。headless 不需 GPU。
 target_sources(geopro_tests PRIVATE render/test_view_adaptive_source.cpp)
+# AsyncRegionBuilder(C3-1)：后台 worker 调公共重组核 reorganizeRegion 重组视野区域→单图，主线程非阻塞 takeLatest 取最新就绪(supersede/析构干净 join/并发不崩/非阻塞)。真线程不需 GPU。
+target_sources(geopro_tests PRIVATE render/test_async_region_builder.cpp)
 target_link_libraries(geopro_tests PRIVATE geopro_render ${VTK_LIBRARIES})
 vtk_module_autoinit(TARGETS geopro_tests MODULES ${VTK_LIBRARIES})
 
diff --git a/tests/render/test_async_region_builder.cpp b/tests/render/test_async_region_builder.cpp
new file mode 100644
index 0000000..b828890
--- /dev/null
+++ b/tests/render/test_async_region_builder.cpp
@@ -0,0 +1,216 @@
+// AsyncRegionBuilder(C3) headless 测试（真线程，无需 GPU）：
+//   后台 worker 调公共重组核 reorganizeRegion 从分块 store 重组 RegionTarget→单张
+//   VTK_SHORT image；主线程非阻塞 takeLatest 取最新就绪。
+//
+// 验：就绪内容 == 同步重组逐体素一致 / supersede 收敛最新 / 析构忙时干净 join /
+//     并发数百次不崩不死锁 / takeLatest 非阻塞。
+
+#include "render/source/AsyncRegionBuilder.hpp"
+#include "render/source/RegionReorganizer.hpp"
+
+#include "core/algo/GprVolumeBuilder.hpp"
+#include "data/store/ChunkedVolumeStore.hpp"
+
+#include <vtkImageData.h>
+#include <vtkPointData.h>
+#include <vtkShortArray.h>
+
+#include <chrono>
+#include <filesystem>
+#include <thread>
+
+#include <gtest/gtest.h>
+
+using namespace geopro;
+using geopro::render::AsyncRegionBuilder;
+using geopro::render::RegionTarget;
+using geopro::render::reorganizeRegion;
+
+namespace {
+
+// 造一个含金字塔的 store：值 = 全局 (i+j+k)%1000（便于校验块定位），非 64 整除
+// 维度以含边缘块。返回 store 目录。与 C2 测试同口径。
+std::string makePyramidStore(const std::string& dir, int nx, int ny, int nz,
+                             int brick, int levels) {
+  std::filesystem::remove_all(dir);
+  core::BuiltI16 b;
+  b.vol = core::ScalarVolumeI16(nx, ny, nz);
+  for (int k = 0; k < nz; ++k)
+    for (int j = 0; j < ny; ++j)
+      for (int i = 0; i < nx; ++i)
+        b.vol.at(i, j, k) = static_cast<short>((i + j + k) % 1000);
+  b.quant = {1.0, 0.0};
+  b.origin = {{1, 2, 3}};
+  b.spacing = {{0.5, 0.5, 0.2}};
+  b.vminPhys = 0;
+  b.vmaxPhys = 1000;
+  data::ChunkedVolumeStore::write(dir, b, brick);
+  {
+    data::ChunkedVolumeStore s(dir);
+    s.buildPyramid(levels);
+  }
+  return dir;
+}
+
+void sleepMs(int ms) {
+  std::this_thread::sleep_for(std::chrono::milliseconds(ms));
+}
+
+// 轮询等就绪（有超时上限，避免卡死）。
+vtkSmartPointer<vtkImageData> waitReady(AsyncRegionBuilder& b, int maxTries = 500,
+                                        int stepMs = 5) {
+  vtkSmartPointer<vtkImageData> img;
+  for (int i = 0; i < maxTries && img == nullptr; ++i) {
+    img = b.takeLatest();
+    if (img == nullptr) sleepMs(stepMs);
+  }
+  return img;
+}
+
+// 两图逐体素相等（dims/类型/标量）。
+bool imagesEqual(vtkImageData* a, vtkImageData* b) {
+  if (a == nullptr || b == nullptr) return false;
+  int da[3], db[3];
+  a->GetDimensions(da);
+  b->GetDimensions(db);
+  if (da[0] != db[0] || da[1] != db[1] || da[2] != db[2]) return false;
+  auto* aa = vtkShortArray::SafeDownCast(a->GetPointData()->GetScalars());
+  auto* ba = vtkShortArray::SafeDownCast(b->GetPointData()->GetScalars());
+  if (aa == nullptr || ba == nullptr) return false;
+  const vtkIdType n = aa->GetNumberOfTuples();
+  if (n != ba->GetNumberOfTuples()) return false;
+  for (vtkIdType i = 0; i < n; ++i)
+    if (aa->GetValue(i) != ba->GetValue(i)) return false;
+  return true;
+}
+
+RegionTarget makeTarget(int level, int bx0, int bx1, int by0, int by1, int bz0,
+                        int bz1, double exagg = 1.0) {
+  RegionTarget t{};
+  t.level = level;
+  t.bx0 = bx0;
+  t.bx1 = bx1;
+  t.by0 = by0;
+  t.by1 = by1;
+  t.bz0 = bz0;
+  t.bz1 = bz1;
+  t.exagg = exagg;
+  return t;
+}
+
+}  // namespace
+
+// ── 就绪内容 == 同步重组逐体素一致 ─────────────────────────────────────────
+TEST(AsyncRegionBuilder, ReconstructsRequestedTargetMatchesSync) {
+  const auto dir =
+      (std::filesystem::temp_directory_path() / "gpr_arb_match").string();
+  makePyramidStore(dir, 200, 80, 60, 64, 3);
+
+  const RegionTarget t = makeTarget(1, 0, 2, 0, 1, 0, 1, 1.0);
+
+  // 同步参考：同一重组核对同一 target。
+  data::ChunkedVolumeStore refStore(dir);
+  vtkSmartPointer<vtkImageData> sync = reorganizeRegion(refStore, t, 16384);
+  ASSERT_NE(sync.Get(), nullptr);
+
+  AsyncRegionBuilder b(dir);
+  b.requestTarget(t);
+  vtkSmartPointer<vtkImageData> async = waitReady(b);
+  ASSERT_NE(async.Get(), nullptr);
+
+  EXPECT_EQ(async->GetScalarType(), VTK_SHORT);
+  EXPECT_TRUE(imagesEqual(async.Get(), sync.Get()));
+}
+
+// ── supersede：连发多个不同 target，最终收敛到最后一个，不崩不死锁 ────────────
+TEST(AsyncRegionBuilder, SupersedesStaleRequests) {
+  const auto dir =
+      (std::filesystem::temp_directory_path() / "gpr_arb_super").string();
+  makePyramidStore(dir, 200, 80, 60, 64, 3);
+
+  AsyncRegionBuilder b(dir);
+
+  // 连发若干不同 target，最后一个为期望最终态。
+  std::vector<RegionTarget> seq = {
+      makeTarget(2, 0, 1, 0, 1, 0, 1),
+      makeTarget(1, 0, 2, 0, 1, 0, 1),
+      makeTarget(0, 0, 1, 0, 1, 0, 1),
+      makeTarget(1, 1, 3, 0, 2, 0, 1),  // 最终态
+  };
+  const RegionTarget last = seq.back();
+  for (const auto& t : seq) b.requestTarget(t);
+
+  // 同步参考 = 最后一个 target。
+  data::ChunkedVolumeStore refStore(dir);
+  vtkSmartPointer<vtkImageData> sync = reorganizeRegion(refStore, last, 16384);
+  ASSERT_NE(sync.Get(), nullptr);
+
+  // 轮询直到 pending 清空且取到与最终态一致的结果（收敛）。
+  vtkSmartPointer<vtkImageData> latest;
+  for (int i = 0; i < 800; ++i) {
+    auto img = b.takeLatest();
+    if (img != nullptr) latest = img;
+    if (latest != nullptr && !b.hasPending()) break;
+    sleepMs(5);
+  }
+  ASSERT_NE(latest.Get(), nullptr);
+  EXPECT_FALSE(b.hasPending());
+  EXPECT_TRUE(imagesEqual(latest.Get(), sync.Get()))
+      << "最终就绪结果应收敛到最后一个 target";
+}
+
+// ── 析构忙时干净 join：建后立即析构（worker 在忙）应不崩不死锁不泄漏 ──────────
+TEST(AsyncRegionBuilder, DestructorJoinsCleanly) {
+  const auto dir =
+      (std::filesystem::temp_directory_path() / "gpr_arb_dtor").string();
+  makePyramidStore(dir, 200, 80, 60, 64, 3);
+
+  for (int rep = 0; rep < 20; ++rep) {
+    AsyncRegionBuilder b(dir);
+    // 立刻发请求让 worker 忙起来，随即析构。
+    b.requestTarget(makeTarget(0, 0, 3, 0, 2, 0, 1));
+    b.requestTarget(makeTarget(1, 0, 2, 0, 1, 0, 1));
+    // 不等待，直接离开作用域析构（必须干净 join）。
+  }
+  SUCCEED();  // 到这里没死锁/崩溃即通过。
+}
+
+// ── 并发压力：主线程循环 requestTarget + takeLatest 数百次，worker 并发，不崩 ──
+TEST(AsyncRegionBuilder, ConcurrentStress) {
+  const auto dir =
+      (std::filesystem::temp_directory_path() / "gpr_arb_stress").string();
+  makePyramidStore(dir, 200, 80, 60, 64, 3);
+
+  AsyncRegionBuilder b(dir);
+  int gotCount = 0;
+  for (int i = 0; i < 400; ++i) {
+    const int lvl = i % 3;
+    const int bx1 = 1 + (i % 2);
+    b.requestTarget(makeTarget(lvl, 0, bx1, 0, 1, 0, 1));
+    auto img = b.takeLatest();  // 非阻塞
+    if (img != nullptr) ++gotCount;
+  }
+  // 排空：等到最后一批就绪。
+  auto fin = waitReady(b);
+  EXPECT_NE(fin.Get(), nullptr);
+  // 过程中至少取到过若干结果（功能层证明 worker 在产出）。
+  EXPECT_GE(gotCount, 0);  // 不强求次数，关键是不崩不死锁
+  SUCCEED();
+}
+
+// ── takeLatest 非阻塞：无结果时立即返回 nullptr，不等待 worker ───────────────
+TEST(AsyncRegionBuilder, TakeLatestNonBlockingWhenEmpty) {
+  const auto dir =
+      (std::filesystem::temp_directory_path() / "gpr_arb_nb").string();
+  makePyramidStore(dir, 128, 64, 48, 64, 2);
+
+  AsyncRegionBuilder b(dir);
+  // 未发任何请求 → 立即 nullptr（计时应极短）。
+  const auto t0 = std::chrono::steady_clock::now();
+  auto img = b.takeLatest();
+  const auto dtMs = std::chrono::duration_cast<std::chrono::milliseconds>(
+                        std::chrono::steady_clock::now() - t0)
+                        .count();
+  EXPECT_EQ(img.Get(), nullptr);
+  EXPECT_LT(dtMs, 100);  // 远小于任一次重组耗时，证明未阻塞等 worker
+}