diff --git a/example/Basic/rf_test.cpp b/example/Basic/rf_test.cpp
index d1efee0c..66632a7e 100644
--- a/example/Basic/rf_test.cpp
+++ b/example/Basic/rf_test.cpp
@@ -80,8 +80,15 @@ private:
 
 public:
 
-    TestApp(RenderFramework *rf):WorkObject(rf)
+    TestApp(RenderFramework *rf):WorkObject()
     {
+        Join(rf,rf->GetSwapchainRenderTarget());
+    }
+
+    void Join(RenderFramework *rf,IRenderTarget *rt)
+    {
+        WorkObject::Join(rf,rt);
+
         if(!InitAutoMaterial())
             return;
 
@@ -95,31 +102,21 @@ public:
     void Tick(double)override
     {}
 
-    void Render(double)
+    void Render(double delta_time,graph::RenderCmdBuffer *cmd)
     {
-        //WorkObject是工作对象，不是渲染对象，所以不应该直接自动指定RenderTarget，更不能直接指定RenderCmdBuffer
+        if(!cmd)
+            return;
 
-        //目前这里只是为了测试，所以这样写
+        //这个使用完全不合理，录制CMD和推送swapchain是两回事，需要分开操作。
+        //比如场景有的物件分静态和动态
 
-        RenderFramework *rf=GetRenderFramework();
-        SwapchainModule *sm=rf->GetSwapchainModule();
+        //可能静态物件就全部一次性录制好，而动态物件则是每帧录制
 
-        RenderCmdBuffer *cb=sm->BeginRender();       //这里会有AcquireNextImage操作
-        if(cb)
-        {
-            //这个使用完全不合理，录制CMD和推送swapchain是两回事，需要分开操作。
-            //比如场景有的物件分静态和动态
+        cmd->SetClearColor(0,clear_color);
 
-            //可能静态物件就全部一次性录制好，而动态物件则是每帧录制
-
-            cb->SetClearColor(0,clear_color);
-             
-            cb->BeginRenderPass();
-                cb->Render(render_obj);
-            cb->EndRenderPass();
-
-            sm->EndRender();             //这里会Submit和PresentBackbuffer
-        }
+        cmd->BeginRenderPass();
+            cmd->Render(render_obj);
+        cmd->EndRenderPass();
     }
 };//class TestApp:public VulkanApplicationFramework
 
@@ -130,7 +127,20 @@ int main(int,char **)
     if(!rf.Init(SCREEN_WIDTH,SCREEN_HEIGHT))
         return(-1);
 
-    WorkManager wm(&rf);
+    // RenderFramework存在于外部，提供的是整体的渲染控制。
 
-    wm.Start(new TestApp(&rf));
+    // WorkManager是提供一个工作业务管理，但开发者并不一定要使用它，所以我们不将它们整合在一起。
+
+    SwapchainWorkManager wm(&rf);
+
+    wm.Run(new TestApp(&rf));
+
+    // WorkObject被定义为工作对象，所有的渲染控制都需要被写在WorkObject的Render函数下。
+
+    // 但我们认为游戏开发者不应该关注如何控制渲染，而应该关注如何处理游戏逻辑.
+    // 所以我们在WorkObject的基础上再提供RenderWorkObject派生类，用于直接封装好的渲染场景树控制。
+    // 
+    // 开发者仅需要将要渲染的物件放置于场景树即可。
+
+    // 但开发者也可以直接使用WorkObject，自行管理这些事。
 }
diff --git a/example/common/WorkManager.cpp b/example/common/WorkManager.cpp
index 4c17d939..220ebba6 100644
--- a/example/common/WorkManager.cpp
+++ b/example/common/WorkManager.cpp
@@ -1,5 +1,6 @@
 #pragma once
 #include"WorkManager.h"
+#include<hgl/graph/VKRenderTarget.h>
 
 namespace hgl
 {
@@ -18,17 +19,33 @@ namespace hgl
     {
         double delta_time=cur_time-last_render_time;
 
-        if(delta_time>=frame_time)
+        if(delta_time>=frame_time||wo->IsRenderDirty())
         {
             last_render_time=cur_time;
             wo->Render(delta_time);
         }
     }
 
-    void WorkManager::Run()
+    void SwapchainWorkManager::Render(WorkObject *wo)
     {
-        if(!cur_work_object)
-            return;
+        graph::IRenderTarget *rt=swpachain_module->AcquireNextImage();
+
+        wo->MarkRenderDirty();      //临时的，未来会被更好的机制替代
+        WorkManager::Render(wo);
+
+        rt->WaitQueue();
+        rt->WaitFence();
+    }
+
+    void WorkManager::Run(WorkObject *wo)
+    {
+        if(!wo)return;
+
+        last_update_time=last_render_time=0;
+
+        cur_work_object=wo;
+
+        wo->Join(render_framework,render_framework->GetSwapchainRenderTarget());
 
         Window *win=render_framework->GetWindow();
         graph::GPUDevice *dev=render_framework->GetDevice();
@@ -50,17 +67,4 @@ namespace hgl
                 break;
         }
     }
-
-    void WorkManager::Start(WorkObject *wo)
-    {
-        if(!wo)return;
-
-        last_update_time=last_render_time=0;
-
-        cur_work_object=wo;
-
-        wo->Join(render_framework);
-
-        Run();
-    }
 }//namespcae hgl
diff --git a/example/common/WorkManager.h b/example/common/WorkManager.h
index 2695d3af..531c820e 100644
--- a/example/common/WorkManager.h
+++ b/example/common/WorkManager.h
@@ -3,6 +3,9 @@
 
 namespace hgl
 {
+    /**
+    * 工作管理器，管理一个序列的WorkObject<br>
+    */
     class WorkManager
     {
         graph::RenderFramework *render_framework;
@@ -35,10 +38,24 @@ namespace hgl
         }
 
         void Tick(WorkObject *wo);
-        void Render(WorkObject *wo);
 
-        void Run();
+        virtual void Render(WorkObject *wo);
 
-        void Start(WorkObject *wo);
+        void Run(WorkObject *wo);
     };//class WorkManager
+
+    class SwapchainWorkManager:public WorkManager
+    {
+        graph::SwapchainModule *swpachain_module;
+
+    public:
+
+        SwapchainWorkManager(graph::RenderFramework *rf):WorkManager(rf)
+        {
+            swpachain_module=rf->GetSwapchainModule();
+        }
+        ~SwapchainWorkManager()=default;
+
+        void Render(WorkObject *wo) override;
+    };
 }//namespcae hgl
diff --git a/example/common/WorkObject.h b/example/common/WorkObject.h
index 1cc7b246..39181fa8 100644
--- a/example/common/WorkObject.h
+++ b/example/common/WorkObject.h
@@ -2,18 +2,25 @@
 #include<hgl/graph/RenderFramework.h>
 #include<hgl/graph/module/SwapchainModule.h>
 #include<hgl/graph/VKRenderResource.h>
+#include<hgl/graph/VKRenderTarget.h>
 #include<hgl/type/object/TickObject.h>
 #include<hgl/Time.h>
+//#include<iostream>
 
 namespace hgl
 {
+    /**
+    * 工作对象</p>
+    */
     class WorkObject:public TickObject
     {
         graph::RenderFramework *render_framework=nullptr;
+        graph::IRenderTarget *cur_render_target=nullptr;
 
         bool destroy_flag=false;
 
         bool renderable=true;
+        bool render_dirty=true;
 
     protected:
 
@@ -29,27 +36,58 @@ namespace hgl
 
         const bool IsDestroy()const{return destroy_flag;}
         const bool IsRenderable()const{return renderable;}
+        const bool IsRenderDirty()const{return render_dirty;}
 
         void MarkDestory(){destroy_flag=true;}
         void SetRenderable(bool r){renderable=r;}
+        void MarkRenderDirty(){render_dirty=true;}
 
     public:
 
-        WorkObject(graph::RenderFramework *rf)
-        {
-            Join(rf);
-        }
+        WorkObject()=default;
         virtual ~WorkObject()=default;
 
-        virtual void Join(graph::RenderFramework *rf)
+        virtual void Join(graph::RenderFramework *rf,graph::IRenderTarget *rt)
         {
             if(!rf)return;
             if(render_framework==rf)return;
 
             render_framework=rf;
+            cur_render_target=rt;
             db=rf->GetRenderResource();
         }
 
-        virtual void Render(double delta_time)=0;
+        virtual void Render(double delta_time,graph::RenderCmdBuffer *cmd)=0;
+
+        virtual void Render(double delta_time)
+        {
+            if(!cur_render_target)
+            {
+                //std::cerr<<"WorkObject::Render,cur_render_target=nullptr"<<std::endl;
+                return;
+            }
+
+            //std::cout<<"WorkObject::Render begin, render_dirty="<<(render_dirty?"true":"false")<<std::endl;
+
+            if(render_dirty)
+            {
+                graph::RenderCmdBuffer *cmd=cur_render_target->BeginRender();
+
+                if(!cmd)
+                {
+                    //std::cerr<<"WorkObject::Render,cur_render_target->BeginRender()=nullptr"<<std::endl;
+                    return;
+                }
+
+                Render(delta_time,cmd);
+
+                cur_render_target->EndRender();
+                cur_render_target->Submit();
+
+                render_dirty=false;
+            }
+
+            //std::cout<<"WorkObject::Render End"<<std::endl;
+        }
     };//class WorkObject
 }//namespcae hgl
diff --git a/inc/hgl/graph/VKQueue.h b/inc/hgl/graph/VKQueue.h
index 3d335361..d32ef5d6 100644
--- a/inc/hgl/graph/VKQueue.h
+++ b/inc/hgl/graph/VKQueue.h
@@ -1,4 +1,4 @@
-#ifndef HGL_GRAPH_VULKAN_SUBMIT_QUEUE_INCLUDE
+#ifndef HGL_GRAPH_VULKAN_SUBMIT_QUEUE_INCLUDE
 #define HGL_GRAPH_VULKAN_SUBMIT_QUEUE_INCLUDE
 
 #include<hgl/graph/VK.h>
@@ -31,8 +31,16 @@ public:
     
     VkResult Present(const VkPresentInfoKHR *pi){return vkQueuePresentKHR(queue,pi);}
 
+    /**
+    * 等待Submit的队列完成操作。这个操作会阻塞当前线程，所以在Submit后请不要立即使用它。而是在下一次队列提交前再做这个操作。
+    */
     bool WaitQueue();
+
+    /**
+    * 等待Queue命令执行完成的fence信号
+    */
     bool WaitFence(const bool wait_all=true,const uint64_t time_out=HGL_NANO_SEC_PER_SEC);
+
     bool Submit(const VkCommandBuffer *cmd_buf,const uint32_t count,Semaphore *wait_sem,Semaphore *complete_sem);
     bool Submit(GPUCmdBuffer *cmd_buf,Semaphore *wait_sem,Semaphore *complete_sem);
 };//class DeviceQueue
diff --git a/inc/hgl/graph/VKRenderTarget.h b/inc/hgl/graph/VKRenderTarget.h
index 19ec6ba4..494a0eda 100644
--- a/inc/hgl/graph/VKRenderTarget.h
+++ b/inc/hgl/graph/VKRenderTarget.h
@@ -7,6 +7,7 @@
 #include<hgl/graph/VKQueue.h>
 #include<hgl/graph/VKPipeline.h>
 #include<hgl/graph/VKCommandBuffer.h>
+//#include<iostream>
 
 VK_NAMESPACE_BEGIN
 /**
@@ -54,6 +55,9 @@ public: // Command Buffer
 
     virtual bool                WaitQueue           ()=0;
     virtual bool                WaitFence           ()=0;
+
+    virtual RenderCmdBuffer *   BeginRender         ()=0;
+    virtual void                EndRender           ()=0;
 };//class IRenderTarget
 
 struct RenderTargetData
@@ -136,6 +140,26 @@ public: // Command Buffer
 
     bool                WaitQueue           ()override{return data->queue->WaitQueue();}
     bool                WaitFence           ()override{return data->queue->WaitFence();}
+
+public:
+
+    virtual RenderCmdBuffer *BeginRender()override
+    {
+        if(!data->cmd_buf)
+            return(nullptr);
+
+        data->cmd_buf->Begin();
+        data->cmd_buf->BindFramebuffer(data->fbo);
+        return data->cmd_buf;
+    }
+
+    virtual void EndRender() override
+    {
+        if(!data->cmd_buf)
+            return;
+
+        data->cmd_buf->End();
+    }
 };//class RenderTarget
 
 /**
@@ -212,6 +236,20 @@ public: // Command Buffer
 
     bool                WaitQueue           ()override{return rt_list[current_frame]->WaitQueue();}
     bool                WaitFence           ()override{return rt_list[current_frame]->WaitFence();}
+
+public:
+
+    virtual RenderCmdBuffer *BeginRender()override
+    {
+        //std::cout<<"Begin Render frame="<<current_frame<<std::endl;
+        return rt_list[current_frame]->BeginRender();
+    }
+
+    virtual void EndRender() override
+    {
+        //std::cout<<"End Render frame="<<current_frame<<std::endl;
+        rt_list[current_frame]->EndRender();
+    }
 };//class MFRenderTarget
 
 /**
@@ -238,13 +276,8 @@ public:
 
 public:
 
-    RenderCmdBuffer *AcquireNextImage();             ///<获取下一帧的索引
+    IRenderTarget *AcquireNextImage();             ///<获取下一帧的索引
 
-    bool    PresentBackbuffer();            ///<推送后台画面到前台
-
-    bool    Submit()override
-    {
-        return rt_list[current_frame]->Submit(present_complete_semaphore);
-    }
+    bool Submit()override;                         ///<提交当前帧的渲染，交推送到前台
 };//class SwapchainRenderTarget:public RenderTarget
 VK_NAMESPACE_END
diff --git a/inc/hgl/graph/module/SwapchainModule.h b/inc/hgl/graph/module/SwapchainModule.h
index 49d0b025..7c8fc8bf 100644
--- a/inc/hgl/graph/module/SwapchainModule.h
+++ b/inc/hgl/graph/module/SwapchainModule.h
@@ -33,9 +33,9 @@ public:
     SwapchainModule(GPUDevice *,TextureManager *tm,RenderTargetManager *rtm,RenderPassManager *rpm);
     virtual ~SwapchainModule();
 
-    RenderCmdBuffer *BeginRender();
+//    RenderCmdBuffer *BeginRender();
 
-    void EndRender();
+    //void EndRender();
 
 public:
 
@@ -44,6 +44,7 @@ public:
     const   VkExtent2D &            GetSwapchainSize()const{return sc_render_target->GetExtent();}
 
             SwapchainRenderTarget * GetRenderTarget ()const{return sc_render_target;}
+            IRenderTarget *         AcquireNextImage()const{return sc_render_target->AcquireNextImage();}
 };//class SwapchainModule:public GraphModule
 
 VK_NAMESPACE_END
diff --git a/res b/res
index e1a36d78..475d8ad4 160000
--- a/res
+++ b/res
@@ -1 +1 @@
-Subproject commit e1a36d78f0eead5f6bb65493432c4690637b991d
+Subproject commit 475d8ad43ceee084cd24f5d0bed59de9f6aa36fd
diff --git a/src/SceneGraph/Vulkan/VKQueue.cpp b/src/SceneGraph/Vulkan/VKQueue.cpp
index 7af7f758..6846133d 100644
--- a/src/SceneGraph/Vulkan/VKQueue.cpp
+++ b/src/SceneGraph/Vulkan/VKQueue.cpp
@@ -67,6 +67,10 @@ bool DeviceQueue::Submit(const VkCommandBuffer *cmd_buf,const uint32_t cb_count,
         submit_info.pWaitSemaphores     =nullptr;
     }
 
+    // wait 信号的意思是等待这个Image有效
+    // signal 则是这个queue已执行完成，和fence功能类似。
+    // 所以Wait信号一般是上一次的signal信号
+
     if(complete_sem)
     {
         cs=*complete_sem;
diff --git a/src/SceneGraph/Vulkan/VKSwapchainRenderTarget.cpp b/src/SceneGraph/Vulkan/VKSwapchainRenderTarget.cpp
index 4d6e684f..9b46022a 100644
--- a/src/SceneGraph/Vulkan/VKSwapchainRenderTarget.cpp
+++ b/src/SceneGraph/Vulkan/VKSwapchainRenderTarget.cpp
@@ -1,6 +1,7 @@
 #include<hgl/graph/VKRenderTarget.h>
 #include<hgl/graph/VKDevice.h>
 #include<hgl/graph/VKSemaphore.h>
+//#include<iostream>
 
 VK_NAMESPACE_BEGIN
 SwapchainRenderTarget::SwapchainRenderTarget(VkDevice dev,Swapchain *sc,Semaphore *pcs,RenderTarget **rtl):MFRenderTarget(sc->image_count,rtl)
@@ -16,6 +17,10 @@ SwapchainRenderTarget::SwapchainRenderTarget(VkDevice dev,Swapchain *sc,Semaphor
     present_info.pSwapchains        = &(swapchain->swap_chain);
    
     present_complete_semaphore=pcs;
+
+    VkSemaphore sem=*present_complete_semaphore;
+
+//    std::cout<<"present complete semaphore : "<<std::hex<<sem<<std::endl;
 }
 
 SwapchainRenderTarget::~SwapchainRenderTarget()
@@ -24,34 +29,44 @@ SwapchainRenderTarget::~SwapchainRenderTarget()
     delete swapchain;
 }
     
-RenderCmdBuffer *SwapchainRenderTarget::AcquireNextImage()
+IRenderTarget *SwapchainRenderTarget::AcquireNextImage()
 {
+    VkSemaphore sem=*present_complete_semaphore;
+
+    //std::cout<<"AcquireNextImage present_complete_semaphore : "<<std::hex<<sem<<std::endl;
+
     if(vkAcquireNextImageKHR(device,
                              swapchain->swap_chain,
                              UINT64_MAX,
-                             *present_complete_semaphore,
+                             sem,
                              VK_NULL_HANDLE,
                              &current_frame)!=VK_SUCCESS)
         return(nullptr);
 
-    SwapchainImage *sc_image=&(swapchain->sc_image[current_frame]);
+    //std::cerr<<"AcquireNextImage current_frame="<<current_frame<<std::endl;
 
-    sc_image->cmd_buf->Begin();
-    sc_image->cmd_buf->BindFramebuffer(sc_image->fbo);
-
-    return sc_image->cmd_buf;
+    return rt_list[current_frame];
 }
 
-bool SwapchainRenderTarget::PresentBackbuffer()
+bool SwapchainRenderTarget::Submit()
 {
+    IRenderTarget *rt=rt_list[current_frame];
+    
+    //std::cout<<"submit frame="<<current_frame<<std::endl;
+
+    if(!rt->Submit(present_complete_semaphore))
+        return(false);
+
     DeviceQueue *queue=GetQueue();
 
-    VkSemaphore wait_semaphores=*GetRenderCompleteSemaphore();
+    VkSemaphore wait_semaphores=*rt->GetRenderCompleteSemaphore();
 
     present_info.waitSemaphoreCount =1;
     present_info.pWaitSemaphores    =&wait_semaphores;
     present_info.pImageIndices      =&current_frame;
 
+//    std::cout<<"present frame="<<current_frame<<std::endl;
+
     VkResult result=queue->Present(&present_info);
     
     if (!((result == VK_SUCCESS) || (result == VK_SUBOPTIMAL_KHR))) 
diff --git a/src/SceneGraph/module/SwapchainModule.cpp b/src/SceneGraph/module/SwapchainModule.cpp
index 9f3c3e88..804ed539 100644
--- a/src/SceneGraph/module/SwapchainModule.cpp
+++ b/src/SceneGraph/module/SwapchainModule.cpp
@@ -6,6 +6,7 @@
 #include<hgl/graph/VKDeviceAttribute.h>
 #include<hgl/graph/VKRenderTarget.h>
 #include<hgl/graph/VKCommandBuffer.h>
+#include<hgl/graph/VKSemaphore.h>
 
 VK_NAMESPACE_BEGIN
 namespace
@@ -266,18 +267,18 @@ void SwapchainModule::OnResize(const VkExtent2D &extent)
 
     CreateSwapchainRenderTarget();
 }
-
-RenderCmdBuffer *SwapchainModule::BeginRender()
-{
-    return sc_render_target->AcquireNextImage();
-}
-
-void SwapchainModule::EndRender()
-{
-    sc_render_target->Submit();
-    sc_render_target->PresentBackbuffer();
-    sc_render_target->WaitQueue();
-    sc_render_target->WaitFence();
-}
+//
+//RenderCmdBuffer *SwapchainModule::BeginRender()
+//{
+//    return sc_render_target->AcquireNextImage();
+//}
+//
+//void SwapchainModule::EndRender()
+//{
+//    sc_render_target->Submit();
+//    sc_render_target->PresentBackbuffer();
+//    sc_render_target->WaitQueue();
+//    sc_render_target->WaitFence();
+//}
 
 VK_NAMESPACE_END