diff --git a/example/Vulkan/Geometry2D.cpp b/example/Vulkan/Geometry2D.cpp
index 84786941..67b74609 100644
--- a/example/Vulkan/Geometry2D.cpp
+++ b/example/Vulkan/Geometry2D.cpp
@@ -29,9 +29,6 @@ class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
-            SceneDB *           db                  =nullptr;
             SceneNode           render_root;
             RenderList          render_list;
 
@@ -45,16 +42,6 @@ private:
     vulkan::Buffer *            ubo_mvp             =nullptr;
 
     vulkan::Pipeline *          pipeline            =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
-
-public:
-
-    ~TestApp()
-    {
-        SAFE_CLEAR(db);
-
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
-    }
 
 private:
 
@@ -152,27 +139,7 @@ private:
 
         render_root.ExpendToList(&render_list);
 
-        return(true);
-    }
-
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-                cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-                    render_list.Render(cmd_buf[i]);
-                cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
+        BuildCommandBuffer(&render_list);
         return(true);
     }
 
@@ -183,10 +150,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
-        db=new SceneDB(device);
-
         if(!InitMaterial())
             return(false);
 
@@ -201,20 +164,8 @@ public:
         if(!InitScene())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
-
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 int main(int,char **)
diff --git a/example/Vulkan/Geometry3D.cpp b/example/Vulkan/Geometry3D.cpp
index 57a098c3..62d69248 100644
--- a/example/Vulkan/Geometry3D.cpp
+++ b/example/Vulkan/Geometry3D.cpp
@@ -10,16 +10,13 @@
 using namespace hgl;
 using namespace hgl::graph;
 
-constexpr uint32_t SCREEN_WIDTH=256;
-constexpr uint32_t SCREEN_HEIGHT=256;
+constexpr uint32_t SCREEN_WIDTH=128;
+constexpr uint32_t SCREEN_HEIGHT=128;
 
 class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
-    SceneDB *   db                  =nullptr;
     SceneNode   render_root;
     RenderList  render_list;
 
@@ -33,16 +30,6 @@ private:
     vulkan::Buffer *            ubo_world_matrix    =nullptr;
 
     vulkan::Pipeline *          pipeline_line       =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
-
-public:
-
-    ~TestApp()
-    {
-        SAFE_CLEAR(db);
-
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
-    }
 
 private:
 
@@ -73,34 +60,32 @@ private:
 
     void CreateRenderObject()
     {
-        {
-            struct PlaneGridCreateInfo pgci;
+        struct PlaneGridCreateInfo pgci;
 
-            pgci.coord[0].Set(-100,-100,0);
-            pgci.coord[1].Set( 100,-100,0);
-            pgci.coord[2].Set( 100, 100,0);
-            pgci.coord[3].Set(-100, 100,0);
+        pgci.coord[0].Set(-100,-100,0);
+        pgci.coord[1].Set( 100,-100,0);
+        pgci.coord[2].Set( 100, 100,0);
+        pgci.coord[3].Set(-100, 100,0);
 
-            pgci.step.u=20;
-            pgci.step.v=20;
+        pgci.step.u=20;
+        pgci.step.v=20;
 
-            pgci.side_step.u=10;
-            pgci.side_step.v=10;
+        pgci.side_step.u=10;
+        pgci.side_step.v=10;
 
-            pgci.color.Set(0.75,0,0,1);
-            pgci.side_color.Set(1,0,0,1);
+        pgci.color.Set(0.75,0,0,1);
+        pgci.side_color.Set(1,0,0,1);
 
-            ro_plane_grid[0]=CreatePlaneGrid(db,material,&pgci);
+        ro_plane_grid[0]=CreatePlaneGrid(db,material,&pgci);
 
-            pgci.color.Set(0,0.75,0,1);
-            pgci.side_color.Set(0,1,0,1);
+        pgci.color.Set(0,0.75,0,1);
+        pgci.side_color.Set(0,1,0,1);
 
-            ro_plane_grid[1]=CreatePlaneGrid(db,material,&pgci);
+        ro_plane_grid[1]=CreatePlaneGrid(db,material,&pgci);
 
-            pgci.color.Set(0,0,0.75,1);
-            pgci.side_color.Set(0,0,1,1);
-            ro_plane_grid[2]=CreatePlaneGrid(db,material,&pgci);
-        }
+        pgci.color.Set(0,0,0.75,1);
+        pgci.side_color.Set(0,0,1,1);
+        ro_plane_grid[2]=CreatePlaneGrid(db,material,&pgci);
     }
 
     bool InitUBO()
@@ -153,26 +138,7 @@ private:
         render_root.RefreshMatrix();
         render_root.ExpendToList(&render_list);
 
-        return(true);
-    }
-
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-            render_list.Render(cmd_buf[i]);
-            cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
+        BuildCommandBuffer(&render_list);
 
         return(true);
     }
@@ -184,10 +150,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
-        db=new SceneDB(device);
-
         InitCamera();
 
         if(!InitMaterial())
@@ -204,20 +166,8 @@ public:
         if(!InitScene())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
-
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 int main(int,char **)
diff --git a/example/Vulkan/LoadModel.cpp b/example/Vulkan/LoadModel.cpp
index a79a3416..ba7ed77e 100644
--- a/example/Vulkan/LoadModel.cpp
+++ b/example/Vulkan/LoadModel.cpp
@@ -4,9 +4,7 @@
 #include"VulkanAppFramework.h"
 #include<hgl/filesystem/FileSystem.h>
 #include<hgl/graph/InlineGeometry.h>
-#include<hgl/graph/SceneDB.h>
 #include<hgl/graph/RenderableInstance.h>
-#include<hgl/graph/RenderList.h>
 
 #include"AssimpLoaderMesh.h"
 #include<hgl/graph/VertexBuffer.h>
@@ -74,6 +72,7 @@ vulkan::Renderable *CreateMeshRenderable(SceneDB *db,vulkan::Material *mtl,const
     else
         render_obj->Set(db->CreateIBO32(mesh->indices32.GetCount(),mesh->indices32.GetData()));
 
+    db->Add(render_obj);
     return(render_obj);
 }
 
@@ -81,9 +80,6 @@ class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
-    SceneDB *   db                  =nullptr;
     SceneNode   render_root;
     RenderList  render_list;
 
@@ -95,21 +91,20 @@ private:
     vulkan::Buffer *            ubo_world_matrix    =nullptr;
 
     vulkan::Pipeline *          pipeline_line       =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
 
 private:
 
     ModelData *model_data;
 
     vulkan::Renderable **mesh_renderable;
+    RenderableInstance **mesh_renderable_instance;
 
 public:
 
     ~TestApp()
     {
-        SAFE_CLEAR(db);
-
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
+        delete[] mesh_renderable_instance;
+        delete[] mesh_renderable;
     }
 
 private:
@@ -151,11 +146,13 @@ private:
         const uint count=model_data->mesh_data.GetCount();
         MeshData **md=model_data->mesh_data.GetData();
 
-        mesh_renderable=new vulkan::Renderable *[count];
+        mesh_renderable         =new vulkan::Renderable *[count];
+        mesh_renderable_instance=new RenderableInstance *[count];
 
         for(uint i=0;i<count;i++)
         {
             mesh_renderable[i]=CreateMeshRenderable(db,material,*md);
+            mesh_renderable_instance[i]=db->CreateRenderableInstance(pipeline_line,descriptor_sets,mesh_renderable[i]);
             ++md;
         }
     }
@@ -200,7 +197,7 @@ private:
         return pipeline_line;
     }
 
-    void CreateRenderableInstance(SceneNode *scene_node,ModelSceneNode *model_node)
+    void CreateSceneNode(SceneNode *scene_node,ModelSceneNode *model_node)
     {
         scene_node->SetLocalMatrix(model_node->local_matrix);
 
@@ -210,7 +207,7 @@ private:
 
             for(uint i=0;i<count;i++)
             {
-                scene_node->Add(db->CreateRenderableInstance(pipeline_line,descriptor_sets,mesh_renderable[*mesh_index]));
+                scene_node->Add(mesh_renderable_instance[*mesh_index]);
 
                 ++mesh_index;
             }
@@ -222,7 +219,7 @@ private:
 
             for(uint i=0;i<count;i++)
             {
-                CreateRenderableInstance(scene_node->CreateSubNode(),*sub_model_node);
+                CreateSceneNode(scene_node->CreateSubNode(),*sub_model_node);
 
                 ++sub_model_node;
             }
@@ -231,32 +228,12 @@ private:
 
     bool InitScene()
     {
-        CreateRenderableInstance(&render_root,model_data->root_node);
+        CreateSceneNode(&render_root,model_data->root_node);
 
         render_root.RefreshMatrix();
         render_root.ExpendToList(&render_list);
 
-        return(true);
-    }
-
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-            render_list.Render(cmd_buf[i]);
-            cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
+        BuildCommandBuffer(&render_list);
         return(true);
     }
 
@@ -272,15 +249,9 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
-        db=new SceneDB(device);
-
         if(!InitMaterial())
             return(false);
 
-        CreateRenderObject();
-
         InitCamera();
 
         if(!InitUBO())
@@ -289,23 +260,13 @@ public:
         if(!InitPipeline())
             return(false);
 
+        CreateRenderObject();
+
         if(!InitScene())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
-
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 #ifdef _WIN32
diff --git a/example/Vulkan/SceneTree.cpp b/example/Vulkan/SceneTree.cpp
index 6894e0d7..e3f61b30 100644
--- a/example/Vulkan/SceneTree.cpp
+++ b/example/Vulkan/SceneTree.cpp
@@ -12,18 +12,15 @@
 using namespace hgl;
 using namespace hgl::graph;
 
-constexpr uint32_t SCREEN_WIDTH=256;
-constexpr uint32_t SCREEN_HEIGHT=256;
+constexpr uint32_t SCREEN_WIDTH=128;
+constexpr uint32_t SCREEN_HEIGHT=128;
 
 class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    double start_time;
+    double      start_time;
 
-    uint swap_chain_count=0;
-
-    SceneDB *   db                  =nullptr;
     SceneNode   render_root;
     RenderList  render_list;
 
@@ -37,7 +34,6 @@ private:
     vulkan::Buffer *            ubo_world_matrix    =nullptr;
 
     vulkan::Pipeline *          pipeline_line       =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
 
 public:
 
@@ -46,12 +42,7 @@ public:
         start_time=GetDoubleTime();
     }
 
-    ~TestApp()
-    {
-        SAFE_CLEAR(db);
-
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
-    }
+    ~TestApp()=default;
 
 private:
 
@@ -150,32 +141,14 @@ private:
                 cur_node->Add(ri,translate(0,0,size*n*1.01));
         }
 
+        render_root.RefreshMatrix();
+        render_list.Clear();
+        render_root.ExpendToList(&render_list);
+
+        BuildCommandBuffer(&render_list);
         return(true);
     }
 
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-        return BuildCommandBuffer();
-    }
-
-    bool BuildCommandBuffer()
-    {
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]->Begin();
-            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-            render_list.Render(cmd_buf[i]);
-            cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
-        return(true);
-    }
 
 public:
 
@@ -184,10 +157,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
-        db=new SceneDB(device);
-
         InitCamera();
 
         if(!InitMaterial())
@@ -204,17 +173,12 @@ public:
         if(!InitScene())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
-
         return(true);
     }
 
     void Draw() override
     {
-        vulkan::CommandBuffer *cb=cmd_buf[device->GetCurrentFrameIndices()];
-
-        Submit(*cb);
+        VulkanApplicationFramework::Draw();
 
         Matrix4f rot=rotate(GetDoubleTime()-start_time,camera.up_vector);
 
@@ -222,7 +186,7 @@ public:
         render_list.Clear();
         render_root.ExpendToList(&render_list);
 
-        BuildCommandBuffer();
+        BuildCommandBuffer(&render_list);
     }
 };//class TestApp:public VulkanApplicationFramework
 
diff --git a/example/Vulkan/VulkanAppFramework.h b/example/Vulkan/VulkanAppFramework.h
index e0ae24cd..dd021a47 100644
--- a/example/Vulkan/VulkanAppFramework.h
+++ b/example/Vulkan/VulkanAppFramework.h
@@ -15,6 +15,8 @@
 #include<hgl/graph/vulkan/VKFormat.h>
 #include<hgl/graph/vulkan/VKFramebuffer.h>
 #include<hgl/graph/vulkan/VKMaterial.h>
+#include<hgl/graph/SceneDB.h>
+#include<hgl/graph/RenderList.h>
 
 using namespace hgl;
 using namespace hgl::graph;
@@ -31,10 +33,23 @@ protected:
     vulkan::Device *            device          =nullptr;
     vulkan::ShaderModuleManage *shader_manage   =nullptr;
 
+private:
+
+            uint32_t            swap_chain_count=0;
+
+    vulkan::CommandBuffer **    cmd_buf         =nullptr;
+   
+protected:
+
+            SceneDB *           db              =nullptr;
+
 public:
 
     virtual ~VulkanApplicationFramework()
-    {   
+    {
+        SAFE_CLEAR(db);
+        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
+
         SAFE_CLEAR(shader_manage);
         SAFE_CLEAR(win);        //win中会删除device，所以必须放在instance前删除
         SAFE_CLEAR(inst);
@@ -67,9 +82,61 @@ public:
             return(false);
 
         shader_manage=device->CreateShaderModuleManage();
+
+        swap_chain_count = device->GetSwapChainImageCount();
+        {
+            cmd_buf = hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
+
+            for (uint i=0;i<swap_chain_count;i++)
+                cmd_buf[i]=device->CreateCommandBuffer();
+        }
+
+        db=new SceneDB(device);
+
         return(true);
     }
 
+    void BuildCommandBuffer(vulkan::Pipeline *p,vulkan::DescriptorSets *ds,vulkan::Renderable *r)
+    {
+        if(!p||!ds||!r)
+            return;
+
+        const vulkan::IndexBuffer *ib=r->GetIndexBuffer();
+
+        for(uint i=0;i<swap_chain_count;i++)
+        {
+            cmd_buf[i]->Begin();
+            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
+            cmd_buf[i]->Bind(p);
+            cmd_buf[i]->Bind(ds);
+            cmd_buf[i]->Bind(r);
+
+            if (ib)
+                cmd_buf[i]->DrawIndexed(ib->GetCount());
+            else
+                cmd_buf[i]->Draw(r->GetDrawCount());
+
+            cmd_buf[i]->EndRenderPass();
+            cmd_buf[i]->End();
+        }
+    }
+
+    void BuildCommandBuffer(RenderList *rl)
+    {
+        if(!rl)return;
+
+        for(uint i=0;i<swap_chain_count;i++)
+        {
+            cmd_buf[i]->Begin();
+            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
+            rl->Render(cmd_buf[i]);
+            cmd_buf[i]->EndRenderPass();
+            cmd_buf[i]->End();
+        }
+    }
+
+private:
+
     void AcquireNextFrame()
     {
         device->AcquireNextImage();
@@ -82,7 +149,14 @@ public:
         device->QueuePresent();
     }
 
-    virtual void Draw()=0;
+public:
+
+    virtual void Draw()
+    {
+        const vulkan::CommandBuffer *cb=cmd_buf[device->GetCurrentFrameIndices()];
+
+        Submit(*cb);
+    }
 
     bool Run()
     {
diff --git a/example/Vulkan/indices_rect.cpp b/example/Vulkan/indices_rect.cpp
index 80789377..599f88a5 100644
--- a/example/Vulkan/indices_rect.cpp
+++ b/example/Vulkan/indices_rect.cpp
@@ -37,15 +37,12 @@ class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
     vulkan::Material *          material            =nullptr;
     vulkan::DescriptorSets *    descriptor_sets     =nullptr;
     vulkan::Renderable *        render_obj          =nullptr;
     vulkan::Buffer *            ubo_mvp             =nullptr;
 
     vulkan::Pipeline *          pipeline            =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
 
     vulkan::VertexBuffer *      vertex_buffer       =nullptr;
     vulkan::IndexBuffer *       index_buffer        =nullptr;
@@ -56,7 +53,6 @@ public:
     {
         SAFE_CLEAR(index_buffer);
         SAFE_CLEAR(vertex_buffer);
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
         SAFE_CLEAR(pipeline);
         SAFE_CLEAR(ubo_mvp);
         SAFE_CLEAR(render_obj);
@@ -122,30 +118,6 @@ private:
         return pipeline;
     }
 
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-                cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-                    cmd_buf[i]->Bind(pipeline);
-                    cmd_buf[i]->Bind(descriptor_sets);
-                    cmd_buf[i]->Bind(render_obj);
-                    cmd_buf[i]->DrawIndexed(INDEX_COUNT);
-                cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
-        return(true);
-    }
-
 public:
 
     bool Init()
@@ -153,8 +125,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
         if(!InitMaterial())
             return(false);
 
@@ -165,21 +135,11 @@ public:
 
         if(!InitPipeline())
             return(false);
-
-        if(!InitCommandBuffer())
-            return(false);
+            
+        BuildCommandBuffer(pipeline,descriptor_sets,render_obj);
 
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 int main(int,char **)
diff --git a/example/Vulkan/main.cpp b/example/Vulkan/main.cpp
index 1c31f1f5..568bdeda 100644
--- a/example/Vulkan/main.cpp
+++ b/example/Vulkan/main.cpp
@@ -38,15 +38,12 @@ class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
     vulkan::Material *          material            =nullptr;
     vulkan::DescriptorSets *    descriptor_sets     =nullptr;
     vulkan::Renderable *        render_obj          =nullptr;
     vulkan::Buffer *            ubo_mvp             =nullptr;
 
     vulkan::Pipeline *          pipeline            =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
 
     vulkan::VertexBuffer *      vertex_buffer       =nullptr;
     vulkan::VertexBuffer *      color_buffer        =nullptr;
@@ -57,7 +54,6 @@ public:
     {
         SAFE_CLEAR(color_buffer);
         SAFE_CLEAR(vertex_buffer);
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
         SAFE_CLEAR(pipeline);
         SAFE_CLEAR(ubo_mvp);
         SAFE_CLEAR(render_obj);
@@ -136,30 +132,6 @@ private:
         return pipeline;
     }
 
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-                cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-                    cmd_buf[i]->Bind(pipeline);
-                    cmd_buf[i]->Bind(descriptor_sets);
-                    cmd_buf[i]->Bind(render_obj);
-                    cmd_buf[i]->Draw(VERTEX_COUNT);
-                cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
-        return(true);
-    }
-
 public:
 
     bool Init()
@@ -167,8 +139,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
         if(!InitMaterial())
             return(false);
 
@@ -180,20 +150,10 @@ public:
         if(!InitPipeline())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
+        BuildCommandBuffer(pipeline,descriptor_sets,render_obj);
 
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 int main(int,char **)
diff --git a/example/Vulkan/texture_rect.cpp b/example/Vulkan/texture_rect.cpp
index 6a491743..c58d54ed 100644
--- a/example/Vulkan/texture_rect.cpp
+++ b/example/Vulkan/texture_rect.cpp
@@ -51,17 +51,14 @@ class TestApp:public VulkanApplicationFramework
 {
 private:
 
-    uint swap_chain_count=0;
-
     vulkan::Material *          material            =nullptr;
     vulkan::Texture2D *         texture             =nullptr;
     vulkan::Sampler *           sampler             =nullptr;
-    vulkan::DescriptorSets *    desciptor_sets      =nullptr;
+    vulkan::DescriptorSets *    descriptor_sets     =nullptr;
     vulkan::Renderable *        render_obj          =nullptr;
     vulkan::Buffer *            ubo_mvp             =nullptr;
 
     vulkan::Pipeline *          pipeline            =nullptr;
-    vulkan::CommandBuffer **    cmd_buf             =nullptr;
 
     vulkan::VertexBuffer *      vertex_buffer       =nullptr;
     vulkan::VertexBuffer *      tex_coord_buffer    =nullptr;
@@ -74,11 +71,10 @@ public:
         SAFE_CLEAR(index_buffer);
         SAFE_CLEAR(tex_coord_buffer);
         SAFE_CLEAR(vertex_buffer);
-        SAFE_CLEAR_OBJECT_ARRAY(cmd_buf,swap_chain_count);
         SAFE_CLEAR(pipeline);
         SAFE_CLEAR(ubo_mvp);
         SAFE_CLEAR(render_obj);
-        SAFE_CLEAR(desciptor_sets);
+        SAFE_CLEAR(descriptor_sets);
         SAFE_CLEAR(sampler);
         SAFE_CLEAR(texture);
         SAFE_CLEAR(material);
@@ -94,7 +90,7 @@ private:
             return(false);
 
         render_obj=material->CreateRenderable(VERTEX_COUNT);
-        desciptor_sets=material->CreateDescriptorSets();
+        descriptor_sets=material->CreateDescriptorSets();
 
         texture=vulkan::LoadTGATexture(OS_TEXT("lena.tga"),device);
 
@@ -113,9 +109,9 @@ private:
 
         sampler=device->CreateSampler(&sampler_create_info);
 
-        desciptor_sets->BindSampler(material->GetSampler("texture_lena"),texture,sampler);
-        desciptor_sets->BindUBO(material->GetUBO("world"),*ubo_mvp);
-        desciptor_sets->Update();
+        descriptor_sets->BindSampler(material->GetSampler("texture_lena"),texture,sampler);
+        descriptor_sets->BindUBO(material->GetUBO("world"),*ubo_mvp);
+        descriptor_sets->Update();
 
         return(true);
     }
@@ -159,30 +155,6 @@ private:
         return pipeline;
     }
 
-    bool InitCommandBuffer()
-    {
-        cmd_buf=hgl_zero_new<vulkan::CommandBuffer *>(swap_chain_count);
-
-        for(uint i=0;i<swap_chain_count;i++)
-        {
-            cmd_buf[i]=device->CreateCommandBuffer();
-
-            if(!cmd_buf[i])
-                return(false);
-
-            cmd_buf[i]->Begin();
-            cmd_buf[i]->BeginRenderPass(device->GetRenderPass(),device->GetFramebuffer(i));
-            cmd_buf[i]->Bind(pipeline);
-            cmd_buf[i]->Bind(desciptor_sets);
-            cmd_buf[i]->Bind(render_obj);
-            cmd_buf[i]->DrawIndexed(INDEX_COUNT);
-            cmd_buf[i]->EndRenderPass();
-            cmd_buf[i]->End();
-        }
-
-        return(true);
-    }
-
 public:
 
     bool Init()
@@ -190,8 +162,6 @@ public:
         if(!VulkanApplicationFramework::Init(SCREEN_WIDTH,SCREEN_HEIGHT))
             return(false);
 
-        swap_chain_count=device->GetSwapChainImageCount();
-
         if(!InitUBO())
             return(false);
 
@@ -203,20 +173,10 @@ public:
         if(!InitPipeline())
             return(false);
 
-        if(!InitCommandBuffer())
-            return(false);
+        BuildCommandBuffer(pipeline,descriptor_sets,render_obj);
 
         return(true);
     }
-
-    void Draw() override
-    {
-        const uint32_t frame_index=device->GetCurrentFrameIndices();
-
-        const vulkan::CommandBuffer *cb=cmd_buf[frame_index];
-
-        Submit(*cb);
-    }
 };//class TestApp:public VulkanApplicationFramework
 
 int main(int,char **)
diff --git a/src/SceneGraph/InlineGeometry.cpp b/src/SceneGraph/InlineGeometry.cpp
index 69427118..84adfa7f 100644
--- a/src/SceneGraph/InlineGeometry.cpp
+++ b/src/SceneGraph/InlineGeometry.cpp
@@ -369,6 +369,7 @@ namespace hgl
             }
 
             render_obj->Set(db->CreateIBO16(6*2*3,indices));
+            db->Add(render_obj);
             return(render_obj);
         }
 
@@ -399,6 +400,7 @@ namespace hgl
                 delete vertex;
             }
 
+            db->Add(render_obj);
             return render_obj;
         }
 
diff --git a/src/SceneGraph/RenderList.cpp b/src/SceneGraph/RenderList.cpp
index 17a33cc5..cfdc1fbc 100644
--- a/src/SceneGraph/RenderList.cpp
+++ b/src/SceneGraph/RenderList.cpp
@@ -86,7 +86,7 @@ namespace hgl
             }
         }
 
-        bool RenderList::Render(vulkan::CommandBuffer *cb)
+        bool RenderList::Render(vulkan::CommandBuffer *cb) 
         {
             if(!cb)
                 return(false);