Wire viewport shell host chain and move host under app

docs/plan/NewEditor_3D渲染主链正式接入计划_2026-04-12.md

@@ -48,7 +48,7 @@
 
 1. `new_editor/app/Shell/ProductShellAsset.cpp` 里，`scene` 和 `game` 仍然只是 `HostedContent`，还没有切到正式的 `ViewportShell` 主线。
 2. `new_editor/app/Workspace/ProductEditorWorkspace.cpp` 里，没有真正的 viewport service owner，也没有 scene/game render request 生命周期。
-3. `new_editor/Host/NativeRenderer.h/.cpp` 当前是 Direct2D/DirectWrite 宿主，只支持它自己的位图纹理路径。
+3. `new_editor/app/Host/NativeRenderer.h/.cpp` 当前是 Direct2D/DirectWrite 宿主，只支持它自己的位图纹理路径。
 4. `engine/include/XCEngine/UI/Types.h` 虽然已经有 `UITextureHandleKind::ShaderResourceView`，但 `NativeRenderer` 目前并没有真正消费这类引擎 render target。
 
 ### 2.3 根因结论
@@ -132,7 +132,7 @@
 
 主要工作:
 
-1. 在 `new_editor/Host` 下建立正式的 window renderer
+1. 在 `new_editor/app/Host` 下建立正式的 window renderer
 2. 对齐旧 `editor/src/Platform/D3D12WindowRenderer.h` 的能力边界
 3. 让 `Application` 能拿到:
    - `RHIDevice`

new_editor/CMakeLists.txt

@@ -123,13 +123,15 @@ target_link_libraries(XCUIEditorLib PUBLIC
 )
 
 add_library(XCUIEditorHost STATIC
-    Host/AutoScreenshot.cpp
-    Host/NativeRenderer.cpp
+    app/Host/AutoScreenshot.cpp
+    app/Host/D3D12WindowRenderer.cpp
+    app/Host/D3D12WindowRenderLoop.cpp
+    app/Host/NativeRenderer.cpp
 )
 
 target_include_directories(XCUIEditorHost
     PUBLIC
-        ${CMAKE_CURRENT_SOURCE_DIR}
+        ${CMAKE_CURRENT_SOURCE_DIR}/app
         ${CMAKE_CURRENT_SOURCE_DIR}/include
         ${CMAKE_SOURCE_DIR}/engine/include
 )
@@ -139,7 +141,10 @@ xcui_editor_apply_common_target_settings(XCUIEditorHost PUBLIC)
 target_link_libraries(XCUIEditorHost PUBLIC
     XCEngine
     d2d1.lib
+    d3d12.lib
+    d3dcompiler.lib
     dwrite.lib
+    dxgi.lib
     windowscodecs.lib
 )
 
@@ -158,6 +163,8 @@ if(XCENGINE_BUILD_XCUI_EDITOR_APP)
         app/Panels/ProductProjectPanel.cpp
         app/Project/ProductProjectBrowserModel.cpp
         app/Shell/ProductShellAsset.cpp
+        app/Viewport/ProductViewportHostService.cpp
+        app/Viewport/ProductViewportRenderTargets.cpp
         app/Workspace/ProductEditorWorkspace.cpp
         app/Workspace/ProductEditorWorkspaceEventRouter.cpp
     )

new_editor/app/Host/D3D12WindowRenderLoop.cpp

@@ -0,0 +1,63 @@
+#include "D3D12WindowRenderLoop.h"
+
+namespace XCEngine::UI::Editor::Host {
+
+bool RenderD3D12WindowFrame(
+    D3D12WindowRenderer& windowRenderer,
+    const float clearColor[4],
+    const D3D12WindowRenderCallback& beforePresent,
+    const D3D12WindowRenderCallback& afterPresent) {
+    const ::XCEngine::Rendering::RenderSurface* renderSurface =
+        windowRenderer.GetCurrentRenderSurface();
+    ::XCEngine::Rendering::RenderContext renderContext =
+        windowRenderer.GetRenderContext();
+    if (!renderContext.IsValid() ||
+        renderContext.commandList == nullptr ||
+        renderContext.commandQueue == nullptr ||
+        windowRenderer.GetSwapChain() == nullptr ||
+        renderSurface == nullptr) {
+        return false;
+    }
+
+    auto* d3d12CommandList =
+        static_cast<::XCEngine::RHI::D3D12CommandList*>(renderContext.commandList);
+    if (d3d12CommandList == nullptr) {
+        return false;
+    }
+
+    const auto& colorAttachments = renderSurface->GetColorAttachments();
+    if (colorAttachments.empty() || colorAttachments[0] == nullptr) {
+        return false;
+    }
+
+    ::XCEngine::RHI::RHIResourceView* renderTargetView = colorAttachments[0];
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        ::XCEngine::RHI::ResourceStates::Present,
+        ::XCEngine::RHI::ResourceStates::RenderTarget);
+    renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    renderContext.commandList->ClearRenderTarget(renderTargetView, clearColor);
+
+    if (beforePresent) {
+        beforePresent(renderContext, *renderSurface);
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    }
+
+    if (afterPresent) {
+        afterPresent(renderContext, *renderSurface);
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    }
+
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        ::XCEngine::RHI::ResourceStates::RenderTarget,
+        ::XCEngine::RHI::ResourceStates::Present);
+    renderContext.commandList->Close();
+
+    void* commandLists[] = { renderContext.commandList };
+    renderContext.commandQueue->ExecuteCommandLists(1, commandLists);
+    windowRenderer.GetSwapChain()->Present(1, 0);
+    return true;
+}
+
+} // namespace XCEngine::UI::Editor::Host

new_editor/app/Host/D3D12WindowRenderLoop.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "D3D12WindowRenderer.h"
+
+#include <functional>
+
+namespace XCEngine::UI::Editor::Host {
+
+using D3D12WindowRenderCallback =
+    std::function<void(
+        const ::XCEngine::Rendering::RenderContext&,
+        const ::XCEngine::Rendering::RenderSurface&)>;
+
+bool RenderD3D12WindowFrame(
+    D3D12WindowRenderer& windowRenderer,
+    const float clearColor[4],
+    const D3D12WindowRenderCallback& beforePresent = {},
+    const D3D12WindowRenderCallback& afterPresent = {});
+
+} // namespace XCEngine::UI::Editor::Host

new_editor/app/Host/D3D12WindowRenderer.cpp

@@ -0,0 +1,400 @@
+#include "D3D12WindowRenderer.h"
+
+#include <XCEngine/RHI/RHIFactory.h>
+
+namespace XCEngine::UI::Editor::Host {
+
+using ::XCEngine::RHI::CommandListDesc;
+using ::XCEngine::RHI::CommandQueueDesc;
+using ::XCEngine::RHI::DescriptorHeapType;
+using ::XCEngine::RHI::DescriptorPoolDesc;
+using ::XCEngine::RHI::D3D12CommandList;
+using ::XCEngine::RHI::D3D12CommandQueue;
+using ::XCEngine::RHI::D3D12DescriptorHeap;
+using ::XCEngine::RHI::D3D12Device;
+using ::XCEngine::RHI::D3D12SwapChain;
+using ::XCEngine::RHI::D3D12Texture;
+using ::XCEngine::RHI::Format;
+using ::XCEngine::RHI::ResourceStates;
+using ::XCEngine::RHI::ResourceViewDesc;
+using ::XCEngine::RHI::ResourceViewDimension;
+using ::XCEngine::RHI::RHICommandList;
+using ::XCEngine::RHI::RHICommandQueue;
+using ::XCEngine::RHI::RHIDevice;
+using ::XCEngine::RHI::RHIDeviceDesc;
+using ::XCEngine::RHI::RHIFactory;
+using ::XCEngine::RHI::RHISwapChain;
+using ::XCEngine::RHI::RHIType;
+using ::XCEngine::RHI::SwapChainDesc;
+
+bool D3D12WindowRenderer::Initialize(HWND hwnd, int width, int height) {
+    Shutdown();
+
+    if (hwnd == nullptr || width <= 0 || height <= 0) {
+        return false;
+    }
+
+    m_hwnd = hwnd;
+    m_width = width;
+    m_height = height;
+
+    m_device = RHIFactory::CreateRHIDevice(RHIType::D3D12);
+    if (m_device == nullptr) {
+        Shutdown();
+        return false;
+    }
+
+    RHIDeviceDesc deviceDesc = {};
+#ifdef _DEBUG
+    deviceDesc.enableDebugLayer = true;
+    deviceDesc.enableGPUValidation = true;
+#endif
+    if (!m_device->Initialize(deviceDesc)) {
+        Shutdown();
+        return false;
+    }
+
+    CommandQueueDesc queueDesc = {};
+    queueDesc.queueType = static_cast<std::uint32_t>(::XCEngine::RHI::CommandQueueType::Direct);
+    m_commandQueue = m_device->CreateCommandQueue(queueDesc);
+    if (m_commandQueue == nullptr || GetD3D12CommandQueue() == nullptr) {
+        Shutdown();
+        return false;
+    }
+
+    CommandListDesc commandListDesc = {};
+    commandListDesc.commandListType = static_cast<std::uint32_t>(::XCEngine::RHI::CommandQueueType::Direct);
+    m_commandList = m_device->CreateCommandList(commandListDesc);
+    if (m_commandList == nullptr || GetD3D12CommandList() == nullptr) {
+        Shutdown();
+        return false;
+    }
+    m_commandList->Close();
+
+    SwapChainDesc swapChainDesc = {};
+    swapChainDesc.windowHandle = hwnd;
+    swapChainDesc.width = static_cast<std::uint32_t>(width);
+    swapChainDesc.height = static_cast<std::uint32_t>(height);
+    swapChainDesc.bufferCount = kSwapChainBufferCount;
+    m_swapChain = m_device->CreateSwapChain(swapChainDesc, m_commandQueue);
+    if (m_swapChain == nullptr || GetD3D12SwapChain() == nullptr) {
+        Shutdown();
+        return false;
+    }
+
+    DescriptorPoolDesc srvPoolDesc = {};
+    srvPoolDesc.type = DescriptorHeapType::CBV_SRV_UAV;
+    srvPoolDesc.descriptorCount = kSrvDescriptorCount;
+    srvPoolDesc.shaderVisible = true;
+    m_srvPool = m_device->CreateDescriptorPool(srvPoolDesc);
+    m_srvHeap = dynamic_cast<D3D12DescriptorHeap*>(m_srvPool);
+    if (m_srvPool == nullptr || m_srvHeap == nullptr) {
+        Shutdown();
+        return false;
+    }
+
+    m_srvDescriptorSize = m_srvHeap->GetDescriptorSize();
+    m_srvUsage.assign(kSrvDescriptorCount, false);
+    if (!RecreateBackBufferViews()) {
+        Shutdown();
+        return false;
+    }
+
+    return true;
+}
+
+void D3D12WindowRenderer::Shutdown() {
+    WaitForGpuIdle();
+    ReleaseBackBufferViews();
+
+    if (m_srvPool != nullptr) {
+        m_srvPool->Shutdown();
+        delete m_srvPool;
+        m_srvPool = nullptr;
+    }
+    m_srvHeap = nullptr;
+    m_srvUsage.clear();
+
+    if (m_swapChain != nullptr) {
+        m_swapChain->Shutdown();
+        delete m_swapChain;
+        m_swapChain = nullptr;
+    }
+
+    if (m_commandList != nullptr) {
+        m_commandList->Shutdown();
+        delete m_commandList;
+        m_commandList = nullptr;
+    }
+
+    if (m_commandQueue != nullptr) {
+        m_commandQueue->Shutdown();
+        delete m_commandQueue;
+        m_commandQueue = nullptr;
+    }
+
+    if (m_device != nullptr) {
+        m_device->Shutdown();
+        delete m_device;
+        m_device = nullptr;
+    }
+
+    m_hwnd = nullptr;
+    m_width = 0;
+    m_height = 0;
+    m_srvDescriptorSize = 0;
+}
+
+void D3D12WindowRenderer::Resize(int width, int height) {
+    if (width <= 0 || height <= 0 || m_swapChain == nullptr) {
+        return;
+    }
+
+    WaitForGpuIdle();
+    ReleaseBackBufferViews();
+
+    m_swapChain->Resize(static_cast<std::uint32_t>(width), static_cast<std::uint32_t>(height));
+    m_width = width;
+    m_height = height;
+    RecreateBackBufferViews();
+}
+
+bool D3D12WindowRenderer::BeginFrame() {
+    D3D12CommandQueue* d3d12Queue = GetD3D12CommandQueue();
+    D3D12CommandList* d3d12CommandList = GetD3D12CommandList();
+    if (m_swapChain == nullptr ||
+        d3d12Queue == nullptr ||
+        d3d12CommandList == nullptr ||
+        m_srvHeap == nullptr) {
+        return false;
+    }
+
+    d3d12Queue->WaitForPreviousFrame();
+    m_commandList->Reset();
+    return true;
+}
+
+ID3D12Device* D3D12WindowRenderer::GetDevice() const {
+    const D3D12Device* device = GetD3D12Device();
+    return device != nullptr ? device->GetDevice() : nullptr;
+}
+
+ID3D12DescriptorHeap* D3D12WindowRenderer::GetSrvHeap() const {
+    return m_srvHeap != nullptr ? m_srvHeap->GetDescriptorHeap() : nullptr;
+}
+
+ID3D12CommandQueue* D3D12WindowRenderer::GetCommandQueue() const {
+    const D3D12CommandQueue* queue = GetD3D12CommandQueue();
+    return queue != nullptr ? queue->GetCommandQueue() : nullptr;
+}
+
+void D3D12WindowRenderer::AllocateShaderResourceDescriptor(
+    D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+    D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle) {
+    AllocateShaderResourceDescriptorInternal(outCpuHandle, outGpuHandle);
+}
+
+bool D3D12WindowRenderer::CreateShaderResourceTextureDescriptor(
+    RHIDevice* device,
+    ::XCEngine::RHI::RHITexture* texture,
+    D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+    D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle) {
+    if (device == nullptr ||
+        texture == nullptr ||
+        outCpuHandle == nullptr ||
+        outGpuHandle == nullptr) {
+        return false;
+    }
+
+    *outCpuHandle = {};
+    *outGpuHandle = {};
+
+    auto* nativeDevice = dynamic_cast<D3D12Device*>(device);
+    auto* nativeTexture = dynamic_cast<D3D12Texture*>(texture);
+    if (nativeDevice == nullptr ||
+        nativeTexture == nullptr ||
+        nativeTexture->GetResource() == nullptr) {
+        return false;
+    }
+
+    AllocateShaderResourceDescriptorInternal(outCpuHandle, outGpuHandle);
+    if (outCpuHandle->ptr == 0 || outGpuHandle->ptr == 0) {
+        *outCpuHandle = {};
+        *outGpuHandle = {};
+        return false;
+    }
+
+    D3D12_SHADER_RESOURCE_VIEW_DESC srvDesc = {};
+    srvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
+    srvDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    srvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
+    srvDesc.Texture2D.MipLevels = 1;
+    nativeDevice->GetDevice()->CreateShaderResourceView(
+        nativeTexture->GetResource(),
+        &srvDesc,
+        *outCpuHandle);
+    return true;
+}
+
+void D3D12WindowRenderer::FreeShaderResourceDescriptor(
+    D3D12_CPU_DESCRIPTOR_HANDLE cpuHandle,
+    D3D12_GPU_DESCRIPTOR_HANDLE gpuHandle) {
+    FreeShaderResourceDescriptorInternal(cpuHandle, gpuHandle);
+}
+
+UINT D3D12WindowRenderer::GetSrvDescriptorSize() const {
+    return m_srvDescriptorSize;
+}
+
+UINT D3D12WindowRenderer::GetSrvDescriptorCount() const {
+    return kSrvDescriptorCount;
+}
+
+RHIDevice* D3D12WindowRenderer::GetRHIDevice() const {
+    return m_device;
+}
+
+RHISwapChain* D3D12WindowRenderer::GetSwapChain() const {
+    return m_swapChain;
+}
+
+const ::XCEngine::Rendering::RenderSurface* D3D12WindowRenderer::GetCurrentRenderSurface() const {
+    if (m_swapChain == nullptr) {
+        return nullptr;
+    }
+
+    const std::uint32_t backBufferIndex = m_swapChain->GetCurrentBackBufferIndex();
+    if (backBufferIndex >= m_backBufferSurfaces.size()) {
+        return nullptr;
+    }
+
+    return &m_backBufferSurfaces[backBufferIndex];
+}
+
+::XCEngine::Rendering::RenderContext D3D12WindowRenderer::GetRenderContext() const {
+    ::XCEngine::Rendering::RenderContext context = {};
+    context.device = m_device;
+    context.commandList = m_commandList;
+    context.commandQueue = m_commandQueue;
+    context.backendType = RHIType::D3D12;
+    return context;
+}
+
+D3D12Device* D3D12WindowRenderer::GetD3D12Device() const {
+    return m_device != nullptr ? static_cast<D3D12Device*>(m_device) : nullptr;
+}
+
+D3D12CommandQueue* D3D12WindowRenderer::GetD3D12CommandQueue() const {
+    return m_commandQueue != nullptr ? static_cast<D3D12CommandQueue*>(m_commandQueue) : nullptr;
+}
+
+D3D12CommandList* D3D12WindowRenderer::GetD3D12CommandList() const {
+    return m_commandList != nullptr ? static_cast<D3D12CommandList*>(m_commandList) : nullptr;
+}
+
+D3D12SwapChain* D3D12WindowRenderer::GetD3D12SwapChain() const {
+    return m_swapChain != nullptr ? static_cast<D3D12SwapChain*>(m_swapChain) : nullptr;
+}
+
+void D3D12WindowRenderer::AllocateShaderResourceDescriptorInternal(
+    D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+    D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle) {
+    if (outCpuHandle == nullptr || outGpuHandle == nullptr) {
+        return;
+    }
+
+    *outCpuHandle = {};
+    *outGpuHandle = {};
+    if (m_srvHeap == nullptr ||
+        m_srvDescriptorSize == 0 ||
+        m_srvUsage.empty()) {
+        return;
+    }
+
+    for (std::size_t index = 0; index < m_srvUsage.size(); ++index) {
+        if (m_srvUsage[index]) {
+            continue;
+        }
+
+        m_srvUsage[index] = true;
+        outCpuHandle->ptr =
+            m_srvHeap->GetCPUDescriptorHandleForHeapStart().ptr +
+            static_cast<SIZE_T>(index) * m_srvDescriptorSize;
+        outGpuHandle->ptr =
+            m_srvHeap->GetGPUDescriptorHandleForHeapStart().ptr +
+            static_cast<UINT64>(index) * m_srvDescriptorSize;
+        return;
+    }
+}
+
+void D3D12WindowRenderer::FreeShaderResourceDescriptorInternal(
+    D3D12_CPU_DESCRIPTOR_HANDLE cpuHandle,
+    D3D12_GPU_DESCRIPTOR_HANDLE) {
+    if (m_srvHeap == nullptr ||
+        m_srvDescriptorSize == 0 ||
+        cpuHandle.ptr < m_srvHeap->GetCPUDescriptorHandleForHeapStart().ptr) {
+        return;
+    }
+
+    const SIZE_T offset =
+        cpuHandle.ptr - m_srvHeap->GetCPUDescriptorHandleForHeapStart().ptr;
+    const std::size_t index =
+        static_cast<std::size_t>(offset / m_srvDescriptorSize);
+    if (index < m_srvUsage.size()) {
+        m_srvUsage[index] = false;
+    }
+}
+
+void D3D12WindowRenderer::WaitForGpuIdle() {
+    if (m_commandQueue != nullptr) {
+        m_commandQueue->WaitForIdle();
+    }
+}
+
+void D3D12WindowRenderer::ReleaseBackBufferViews() {
+    for (auto* view : m_backBufferViews) {
+        if (view != nullptr) {
+            view->Shutdown();
+            delete view;
+        }
+    }
+    m_backBufferViews.clear();
+    m_backBufferSurfaces.clear();
+}
+
+bool D3D12WindowRenderer::RecreateBackBufferViews() {
+    D3D12SwapChain* d3d12SwapChain = GetD3D12SwapChain();
+    if (m_device == nullptr || d3d12SwapChain == nullptr) {
+        return false;
+    }
+
+    m_backBufferViews.resize(kSwapChainBufferCount, nullptr);
+    m_backBufferSurfaces.resize(kSwapChainBufferCount);
+
+    ResourceViewDesc viewDesc = {};
+    viewDesc.format = static_cast<std::uint32_t>(Format::R8G8B8A8_UNorm);
+    viewDesc.dimension = ResourceViewDimension::Texture2D;
+
+    for (std::uint32_t backBufferIndex = 0; backBufferIndex < kSwapChainBufferCount; ++backBufferIndex) {
+        m_backBufferViews[backBufferIndex] = m_device->CreateRenderTargetView(
+            &d3d12SwapChain->GetBackBuffer(backBufferIndex),
+            viewDesc);
+        if (m_backBufferViews[backBufferIndex] == nullptr) {
+            ReleaseBackBufferViews();
+            return false;
+        }
+
+        ::XCEngine::Rendering::RenderSurface& surface = m_backBufferSurfaces[backBufferIndex];
+        surface = ::XCEngine::Rendering::RenderSurface(
+            static_cast<std::uint32_t>(m_width),
+            static_cast<std::uint32_t>(m_height));
+        surface.SetColorAttachment(m_backBufferViews[backBufferIndex]);
+        surface.SetAutoTransitionEnabled(false);
+        surface.SetColorStateBefore(ResourceStates::RenderTarget);
+        surface.SetColorStateAfter(ResourceStates::RenderTarget);
+    }
+
+    return true;
+}
+
+} // namespace XCEngine::UI::Editor::Host

new_editor/app/Host/D3D12WindowRenderer.h

@@ -0,0 +1,92 @@
+#pragma once
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+
+#include <XCEngine/Rendering/RenderContext.h>
+#include <XCEngine/Rendering/RenderSurface.h>
+#include <XCEngine/RHI/D3D12/D3D12CommandList.h>
+#include <XCEngine/RHI/D3D12/D3D12CommandQueue.h>
+#include <XCEngine/RHI/D3D12/D3D12DescriptorHeap.h>
+#include <XCEngine/RHI/D3D12/D3D12Device.h>
+#include <XCEngine/RHI/D3D12/D3D12SwapChain.h>
+#include <XCEngine/RHI/D3D12/D3D12Texture.h>
+#include <XCEngine/RHI/RHICommandList.h>
+#include <XCEngine/RHI/RHICommandQueue.h>
+#include <XCEngine/RHI/RHIDescriptorPool.h>
+#include <XCEngine/RHI/RHIDevice.h>
+#include <XCEngine/RHI/RHIResourceView.h>
+#include <XCEngine/RHI/RHITexture.h>
+#include <XCEngine/RHI/RHISwapChain.h>
+
+#include <d3d12.h>
+#include <windows.h>
+
+#include <vector>
+
+namespace XCEngine::UI::Editor::Host {
+
+class D3D12WindowRenderer {
+public:
+    static constexpr UINT kSrvDescriptorCount = 64;
+    static constexpr std::uint32_t kSwapChainBufferCount = 3;
+
+    bool Initialize(HWND hwnd, int width, int height);
+    void Shutdown();
+    void Resize(int width, int height);
+    bool BeginFrame();
+
+    ID3D12Device* GetDevice() const;
+    ID3D12DescriptorHeap* GetSrvHeap() const;
+    ID3D12CommandQueue* GetCommandQueue() const;
+    void AllocateShaderResourceDescriptor(
+        D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle);
+    bool CreateShaderResourceTextureDescriptor(
+        ::XCEngine::RHI::RHIDevice* device,
+        ::XCEngine::RHI::RHITexture* texture,
+        D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle);
+    void FreeShaderResourceDescriptor(
+        D3D12_CPU_DESCRIPTOR_HANDLE cpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE gpuHandle);
+    UINT GetSrvDescriptorSize() const;
+    UINT GetSrvDescriptorCount() const;
+    ::XCEngine::RHI::RHIDevice* GetRHIDevice() const;
+    ::XCEngine::RHI::RHISwapChain* GetSwapChain() const;
+    const ::XCEngine::Rendering::RenderSurface* GetCurrentRenderSurface() const;
+    ::XCEngine::Rendering::RenderContext GetRenderContext() const;
+
+private:
+    ::XCEngine::RHI::D3D12Device* GetD3D12Device() const;
+    ::XCEngine::RHI::D3D12CommandQueue* GetD3D12CommandQueue() const;
+    ::XCEngine::RHI::D3D12CommandList* GetD3D12CommandList() const;
+    ::XCEngine::RHI::D3D12SwapChain* GetD3D12SwapChain() const;
+    void AllocateShaderResourceDescriptorInternal(
+        D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle);
+    void FreeShaderResourceDescriptorInternal(
+        D3D12_CPU_DESCRIPTOR_HANDLE cpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE gpuHandle);
+    void WaitForGpuIdle();
+    void ReleaseBackBufferViews();
+    bool RecreateBackBufferViews();
+
+    HWND m_hwnd = nullptr;
+    int m_width = 0;
+    int m_height = 0;
+
+    ::XCEngine::RHI::RHIDevice* m_device = nullptr;
+    ::XCEngine::RHI::RHICommandQueue* m_commandQueue = nullptr;
+    ::XCEngine::RHI::RHICommandList* m_commandList = nullptr;
+    ::XCEngine::RHI::RHISwapChain* m_swapChain = nullptr;
+    ::XCEngine::RHI::RHIDescriptorPool* m_srvPool = nullptr;
+    ::XCEngine::RHI::D3D12DescriptorHeap* m_srvHeap = nullptr;
+    std::vector<bool> m_srvUsage = {};
+    std::vector<::XCEngine::RHI::RHIResourceView*> m_backBufferViews = {};
+    std::vector<::XCEngine::Rendering::RenderSurface> m_backBufferSurfaces = {};
+    UINT m_srvDescriptorSize = 0;
+};
+
+} // namespace XCEngine::UI::Editor::Host

new_editor/app/Shell/ProductShellAsset.cpp

@@ -21,8 +21,8 @@ UIEditorPanelRegistry BuildPanelRegistry() {
     UIEditorPanelRegistry registry = {};
     registry.panels = {
         { "hierarchy", "Hierarchy", UIEditorPanelPresentationKind::HostedContent, true, false, false },
-        { "scene", "Scene", UIEditorPanelPresentationKind::HostedContent, false, false, false },
-        { "game", "Game", UIEditorPanelPresentationKind::HostedContent, false, false, false },
+        { "scene", "Scene", UIEditorPanelPresentationKind::ViewportShell, false, false, false },
+        { "game", "Game", UIEditorPanelPresentationKind::ViewportShell, false, false, false },
         { "inspector", "Inspector", UIEditorPanelPresentationKind::HostedContent, true, false, false },
         { "console", "Console", UIEditorPanelPresentationKind::HostedContent, true, false, false },
         { "project", "Project", UIEditorPanelPresentationKind::HostedContent, false, false, false }
@@ -421,6 +421,22 @@ UIEditorWorkspacePanelPresentationModel BuildHostedContentPresentation(
     return presentation;
 }
 
+UIEditorWorkspacePanelPresentationModel BuildViewportPresentation(
+    std::string panelId,
+    std::string title,
+    std::string subtitle) {
+    UIEditorWorkspacePanelPresentationModel presentation = {};
+    presentation.panelId = std::move(panelId);
+    presentation.kind = UIEditorPanelPresentationKind::ViewportShell;
+    presentation.viewportShellModel.spec.chrome.title = std::move(title);
+    presentation.viewportShellModel.spec.chrome.subtitle = std::move(subtitle);
+    presentation.viewportShellModel.spec.chrome.showTopBar = true;
+    presentation.viewportShellModel.spec.chrome.showBottomBar = true;
+    presentation.viewportShellModel.frame.statusText =
+        "Viewport request chain is active.";
+    return presentation;
+}
+
 UIEditorShellInteractionDefinition BuildBaseShellDefinition() {
     UIEditorShellInteractionDefinition definition = {};
     definition.menuModel = BuildMenuModel();
@@ -432,8 +448,8 @@ UIEditorShellInteractionDefinition BuildBaseShellDefinition() {
     definition.statusSegments = {};
     definition.workspacePresentations = {
         BuildHostedContentPresentation("hierarchy"),
-        BuildHostedContentPresentation("scene"),
-        BuildHostedContentPresentation("game"),
+        BuildViewportPresentation("scene", "Scene", "New Editor viewport shell"),
+        BuildViewportPresentation("game", "Game", "New Editor viewport shell"),
         BuildHostedContentPresentation("inspector"),
         BuildHostedContentPresentation("console"),
         BuildHostedContentPresentation("project")

new_editor/app/Viewport/ProductViewportHostService.cpp

@@ -0,0 +1,225 @@
+#include "ProductViewportHostService.h"
+
+#include <XCEngine/RHI/RHICommandList.h>
+
+namespace XCEngine::UI::Editor::App {
+
+namespace {
+
+using ::XCEngine::RHI::ResourceStates;
+
+std::string BuildViewportPendingStatus(ProductViewportKind kind) {
+    return kind == ProductViewportKind::Scene
+        ? "Scene viewport host pending D3D12 presenter integration."
+        : "Game viewport host pending D3D12 presenter integration.";
+}
+
+std::string BuildViewportReadyStatus(ProductViewportKind kind) {
+    return kind == ProductViewportKind::Scene
+        ? "Scene viewport render target ready; presenter still uses NativeRenderer."
+        : "Game viewport render target ready; presenter still uses NativeRenderer.";
+}
+
+std::string BuildViewportPresentedStatus(ProductViewportKind kind) {
+    return kind == ProductViewportKind::Scene
+        ? "Scene viewport frame ready."
+        : "Game viewport frame ready.";
+}
+
+} // namespace
+
+void ProductViewportHostService::AttachWindowRenderer(
+    Host::D3D12WindowRenderer& windowRenderer) {
+    if (m_windowRenderer == &windowRenderer) {
+        m_device = windowRenderer.GetRHIDevice();
+        return;
+    }
+
+    Shutdown();
+    m_windowRenderer = &windowRenderer;
+    m_device = windowRenderer.GetRHIDevice();
+}
+
+void ProductViewportHostService::DetachWindowRenderer() {
+    Shutdown();
+}
+
+void ProductViewportHostService::SetSurfacePresentationEnabled(bool enabled) {
+    m_surfacePresentationEnabled = enabled;
+}
+
+void ProductViewportHostService::Shutdown() {
+    for (ViewportEntry& entry : m_entries) {
+        DestroyViewportEntry(entry);
+    }
+
+    m_windowRenderer = nullptr;
+    m_device = nullptr;
+    m_surfacePresentationEnabled = false;
+}
+
+void ProductViewportHostService::BeginFrame() {
+    for (ViewportEntry& entry : m_entries) {
+        entry.requestedWidth = 0;
+        entry.requestedHeight = 0;
+        entry.requestedThisFrame = false;
+        entry.renderedThisFrame = false;
+        entry.kind = (&entry == &m_entries[0]) ? ProductViewportKind::Scene : ProductViewportKind::Game;
+    }
+}
+
+ProductViewportFrame ProductViewportHostService::RequestViewport(
+    ProductViewportKind kind,
+    const ::XCEngine::UI::UISize& requestedSize) {
+    ViewportEntry& entry = GetEntry(kind);
+    entry.requestedThisFrame = requestedSize.width > 1.0f && requestedSize.height > 1.0f;
+    entry.requestedWidth = entry.requestedThisFrame
+        ? static_cast<std::uint32_t>(requestedSize.width)
+        : 0u;
+    entry.requestedHeight = entry.requestedThisFrame
+        ? static_cast<std::uint32_t>(requestedSize.height)
+        : 0u;
+
+    if (!entry.requestedThisFrame) {
+        entry.statusText = "Viewport is waiting for a visible surface.";
+        return BuildFrame(entry, requestedSize);
+    }
+
+    if (m_windowRenderer == nullptr || m_device == nullptr) {
+        entry.statusText = BuildViewportPendingStatus(kind);
+        return BuildFrame(entry, requestedSize);
+    }
+
+    if (!EnsureViewportResources(entry)) {
+        entry.statusText = "Failed to create viewport render targets.";
+        return BuildFrame(entry, requestedSize);
+    }
+
+    entry.statusText = m_surfacePresentationEnabled
+        ? BuildViewportPresentedStatus(kind)
+        : BuildViewportReadyStatus(kind);
+    return BuildFrame(entry, requestedSize);
+}
+
+void ProductViewportHostService::RenderRequestedViewports(
+    const ::XCEngine::Rendering::RenderContext& renderContext) {
+    if (m_windowRenderer == nullptr || m_device == nullptr || !renderContext.IsValid()) {
+        return;
+    }
+
+    for (ViewportEntry& entry : m_entries) {
+        if (!entry.requestedThisFrame || !EnsureViewportResources(entry)) {
+            continue;
+        }
+
+        if (entry.kind == ProductViewportKind::Scene) {
+            ClearViewport(entry, renderContext, 0.16f, 0.17f, 0.19f, 1.0f);
+        } else {
+            ClearViewport(entry, renderContext, 0.11f, 0.11f, 0.12f, 1.0f);
+        }
+
+        entry.renderedThisFrame = true;
+        entry.statusText = m_surfacePresentationEnabled
+            ? BuildViewportPresentedStatus(entry.kind)
+            : BuildViewportReadyStatus(entry.kind);
+    }
+}
+
+ProductViewportHostService::ViewportEntry& ProductViewportHostService::GetEntry(
+    ProductViewportKind kind) {
+    const std::size_t index = kind == ProductViewportKind::Scene ? 0u : 1u;
+    ViewportEntry& entry = m_entries[index];
+    entry.kind = kind;
+    return entry;
+}
+
+const ProductViewportHostService::ViewportEntry& ProductViewportHostService::GetEntry(
+    ProductViewportKind kind) const {
+    const std::size_t index = kind == ProductViewportKind::Scene ? 0u : 1u;
+    return m_entries[index];
+}
+
+void ProductViewportHostService::DestroyViewportEntry(ViewportEntry& entry) {
+    DestroyProductViewportRenderTargets(m_windowRenderer, entry.renderTargets);
+    entry = {};
+}
+
+bool ProductViewportHostService::EnsureViewportResources(ViewportEntry& entry) {
+    const ProductViewportResourceReuseQuery reuseQuery =
+        BuildProductViewportRenderTargetsReuseQuery(
+            entry.kind,
+            entry.renderTargets,
+            entry.requestedWidth,
+            entry.requestedHeight);
+    if (CanReuseProductViewportResources(reuseQuery)) {
+        return true;
+    }
+
+    if (m_windowRenderer == nullptr ||
+        m_device == nullptr ||
+        entry.requestedWidth == 0u ||
+        entry.requestedHeight == 0u) {
+        return false;
+    }
+
+    return CreateProductViewportRenderTargets(
+        entry.kind,
+        entry.requestedWidth,
+        entry.requestedHeight,
+        m_device,
+        *m_windowRenderer,
+        entry.renderTargets);
+}
+
+void ProductViewportHostService::ClearViewport(
+    ViewportEntry& entry,
+    const ::XCEngine::Rendering::RenderContext& renderContext,
+    float r,
+    float g,
+    float b,
+    float a) {
+    if (renderContext.commandList == nullptr ||
+        entry.renderTargets.colorView == nullptr ||
+        entry.renderTargets.depthView == nullptr) {
+        return;
+    }
+
+    auto* commandList = renderContext.commandList;
+    auto* colorView = entry.renderTargets.colorView;
+    const float clearColor[4] = { r, g, b, a };
+    commandList->TransitionBarrier(
+        colorView,
+        entry.renderTargets.colorState,
+        ResourceStates::RenderTarget);
+    commandList->SetRenderTargets(1, &colorView, entry.renderTargets.depthView);
+    commandList->ClearRenderTarget(colorView, clearColor);
+    commandList->ClearDepthStencil(entry.renderTargets.depthView, 1.0f, 0);
+    commandList->TransitionBarrier(
+        colorView,
+        ResourceStates::RenderTarget,
+        ResourceStates::PixelShaderResource);
+    entry.renderTargets.colorState = ResourceStates::PixelShaderResource;
+    entry.renderTargets.hasValidObjectIdFrame = false;
+}
+
+ProductViewportFrame ProductViewportHostService::BuildFrame(
+    const ViewportEntry& entry,
+    const ::XCEngine::UI::UISize& requestedSize) const {
+    ProductViewportFrame frame = {};
+    frame.requestedSize = requestedSize;
+    frame.renderSize = ::XCEngine::UI::UISize(
+        static_cast<float>(entry.renderTargets.width),
+        static_cast<float>(entry.renderTargets.height));
+    frame.wasRequested = entry.requestedThisFrame;
+    frame.statusText = entry.statusText;
+
+    if (m_surfacePresentationEnabled &&
+        entry.renderTargets.textureHandle.IsValid()) {
+        frame.texture = entry.renderTargets.textureHandle;
+        frame.hasTexture = true;
+    }
+
+    return frame;
+}
+
+} // namespace XCEngine::UI::Editor::App

new_editor/app/Viewport/ProductViewportHostService.h

@@ -0,0 +1,64 @@
+#pragma once
+
+#include "ProductViewportRenderTargets.h"
+
+#include <Host/D3D12WindowRenderer.h>
+
+#include <XCEngine/Rendering/RenderContext.h>
+#include <XCEngine/UI/Types.h>
+
+#include <array>
+#include <cstdint>
+#include <string>
+
+namespace XCEngine::UI::Editor::App {
+
+class ProductViewportHostService {
+public:
+    void AttachWindowRenderer(Host::D3D12WindowRenderer& windowRenderer);
+    void DetachWindowRenderer();
+    void SetSurfacePresentationEnabled(bool enabled);
+
+    void Shutdown();
+    void BeginFrame();
+
+    ProductViewportFrame RequestViewport(
+        ProductViewportKind kind,
+        const ::XCEngine::UI::UISize& requestedSize);
+
+    void RenderRequestedViewports(
+        const ::XCEngine::Rendering::RenderContext& renderContext);
+
+private:
+    struct ViewportEntry {
+        ProductViewportKind kind = ProductViewportKind::Scene;
+        std::uint32_t requestedWidth = 0;
+        std::uint32_t requestedHeight = 0;
+        bool requestedThisFrame = false;
+        bool renderedThisFrame = false;
+        ProductViewportRenderTargets renderTargets = {};
+        std::string statusText = {};
+    };
+
+    ViewportEntry& GetEntry(ProductViewportKind kind);
+    const ViewportEntry& GetEntry(ProductViewportKind kind) const;
+    void DestroyViewportEntry(ViewportEntry& entry);
+    bool EnsureViewportResources(ViewportEntry& entry);
+    void ClearViewport(
+        ViewportEntry& entry,
+        const ::XCEngine::Rendering::RenderContext& renderContext,
+        float r,
+        float g,
+        float b,
+        float a);
+    ProductViewportFrame BuildFrame(
+        const ViewportEntry& entry,
+        const ::XCEngine::UI::UISize& requestedSize) const;
+
+    Host::D3D12WindowRenderer* m_windowRenderer = nullptr;
+    ::XCEngine::RHI::RHIDevice* m_device = nullptr;
+    bool m_surfacePresentationEnabled = false;
+    std::array<ViewportEntry, 2> m_entries = {};
+};
+
+} // namespace XCEngine::UI::Editor::App

new_editor/app/Viewport/ProductViewportRenderTargets.cpp

@@ -0,0 +1 @@
+#include "ProductViewportRenderTargets.h"

new_editor/app/Viewport/ProductViewportRenderTargets.h

@@ -0,0 +1,301 @@
+#pragma once
+
+#include "ProductViewportSurfaceUtils.h"
+
+#include <Host/D3D12WindowRenderer.h>
+
+#include <XCEngine/RHI/RHIDevice.h>
+#include <XCEngine/RHI/RHIResourceView.h>
+#include <XCEngine/RHI/RHITexture.h>
+#include <XCEngine/UI/Types.h>
+
+namespace XCEngine::UI::Editor::App {
+
+struct ProductViewportRenderTargets {
+    std::uint32_t width = 0;
+    std::uint32_t height = 0;
+    ::XCEngine::RHI::RHITexture* colorTexture = nullptr;
+    ::XCEngine::RHI::RHIResourceView* colorView = nullptr;
+    ::XCEngine::RHI::RHITexture* depthTexture = nullptr;
+    ::XCEngine::RHI::RHIResourceView* depthView = nullptr;
+    ::XCEngine::RHI::RHIResourceView* depthShaderView = nullptr;
+    ::XCEngine::RHI::RHITexture* objectIdTexture = nullptr;
+    ::XCEngine::RHI::RHITexture* objectIdDepthTexture = nullptr;
+    ::XCEngine::RHI::RHIResourceView* objectIdDepthView = nullptr;
+    ::XCEngine::RHI::RHIResourceView* objectIdView = nullptr;
+    ::XCEngine::RHI::RHIResourceView* objectIdShaderView = nullptr;
+    ::XCEngine::RHI::RHITexture* selectionMaskTexture = nullptr;
+    ::XCEngine::RHI::RHIResourceView* selectionMaskView = nullptr;
+    ::XCEngine::RHI::RHIResourceView* selectionMaskShaderView = nullptr;
+    D3D12_CPU_DESCRIPTOR_HANDLE srvCpuHandle = {};
+    D3D12_GPU_DESCRIPTOR_HANDLE srvGpuHandle = {};
+    ::XCEngine::UI::UITextureHandle textureHandle = {};
+    ::XCEngine::RHI::ResourceStates colorState = ::XCEngine::RHI::ResourceStates::Common;
+    ::XCEngine::RHI::ResourceStates objectIdState = ::XCEngine::RHI::ResourceStates::Common;
+    ::XCEngine::RHI::ResourceStates selectionMaskState = ::XCEngine::RHI::ResourceStates::Common;
+    bool hasValidObjectIdFrame = false;
+};
+
+inline ProductViewportResourceReuseQuery BuildProductViewportRenderTargetsReuseQuery(
+    ProductViewportKind kind,
+    const ProductViewportRenderTargets& targets,
+    std::uint32_t requestedWidth,
+    std::uint32_t requestedHeight) {
+    ProductViewportResourceReuseQuery query = {};
+    query.kind = kind;
+    query.width = targets.width;
+    query.height = targets.height;
+    query.requestedWidth = requestedWidth;
+    query.requestedHeight = requestedHeight;
+    query.resources.hasColorTexture = targets.colorTexture != nullptr;
+    query.resources.hasColorView = targets.colorView != nullptr;
+    query.resources.hasDepthTexture = targets.depthTexture != nullptr;
+    query.resources.hasDepthView = targets.depthView != nullptr;
+    query.resources.hasDepthShaderView = targets.depthShaderView != nullptr;
+    query.resources.hasObjectIdTexture = targets.objectIdTexture != nullptr;
+    query.resources.hasObjectIdDepthTexture = targets.objectIdDepthTexture != nullptr;
+    query.resources.hasObjectIdDepthView = targets.objectIdDepthView != nullptr;
+    query.resources.hasObjectIdView = targets.objectIdView != nullptr;
+    query.resources.hasObjectIdShaderView = targets.objectIdShaderView != nullptr;
+    query.resources.hasSelectionMaskTexture = targets.selectionMaskTexture != nullptr;
+    query.resources.hasSelectionMaskView = targets.selectionMaskView != nullptr;
+    query.resources.hasSelectionMaskShaderView = targets.selectionMaskShaderView != nullptr;
+    query.resources.hasTextureDescriptor = targets.textureHandle.IsValid();
+    return query;
+}
+
+inline ::XCEngine::Rendering::RenderSurface BuildProductViewportColorSurface(
+    const ProductViewportRenderTargets& targets) {
+    return BuildProductViewportRenderSurface(
+        targets.width,
+        targets.height,
+        targets.colorView,
+        targets.depthView,
+        targets.colorState);
+}
+
+inline ::XCEngine::Rendering::RenderSurface BuildProductViewportObjectIdSurface(
+    const ProductViewportRenderTargets& targets) {
+    return BuildProductViewportRenderSurface(
+        targets.width,
+        targets.height,
+        targets.objectIdView,
+        targets.objectIdDepthView,
+        targets.objectIdState);
+}
+
+inline ::XCEngine::Rendering::RenderSurface BuildProductViewportSelectionMaskSurface(
+    const ProductViewportRenderTargets& targets) {
+    return BuildProductViewportRenderSurface(
+        targets.width,
+        targets.height,
+        targets.selectionMaskView,
+        targets.depthView,
+        targets.selectionMaskState);
+}
+
+namespace Internal {
+
+template <typename ResourceType>
+inline void ShutdownAndDeleteViewportResource(ResourceType*& resource) {
+    if (resource == nullptr) {
+        return;
+    }
+
+    resource->Shutdown();
+    delete resource;
+    resource = nullptr;
+}
+
+inline bool CreateViewportColorResources(
+    ::XCEngine::RHI::RHIDevice* device,
+    ProductViewportRenderTargets& targets) {
+    const auto colorDesc =
+        BuildProductViewportTextureDesc(targets.width, targets.height, ::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.colorTexture = device->CreateTexture(colorDesc);
+    if (targets.colorTexture == nullptr) {
+        return false;
+    }
+
+    const auto colorViewDesc =
+        BuildProductViewportTextureViewDesc(::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.colorView = device->CreateRenderTargetView(targets.colorTexture, colorViewDesc);
+    return targets.colorView != nullptr;
+}
+
+inline bool CreateViewportDepthResources(
+    ::XCEngine::RHI::RHIDevice* device,
+    ProductViewportRenderTargets& targets) {
+    const auto depthDesc =
+        BuildProductViewportTextureDesc(targets.width, targets.height, ::XCEngine::RHI::Format::D24_UNorm_S8_UInt);
+    targets.depthTexture = device->CreateTexture(depthDesc);
+    if (targets.depthTexture == nullptr) {
+        return false;
+    }
+
+    const auto depthViewDesc =
+        BuildProductViewportTextureViewDesc(::XCEngine::RHI::Format::D24_UNorm_S8_UInt);
+    targets.depthView = device->CreateDepthStencilView(targets.depthTexture, depthViewDesc);
+    if (targets.depthView == nullptr) {
+        return false;
+    }
+
+    ::XCEngine::RHI::ResourceViewDesc depthShaderViewDesc = {};
+    depthShaderViewDesc.dimension = ::XCEngine::RHI::ResourceViewDimension::Texture2D;
+    depthShaderViewDesc.mipLevel = 0;
+    targets.depthShaderView = device->CreateShaderResourceView(
+        targets.depthTexture,
+        depthShaderViewDesc);
+    return targets.depthShaderView != nullptr;
+}
+
+inline bool CreateViewportObjectIdResources(
+    ::XCEngine::RHI::RHIDevice* device,
+    ProductViewportRenderTargets& targets) {
+    const auto objectIdDesc =
+        BuildProductViewportTextureDesc(targets.width, targets.height, ::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.objectIdTexture = device->CreateTexture(objectIdDesc);
+    if (targets.objectIdTexture == nullptr) {
+        return false;
+    }
+
+    const auto objectIdViewDesc =
+        BuildProductViewportTextureViewDesc(::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.objectIdView = device->CreateRenderTargetView(targets.objectIdTexture, objectIdViewDesc);
+    if (targets.objectIdView == nullptr) {
+        return false;
+    }
+
+    targets.objectIdShaderView = device->CreateShaderResourceView(
+        targets.objectIdTexture,
+        objectIdViewDesc);
+    if (targets.objectIdShaderView == nullptr) {
+        return false;
+    }
+
+    const auto objectIdDepthDesc =
+        BuildProductViewportTextureDesc(targets.width, targets.height, ::XCEngine::RHI::Format::D24_UNorm_S8_UInt);
+    targets.objectIdDepthTexture = device->CreateTexture(objectIdDepthDesc);
+    if (targets.objectIdDepthTexture == nullptr) {
+        return false;
+    }
+
+    const auto objectIdDepthViewDesc =
+        BuildProductViewportTextureViewDesc(::XCEngine::RHI::Format::D24_UNorm_S8_UInt);
+    targets.objectIdDepthView = device->CreateDepthStencilView(
+        targets.objectIdDepthTexture,
+        objectIdDepthViewDesc);
+    return targets.objectIdDepthView != nullptr;
+}
+
+inline bool CreateViewportSelectionMaskResources(
+    ::XCEngine::RHI::RHIDevice* device,
+    ProductViewportRenderTargets& targets) {
+    const auto selectionMaskDesc =
+        BuildProductViewportTextureDesc(targets.width, targets.height, ::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.selectionMaskTexture = device->CreateTexture(selectionMaskDesc);
+    if (targets.selectionMaskTexture == nullptr) {
+        return false;
+    }
+
+    const auto selectionMaskViewDesc =
+        BuildProductViewportTextureViewDesc(::XCEngine::RHI::Format::R8G8B8A8_UNorm);
+    targets.selectionMaskView = device->CreateRenderTargetView(
+        targets.selectionMaskTexture,
+        selectionMaskViewDesc);
+    if (targets.selectionMaskView == nullptr) {
+        return false;
+    }
+
+    targets.selectionMaskShaderView = device->CreateShaderResourceView(
+        targets.selectionMaskTexture,
+        selectionMaskViewDesc);
+    return targets.selectionMaskShaderView != nullptr;
+}
+
+inline bool CreateViewportTextureDescriptor(
+    Host::D3D12WindowRenderer& windowRenderer,
+    ::XCEngine::RHI::RHIDevice* device,
+    ProductViewportRenderTargets& targets) {
+    if (!windowRenderer.CreateShaderResourceTextureDescriptor(
+            device,
+            targets.colorTexture,
+            &targets.srvCpuHandle,
+            &targets.srvGpuHandle)) {
+        return false;
+    }
+
+    targets.textureHandle.nativeHandle = static_cast<std::uintptr_t>(targets.srvGpuHandle.ptr);
+    targets.textureHandle.width = targets.width;
+    targets.textureHandle.height = targets.height;
+    targets.textureHandle.kind = ::XCEngine::UI::UITextureHandleKind::ShaderResourceView;
+    return true;
+}
+
+} // namespace Internal
+
+inline void DestroyProductViewportRenderTargets(
+    Host::D3D12WindowRenderer* windowRenderer,
+    ProductViewportRenderTargets& targets) {
+    if (windowRenderer != nullptr && targets.srvCpuHandle.ptr != 0) {
+        windowRenderer->FreeShaderResourceDescriptor(targets.srvCpuHandle, targets.srvGpuHandle);
+    }
+
+    Internal::ShutdownAndDeleteViewportResource(targets.objectIdView);
+    Internal::ShutdownAndDeleteViewportResource(targets.objectIdShaderView);
+    Internal::ShutdownAndDeleteViewportResource(targets.objectIdDepthView);
+    Internal::ShutdownAndDeleteViewportResource(targets.objectIdDepthTexture);
+    Internal::ShutdownAndDeleteViewportResource(targets.objectIdTexture);
+    Internal::ShutdownAndDeleteViewportResource(targets.selectionMaskView);
+    Internal::ShutdownAndDeleteViewportResource(targets.selectionMaskShaderView);
+    Internal::ShutdownAndDeleteViewportResource(targets.selectionMaskTexture);
+    Internal::ShutdownAndDeleteViewportResource(targets.depthShaderView);
+    Internal::ShutdownAndDeleteViewportResource(targets.depthView);
+    Internal::ShutdownAndDeleteViewportResource(targets.depthTexture);
+    Internal::ShutdownAndDeleteViewportResource(targets.colorView);
+    Internal::ShutdownAndDeleteViewportResource(targets.colorTexture);
+
+    targets.width = 0;
+    targets.height = 0;
+    targets.srvCpuHandle = {};
+    targets.srvGpuHandle = {};
+    targets.textureHandle = {};
+    targets.colorState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.objectIdState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.selectionMaskState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.hasValidObjectIdFrame = false;
+}
+
+inline bool CreateProductViewportRenderTargets(
+    ProductViewportKind kind,
+    std::uint32_t width,
+    std::uint32_t height,
+    ::XCEngine::RHI::RHIDevice* device,
+    Host::D3D12WindowRenderer& windowRenderer,
+    ProductViewportRenderTargets& targets) {
+    if (width == 0u || height == 0u || device == nullptr) {
+        return false;
+    }
+
+    DestroyProductViewportRenderTargets(&windowRenderer, targets);
+    targets.width = width;
+    targets.height = height;
+
+    if (!Internal::CreateViewportColorResources(device, targets) ||
+        !Internal::CreateViewportDepthResources(device, targets) ||
+        (ProductViewportRequiresObjectIdResources(kind) &&
+         (!Internal::CreateViewportObjectIdResources(device, targets) ||
+          !Internal::CreateViewportSelectionMaskResources(device, targets))) ||
+        !Internal::CreateViewportTextureDescriptor(windowRenderer, device, targets)) {
+        DestroyProductViewportRenderTargets(&windowRenderer, targets);
+        return false;
+    }
+
+    targets.colorState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.objectIdState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.selectionMaskState = ::XCEngine::RHI::ResourceStates::Common;
+    targets.hasValidObjectIdFrame = false;
+    return true;
+}
+
+} // namespace XCEngine::UI::Editor::App

new_editor/app/Viewport/ProductViewportSurfaceUtils.h

@@ -0,0 +1,130 @@
+#pragma once
+
+#include "ProductViewportTypes.h"
+
+#include <XCEngine/RHI/RHIEnums.h>
+#include <XCEngine/RHI/RHIResourceView.h>
+#include <XCEngine/RHI/RHITypes.h>
+#include <XCEngine/Rendering/RenderSurface.h>
+
+#include <algorithm>
+#include <cmath>
+#include <cstdint>
+
+namespace XCEngine::UI::Editor::App {
+
+struct ProductViewportResourcePresence {
+    bool hasColorTexture = false;
+    bool hasColorView = false;
+    bool hasDepthTexture = false;
+    bool hasDepthView = false;
+    bool hasDepthShaderView = false;
+    bool hasObjectIdTexture = false;
+    bool hasObjectIdDepthTexture = false;
+    bool hasObjectIdDepthView = false;
+    bool hasObjectIdView = false;
+    bool hasObjectIdShaderView = false;
+    bool hasSelectionMaskTexture = false;
+    bool hasSelectionMaskView = false;
+    bool hasSelectionMaskShaderView = false;
+    bool hasTextureDescriptor = false;
+};
+
+struct ProductViewportResourceReuseQuery {
+    ProductViewportKind kind = ProductViewportKind::Scene;
+    std::uint32_t width = 0;
+    std::uint32_t height = 0;
+    std::uint32_t requestedWidth = 0;
+    std::uint32_t requestedHeight = 0;
+    ProductViewportResourcePresence resources = {};
+};
+
+inline bool ProductViewportRequiresObjectIdResources(ProductViewportKind kind) {
+    return kind == ProductViewportKind::Scene;
+}
+
+inline std::uint32_t ClampViewportPixelCoordinate(float value, std::uint32_t extent) {
+    if (extent == 0u) {
+        return 0u;
+    }
+
+    const float maxCoordinate = static_cast<float>(extent - 1u);
+    const float clamped = (std::max)(0.0f, (std::min)(value, maxCoordinate));
+    return static_cast<std::uint32_t>(std::floor(clamped));
+}
+
+inline bool CanReuseProductViewportResources(const ProductViewportResourceReuseQuery& query) {
+    if (query.requestedWidth == 0u || query.requestedHeight == 0u) {
+        return false;
+    }
+
+    if (query.width != query.requestedWidth || query.height != query.requestedHeight) {
+        return false;
+    }
+
+    if (!query.resources.hasColorTexture ||
+        !query.resources.hasColorView ||
+        !query.resources.hasDepthTexture ||
+        !query.resources.hasDepthView ||
+        !query.resources.hasTextureDescriptor) {
+        return false;
+    }
+
+    if (!ProductViewportRequiresObjectIdResources(query.kind)) {
+        return true;
+    }
+
+    return query.resources.hasObjectIdTexture &&
+        query.resources.hasObjectIdDepthTexture &&
+        query.resources.hasObjectIdDepthView &&
+        query.resources.hasObjectIdView &&
+        query.resources.hasObjectIdShaderView &&
+        query.resources.hasDepthShaderView &&
+        query.resources.hasSelectionMaskTexture &&
+        query.resources.hasSelectionMaskView &&
+        query.resources.hasSelectionMaskShaderView;
+}
+
+inline ::XCEngine::RHI::TextureDesc BuildProductViewportTextureDesc(
+    std::uint32_t width,
+    std::uint32_t height,
+    ::XCEngine::RHI::Format format) {
+    ::XCEngine::RHI::TextureDesc desc = {};
+    desc.width = width;
+    desc.height = height;
+    desc.depth = 1;
+    desc.mipLevels = 1;
+    desc.arraySize = 1;
+    desc.format = static_cast<std::uint32_t>(format);
+    desc.textureType = static_cast<std::uint32_t>(::XCEngine::RHI::TextureType::Texture2D);
+    desc.sampleCount = 1;
+    desc.sampleQuality = 0;
+    desc.flags = 0;
+    return desc;
+}
+
+inline ::XCEngine::RHI::ResourceViewDesc BuildProductViewportTextureViewDesc(
+    ::XCEngine::RHI::Format format) {
+    ::XCEngine::RHI::ResourceViewDesc desc = {};
+    desc.format = static_cast<std::uint32_t>(format);
+    desc.dimension = ::XCEngine::RHI::ResourceViewDimension::Texture2D;
+    return desc;
+}
+
+inline ::XCEngine::Rendering::RenderSurface BuildProductViewportRenderSurface(
+    std::uint32_t width,
+    std::uint32_t height,
+    ::XCEngine::RHI::RHIResourceView* colorView,
+    ::XCEngine::RHI::RHIResourceView* depthView,
+    ::XCEngine::RHI::ResourceStates colorStateBefore,
+    ::XCEngine::RHI::ResourceStates colorStateAfter =
+        ::XCEngine::RHI::ResourceStates::PixelShaderResource) {
+    ::XCEngine::Rendering::RenderSurface surface(width, height);
+    surface.SetColorAttachment(colorView);
+    surface.SetDepthAttachment(depthView);
+    surface.SetColorStateBefore(colorStateBefore);
+    surface.SetColorStateAfter(colorStateAfter);
+    return surface;
+}
+
+} // namespace XCEngine::UI::Editor::App

new_editor/app/Viewport/ProductViewportTypes.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <XCEngine/UI/Types.h>
+
+#include <cstdint>
+#include <string>
+
+namespace XCEngine::UI::Editor::App {
+
+enum class ProductViewportKind : std::uint8_t {
+    Scene = 0,
+    Game
+};
+
+struct ProductViewportFrame {
+    ::XCEngine::UI::UITextureHandle texture = {};
+    ::XCEngine::UI::UISize requestedSize = {};
+    ::XCEngine::UI::UISize renderSize = {};
+    bool hasTexture = false;
+    bool wasRequested = false;
+    std::string statusText = {};
+};
+
+} // namespace XCEngine::UI::Editor::App

new_editor/app/Workspace/ProductEditorWorkspace.cpp

@@ -16,6 +16,55 @@ using ::XCEngine::UI::UIDrawList;
 using ::XCEngine::UI::UIInputEvent;
 using ::XCEngine::UI::UIInputEventType;
 
+bool IsProductViewportPanel(std::string_view panelId) {
+    return panelId == "scene" || panelId == "game";
+}
+
+ProductViewportKind ResolveProductViewportKind(std::string_view panelId) {
+    return panelId == "game"
+        ? ProductViewportKind::Game
+        : ProductViewportKind::Scene;
+}
+
+void ApplyViewportFrameToPresentation(
+    const ProductViewportFrame& viewportFrame,
+    UIEditorWorkspacePanelPresentationModel& presentation) {
+    presentation.viewportShellModel.frame.texture = viewportFrame.texture;
+    presentation.viewportShellModel.frame.requestedSize = viewportFrame.requestedSize;
+    presentation.viewportShellModel.frame.presentedSize = viewportFrame.renderSize;
+    presentation.viewportShellModel.frame.hasTexture = viewportFrame.hasTexture;
+    presentation.viewportShellModel.frame.statusText = viewportFrame.statusText;
+}
+
+std::vector<UIEditorWorkspacePanelPresentationModel> BuildWorkspacePresentations(
+    const UIEditorShellInteractionDefinition& definition,
+    const UIEditorShellInteractionRequest& shellRequest,
+    ProductViewportHostService& viewportHostService) {
+    std::vector<UIEditorWorkspacePanelPresentationModel> presentations =
+        definition.workspacePresentations;
+    for (UIEditorWorkspacePanelPresentationModel& presentation : presentations) {
+        if (presentation.kind != UIEditorPanelPresentationKind::ViewportShell ||
+            !IsProductViewportPanel(presentation.panelId)) {
+            continue;
+        }
+
+        const UIEditorWorkspaceViewportComposeRequest* viewportRequest =
+            FindUIEditorWorkspaceViewportPresentationRequest(
+                shellRequest.shellRequest.workspaceRequest,
+                presentation.panelId);
+        const ::XCEngine::UI::UISize requestedSize =
+            viewportRequest != nullptr
+                ? viewportRequest->viewportShellRequest.requestedViewportSize
+                : ::XCEngine::UI::UISize();
+        ApplyViewportFrameToPresentation(
+            viewportHostService.RequestViewport(
+                ResolveProductViewportKind(presentation.panelId),
+                requestedSize),
+            presentation);
+    }
+    return presentations;
+}
+
 UIEditorShellComposeModel BuildShellComposeModelFromFrame(
     const UIEditorShellInteractionFrame& frame) {
     UIEditorShellComposeModel model = {};
@@ -93,6 +142,7 @@ void ProductEditorWorkspace::Shutdown() {
     m_shellFrame = {};
     m_shellInteractionState = {};
     m_traceEntries.clear();
+    m_viewportHostService.Shutdown();
     m_builtInIcons.Shutdown();
 }
 
@@ -103,8 +153,21 @@ void ProductEditorWorkspace::Update(
     std::string_view captureText) {
     const auto& metrics = ResolveUIEditorShellInteractionMetrics();
     context.SyncSessionFromWorkspace();
-    const UIEditorShellInteractionDefinition definition =
+    UIEditorShellInteractionDefinition definition =
         context.BuildShellDefinition(captureText);
+    m_viewportHostService.BeginFrame();
+    const UIEditorShellInteractionRequest shellRequest =
+        ResolveUIEditorShellInteractionRequest(
+            bounds,
+            context.GetWorkspaceController(),
+            definition,
+            m_shellInteractionState,
+            metrics,
+            context.GetShellServices());
+    definition.workspacePresentations = BuildWorkspacePresentations(
+        definition,
+        shellRequest,
+        m_viewportHostService);
     const std::vector<UIInputEvent> hostedContentEvents = inputEvents;
     const std::vector<UIInputEvent> shellEvents =
         HasHostedContentCapture()

new_editor/app/Workspace/ProductEditorWorkspace.h

@@ -6,6 +6,7 @@
 #include "Panels/ProductHierarchyPanel.h"
 #include "Panels/ProductInspectorPanel.h"
 #include "Panels/ProductProjectPanel.h"
+#include "Viewport/ProductViewportHostService.h"
 #include "Workspace/ProductEditorWorkspaceEventRouter.h"
 
 #include <Host/NativeRenderer.h>
@@ -50,6 +51,7 @@ public:
     bool HasInteractiveCapture() const;
 
 private:
+    ProductViewportHostService m_viewportHostService = {};
     ProductBuiltInIcons m_builtInIcons = {};
     ProductConsolePanel m_consolePanel = {};
     ProductHierarchyPanel m_hierarchyPanel = {};

tests/UI/Editor/CMakeLists.txt

@@ -5,14 +5,16 @@ project(XCEngine_EditorUITests)
 set(XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT
     "${CMAKE_SOURCE_DIR}/new_editor")
 
-if(NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/Host/AutoScreenshot.h"
-    OR NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/Host/InputModifierTracker.h"
-    OR NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/Host/NativeRenderer.h")
+if(NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/app/Host/AutoScreenshot.h"
+    OR NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/app/Host/InputModifierTracker.h"
+    OR NOT EXISTS "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/app/Host/NativeRenderer.h")
     message(FATAL_ERROR
         "Editor UI tests expect host headers under "
-        "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/Host.")
+        "${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/app/Host.")
 endif()
 
+include_directories("${XCENGINE_EDITOR_UI_TESTS_EDITOR_ROOT}/app")
+
 add_subdirectory(unit)
 add_subdirectory(integration)