Add Hypershade-style Material Editor with node graph and shader-ball preview

Browser column lists all scene materials plus a searchable create-node list; Show Graph (or double-click) loads a material into the node-graph work area. The graph shows the entire network including MaterialX (.mtlx) node graphs, resolving connections through NodeGraph boundaries via UsdShadeUtils::GetValueProducingAttributes, with layered auto-layout for nodes lacking authored uiPosition. Canvas navigates viewport-style (Alt+MMB pan / Alt+RMB zoom) and TAB opens a Nuke-style search popup. Selecting a node shows a typed property editor (live-apply, one undo command per edit) and previews that node's output on the shader ball. The preview renders through its own Hydra engine into a scratch stage that composes the material via a reference to the source root layer (so referenced .mtlx materials work), re-renders until progressive delegates (Arnold/Cycles/Embree) converge, and lights with HDR dome presets (External/Room/Interior/Sunset; CC0 Poly Haven EXRs fetched at CMake configure). texture:format is authored latlong explicitly - left automatic, hdArnold falls back to Arnold's angular fisheye default - and hdCycles gets a -90 X pole rotation to match Storm's +Y-pole sampling. Mutations go through new ICommand subclasses (create shader node, connect/disconnect attrs). imgui-node-editor is vendored (gitignored) with a local one-line patch: c_ScrollButtonIndex 1->2 for MMB pan. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 20:44:54 +08:00
parent 338970b243
commit 09819091c4
20 changed files with 2366 additions and 4 deletions
@@ -0,0 +1,153 @@
+#pragma once
+
+#include "../core/CommandHistory.h"
+#include "../core/MaterialManager.h"
+#include "IconManager.h"
+#include "MaterialPreviewRenderer.h"
+#include <pxr/usd/usd/stage.h>
+#include <pxr/usd/sdf/path.h>
+#include <pxr/usd/sdf/valueTypeName.h>
+#include <pxr/base/vt/value.h>
+#include <imgui_node_editor.h>
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+namespace UsdLayerManager {
+
+/// Node-graph editor for authoring UsdShade material networks, with a
+/// shader-ball preview rendered through Hydra.
+class MaterialEditorPanel {
+public:
+    MaterialEditorPanel();
+    ~MaterialEditorPanel();
+
+    void SetStage(pxr::UsdStageRefPtr stage);
+    void SetMaterialManager(MaterialManager* mgr) { m_materialManager = mgr; }
+    void SetCommandHistory(CommandHistory* history) { m_commandHistory = history; }
+    void SetIconManager(IconManager* icons) { m_iconManager = icons; }
+
+    /// Forwarded to the shader-ball preview so it matches the main viewport's
+    /// global color-correction settings.
+    void SetColorCorrectionFromPrefs(int ccMode, const std::string& ocioDisplay,
+                                     const std::string& ocioView,
+                                     const std::string& ocioColorSpace,
+                                     const std::string& ocioLook);
+
+    /// Opens the material at pathStr in the graph work area, creating it (as a
+    /// "Material" prim) if it doesn't exist yet. Also selects it in the browser.
+    void OpenOrCreateMaterial(const std::string& pathStr);
+
+    /// Tracks the current selection (mirrors PropertyPanel/ViewportPanel's
+    /// SetSelectedPrimPath) so the toolbar can offer "create + bind" / "bind"
+    /// affordances, and so selecting a prim with an already-bound material
+    /// auto-loads it into the canvas.
+    void SetTargetPrimPath(const std::string& path);
+
+    void Render();
+
+private:
+    /// Resolved endpoint of a rendered pin, keyed by its ax::NodeEditor PinId.
+    struct PinInfo {
+        pxr::SdfPath nodePath;
+        std::string  name;
+        bool         isOutput;
+        pxr::SdfValueTypeName typeName;
+    };
+    /// Resolved endpoint of a rendered link, keyed by its ax::NodeEditor LinkId.
+    struct LinkInfo {
+        pxr::SdfPath destNode;
+        std::string  destInput;
+    };
+
+    void RenderToolbar();
+    /// Property editor for the node selected in the graph, shown below the
+    /// shader-ball preview. Values apply live while a widget is being
+    /// dragged; one undoable command is pushed when the edit ends.
+    void RenderSelectedNodeProperties();
+    void RenderInputValueWidget(const ShaderGraphNode& node, const ShaderPinInfo& input,
+                                const pxr::UsdPrim& prim);
+    void CommitInputEdit(const ShaderGraphNode& node, const ShaderPinInfo& input);
+    /// Hypershade-style browser: lists every material on the stage; the
+    /// selected one is loaded into the graph work area via "Show Graph"
+    /// (or double-click).
+    void RenderMaterialBrowser();
+    /// Creates a uniquely-named empty material under /Materials and opens it.
+    void CreateNewMaterial();
+    void RenderNodeGraphCanvas();
+    void RenderPreviewPanel();
+    void HandleCreateAndDelete();
+    /// Nuke-style TAB popup: type-to-filter shader node list; Enter or click
+    /// creates the highlighted node at canvasPos.
+    void RenderNodeSearchMenu(const ImVec2& canvasPos);
+    void CreateShaderNode(const std::string& shaderId, const ImVec2& canvasPos);
+    /// Binds an existing material to targetPath, undoably, restoring whatever
+    /// direct binding (if any) targetPath had before.
+    void BindMaterialToTarget(const pxr::SdfPath& materialPath, const pxr::SdfPath& targetPath);
+    /// Creates a new material named after m_targetPrimPath under /Materials,
+    /// binds it there, and opens it in the canvas.
+    void CreateAndBindMaterialForTarget();
+    void CreateConnection(const PinInfo& destInput, const PinInfo& sourceOutput);
+    void DeleteNode(const pxr::SdfPath& nodePath);
+    void DisconnectAttr(const pxr::SdfPath& destNode, const std::string& destInput);
+    void SyncFromUsd();
+    void PersistNodePosition(ax::NodeEditor::NodeId nodeId);
+    bool IsPinLinked(const pxr::SdfPath& nodePath, const std::string& pinName, bool isOutput) const;
+
+    static bool SaveNodeSettingsCallback(ax::NodeEditor::NodeId nodeId,
+                                         const char* data, size_t size,
+                                         ax::NodeEditor::SaveReasonFlags reason,
+                                         void* userPointer);
+
+    ax::NodeEditor::EditorContext* m_editorContext = nullptr;
+    pxr::UsdStageRefPtr m_stage;
+    MaterialManager*    m_materialManager = nullptr;
+    CommandHistory*     m_commandHistory  = nullptr;
+    IconManager*        m_iconManager     = nullptr;
+
+    /// Material currently shown in the graph work area (empty = none).
+    pxr::SdfPath m_materialPath;
+    /// Material highlighted in the browser list; becomes m_materialPath when
+    /// the user clicks "Show Graph" (or double-clicks the entry).
+    pxr::SdfPath m_browserSelection;
+    /// Currently-selected prim, tracked for the "create + bind" / "bind"
+    /// toolbar affordances; empty when nothing (or a non-prim path) is selected.
+    pxr::SdfPath m_targetPrimPath;
+
+    ShaderGraphSnapshot m_graph;
+    /// NodeId (uintptr_t) -> prim path, for nodes already known to the editor
+    /// this session (seeded position, so re-syncing won't fight live drags).
+    std::unordered_map<uintptr_t, pxr::SdfPath> m_nodeIdToPath;
+    /// Rebuilt every frame from the current m_graph while rendering.
+    std::unordered_map<uintptr_t, PinInfo>  m_pinIdToInfo;
+    std::unordered_map<uintptr_t, LinkInfo> m_linkIdToInfo;
+
+    MaterialPreviewRenderer m_preview;
+
+    ImVec2 m_pendingCreateNodePos{0.0f, 0.0f};
+
+    /// Alt+RMB drag distance not yet converted into a discrete wheel-zoom
+    /// step (the node editor only zooms in wheel increments).
+    float m_zoomDragAccum = 0.0f;
+
+    char m_nodeSearchBuf[128] = "";
+    int  m_nodeSearchSelected = 0;
+
+    /// Search text of the browser's persistent create-node list.
+    char m_browserNodeSearchBuf[128] = "";
+    /// Shader id clicked in the browser's create-node list; created at the
+    /// canvas view center on the next RenderNodeGraphCanvas (ScreenToCanvas
+    /// is only valid inside the editor's Begin/End).
+    std::string m_pendingCreateShaderId;
+
+    /// First node currently selected in the graph editor (empty = none);
+    /// drives the properties section under the preview.
+    pxr::SdfPath m_selectedNodePath;
+    /// Value/authored-state of the input being edited, captured when its
+    /// widget activates, so the commit command can restore it on undo. Only
+    /// one ImGui widget can be active at a time, so one slot suffices.
+    pxr::VtValue m_preEditValue;
+    bool         m_preEditWasAuthored = false;
+};
+
+} // namespace UsdLayerManager