Native instancing isolate select support, with test.

lib/flowViewport/sceneIndex/fvpIsolateSelectSceneIndex.cpp

@@ -23,20 +23,51 @@
 
 #include <pxr/imaging/hd/visibilitySchema.h>
 #include <pxr/imaging/hd/containerDataSourceEditor.h>
+#include <pxr/imaging/hd/instanceSchema.h>
+#include <pxr/imaging/hd/instancerTopologySchema.h>
 
 PXR_NAMESPACE_USING_DIRECTIVE
 
 namespace {
 
+using Dependencies = TfSmallVector<SdfPath, 8>;
+
 const HdContainerDataSourceHandle visOff =
     HdVisibilitySchema::BuildRetained(
         HdRetainedTypedSampledDataSource<bool>::New(false));
 
+const HdDataSourceLocator instancerMaskLocator(
+    HdInstancerTopologySchemaTokens->instancerTopology,
+    HdInstancerTopologySchemaTokens->mask
+);
+
 bool disabled(const Fvp::SelectionConstPtr& a, const Fvp::SelectionConstPtr& b)
 {
     return !a && !b;
 }
 
+void append(Fvp::Selection& a, const Fvp::Selection& b)
+{
+    for (const auto& entry : b) {
+        const auto& primSelections = entry.second;
+        for (const auto& primSelection : primSelections) {
+            a.Add(primSelection);
+        }
+    }
+}
+
+Dependencies instancedPrim(
+    const Fvp::IsolateSelectSceneIndex& si,
+    const SdfPath&                      primPath
+)
+{
+    auto prim = si.GetInputSceneIndex()->GetPrim(primPath);
+    auto instanceSchema = HdInstanceSchema::GetFromParent(prim.dataSource);
+    return (instanceSchema.IsDefined() ? Dependencies{{
+                instanceSchema.GetInstancer()->GetTypedValue(0)}} : 
+        Dependencies());
+}
+
 }
 
 namespace FVP_NS_DEF {
@@ -86,6 +117,17 @@ HdSceneIndexPrim IsolateSelectSceneIndex::GetPrim(const SdfPath& primPath) const
         return inputPrim;
     }
 
+    auto instancerMask = _instancerMasks.find(primPath);
+    if (instancerMask != _instancerMasks.end()) {
+        auto maskDs = HdRetainedTypedSampledDataSource<VtArray<bool>>::New(instancerMask->second);
+
+        inputPrim.dataSource = HdContainerDataSourceEditor(inputPrim.dataSource)
+            .Set(instancerMaskLocator, maskDs)
+            .Finish();
+
+        return inputPrim;
+    }
+
     // If isolate selection is empty, then nothing is included (everything
     // is excluded), as desired.
     const bool included = 
@@ -208,12 +250,12 @@ void IsolateSelectSceneIndex::ReplaceIsolateSelection(const SelectionConstPtr& n
         return;
     }
 
-    _ReplaceIsolateSelection(newIsolateSelection);
+    _DirtyIsolateSelection(newIsolateSelection);
 
     _isolateSelection->Replace(*newIsolateSelection);
 }
 
-void IsolateSelectSceneIndex::_ReplaceIsolateSelection(const SelectionConstPtr& newIsolateSelection)
+void IsolateSelectSceneIndex::_DirtyIsolateSelection(const SelectionConstPtr& newIsolateSelection)
 {
     // Trivial case of going from disabled to disabled is an early out.
     if (disabled(_isolateSelection, newIsolateSelection)) {
@@ -290,9 +332,23 @@ void IsolateSelectSceneIndex::SetViewport(
         return;
     }
 
-    _ReplaceIsolateSelection(newIsolateSelection);
+    // Add dependencies of the new isolate selection to protect them from being
+    // marked as invisible.
+    _AddDependencies(newIsolateSelection);
+
+    _DirtyIsolateSelection(newIsolateSelection);
+
+    // Collect all the instancers from the new isolate selection.
+    auto instancers = _CollectInstancers(newIsolateSelection);
+
+    // Create the instance mask for each instancer.
+    auto newInstancerMasks = _CreateInstancerMasks(instancers, newIsolateSelection);
+
+    // Dirty the instancer masks.
+    _DirtyInstancerMasks(newInstancerMasks);
 
     _isolateSelection = newIsolateSelection;
+    _instancerMasks = newInstancerMasks;
     _viewportId = viewportId;
 }
 
@@ -350,4 +406,136 @@ void IsolateSelectSceneIndex::_DirtyVisibilityRecursive(
     }
 }
 
+void IsolateSelectSceneIndex::_AddDependencies(
+    const SelectionPtr& isolateSelection
+)
+{
+    // Iterate over the input isolate selection, and find the dependencies.
+    // As of 27-Sep-2024 only instancer dependencies are supported.
+    if (!isolateSelection) {
+        return;
+    }
+
+    // Collect dependencies in this selection.
+    Selection dependencies;
+    for (const auto& primSelectionsEntry : *isolateSelection) {
+        for (const auto& primSelection : primSelectionsEntry.second) {
+            auto primDependencies = instancedPrim(*this, primSelection.primPath);
+            for (const auto& dependencyPath : primDependencies) {
+                dependencies.Add(PrimSelection{dependencyPath});
+            }
+        }
+    }
+
+    // Add the collected dependencies to the input isolate selection.
+    append(*isolateSelection, dependencies);
+}
+
+IsolateSelectSceneIndex::Instancers
+IsolateSelectSceneIndex::_CollectInstancers(
+    const SelectionConstPtr& isolateSelection
+) const
+{
+    if (!isolateSelection) {
+        return {};
+    }
+
+    Instancers instancers;
+    for (const auto& primSelectionsEntry : *isolateSelection) {
+        for (const auto& primSelection : primSelectionsEntry.second) {
+            auto prim = GetInputSceneIndex()->GetPrim(primSelection.primPath);
+            auto instanceSchema = HdInstanceSchema::GetFromParent(prim.dataSource);
+            if (instanceSchema.IsDefined()) {
+                instancers.emplace_back(instanceSchema.GetInstancer()->GetTypedValue(0));
+            }
+        }
+    }
+
+    return instancers;
+}
+
+IsolateSelectSceneIndex::InstancerMasks
+IsolateSelectSceneIndex::_CreateInstancerMasks(
+    const Instancers&        instancers,
+    const SelectionConstPtr& isolateSelection
+) const
+{
+    // If isolate select is disabled, no instancer masks to compute.
+    if (!isolateSelection) {
+        return {};
+    }
+
+    // For each instancer, build its mask of visible instances by running all
+    // instances, given by instancerTopology.instanceLocations, through
+    // the isolate selection.  This determines whether the instance is visible
+    // or not.  Store the instancer mask for the instancer path.
+    InstancerMasks instancerMasks;
+    for (const auto& instancerPath : instancers) {
+        HdSceneIndexPrim instancerPrim = GetInputSceneIndex()->GetPrim(instancerPath);
+        HdInstancerTopologySchema instancerTopologySchema = HdInstancerTopologySchema::GetFromParent(instancerPrim.dataSource);
+
+        // Documentation
+        // https://github.com/PixarAnimationStudios/OpenUSD/blob/59992d2178afcebd89273759f2bddfe730e59aa8/pxr/imaging/hd/instancerTopologySchema.h#L86
+        // says that instanceLocations is only meaningful for native
+        // instancing, empty for point instancing.
+        auto instanceLocationsDs = instancerTopologySchema.GetInstanceLocations();
+        if (!instanceLocationsDs) {
+            continue;
+        }
+
+        auto instanceLocations = instanceLocationsDs->GetTypedValue(0.0f);
+
+        VtArray<bool> instanceMask(instanceLocations.size());
+        std::size_t i=0;
+        for (const auto& instanceLocation : instanceLocations) {
+            const bool included = isolateSelection->HasAncestorOrDescendantInclusive(instanceLocation);
+            instanceMask[i] = included;
+            ++i;
+        }
+
+        instancerMasks[instancerPath] = instanceMask;
+    }
+
+    return instancerMasks;
+}
+
+void IsolateSelectSceneIndex::_DirtyInstancerMasks(
+    const InstancerMasks& newInstancerMasks
+)
+{
+    // Keep paths in a set to minimize dirtying.
+    std::set<SdfPath> dirtyPaths;
+
+    // First clear old paths.
+    for (const auto& entry : _instancerMasks) {
+        dirtyPaths.insert(entry.first);
+    }
+
+    // Then add new paths.
+    for (const auto& entry : newInstancerMasks) {
+        dirtyPaths.insert(entry.first);
+    }
+
+    HdSceneIndexObserver::DirtiedPrimEntries dirtiedEntries;
+
+    // Dirty all cleared and added prim paths.
+    for (const auto& primPath : dirtyPaths) {
+        _AddDirtyInstancerMaskEntry(primPath, &dirtiedEntries);
+    }
+
+    _SendPrimsDirtied(dirtiedEntries);
+
+}
+
+void IsolateSelectSceneIndex::_AddDirtyInstancerMaskEntry(
+    const SdfPath&                            primPath, 
+    HdSceneIndexObserver::DirtiedPrimEntries* dirtiedEntries
+) const
+{
+    TF_DEBUG(FVP_ISOLATE_SELECT_SCENE_INDEX)
+        .Msg("            %s: marking %s mask locator dirty.\n", _viewportId.c_str(), primPath.GetText());
+
+    dirtiedEntries->emplace_back(primPath, instancerMaskLocator);
+}
+
 } //end of namespace FVP_NS_DEF

lib/flowViewport/sceneIndex/fvpIsolateSelectSceneIndex.h

@@ -25,6 +25,7 @@
 
 //Hydra headers
 #include <pxr/imaging/hd/filteringSceneIndex.h>
+#include <pxr/base/vt/array.h>
 
 namespace FVP_NS_DEF {
 
@@ -176,16 +177,39 @@ class IsolateSelectSceneIndex :
         PXR_NS::HdSceneIndexObserver::DirtiedPrimEntries* dirtiedEntries
     ) const;
 
-    void _ReplaceIsolateSelection(const SelectionConstPtr& selection);
+    void _DirtyIsolateSelection(const SelectionConstPtr& selection);
 
     void _InsertSelectedPaths(
         const SelectionConstPtr&   selection,
         std::set<PXR_NS::SdfPath>& dirtyPaths
     );
 
+    void _AddDependencies(const SelectionPtr& isolateSelection);
+
+    using Instancers = PXR_NS::TfSmallVector<PXR_NS::SdfPath, 8>;
+    using InstancerMask = PXR_NS::VtArray<bool>;
+    using InstancerMasks = std::map<PXR_NS::SdfPath, InstancerMask>;
+
+    // Collect all the instancers from the argument isolate selection.
+    Instancers _CollectInstancers(
+        const SelectionConstPtr& isolateSelection) const;
+
+    // Create the instance mask for each instancer.
+    InstancerMasks _CreateInstancerMasks(const Instancers& instancers, 
+        const SelectionConstPtr& isolateSelection) const;
+
+    // Dirty the instancer masks.
+    void _DirtyInstancerMasks(const InstancerMasks& instancerMasks);
+    void _AddDirtyInstancerMaskEntry(
+        const PXR_NS::SdfPath&                            primPath, 
+        PXR_NS::HdSceneIndexObserver::DirtiedPrimEntries* dirtiedEntries
+    ) const;    
+
     std::string  _viewportId;
 
     SelectionPtr _isolateSelection{};
+
+    InstancerMasks _instancerMasks{};
 };
 
 }//end of namespace FVP_NS_DEF

lib/flowViewport/sceneIndex/fvpPathInterface.h

@@ -17,6 +17,8 @@
 
 #include "flowViewport/api.h"
 
+#include "flowViewport/selection/fvpSelectionTypes.h"
+
 #include <ufe/ufe.h>
 
 #include <pxr/pxr.h>
@@ -32,37 +34,6 @@ class Path;
 
 namespace FVP_NS_DEF {
 
-// Based on USD's HdInstanceIndicesSchema : 
-// https://github.com/PixarAnimationStudios/OpenUSD/blob/59992d2178afcebd89273759f2bddfe730e59aa8/pxr/imaging/hd/instanceIndicesSchema.h
-struct InstancesSelection {
-    PXR_NS::SdfPath instancerPath;
-    int prototypeIndex;
-    std::vector<int> instanceIndices;
-
-    inline bool operator==(const InstancesSelection &rhs) const {
-        return instancerPath == rhs.instancerPath
-            && prototypeIndex == rhs.prototypeIndex
-            && instanceIndices == rhs.instanceIndices;
-    }
-};
-
-// Based on USD's HdSelectionSchema : 
-// https://github.com/PixarAnimationStudios/OpenUSD/blob/59992d2178afcebd89273759f2bddfe730e59aa8/pxr/imaging/hd/selectionSchema.h
-struct PrimSelection
-{
-    PXR_NS::SdfPath primPath;
-    std::vector<InstancesSelection> nestedInstanceIndices;
-
-    inline bool operator==(const PrimSelection &rhs) const {
-        return primPath == rhs.primPath
-            && nestedInstanceIndices == rhs.nestedInstanceIndices;
-    }
-};
-
-// Using TfSmallVector to optimize for selections that map to a few prims,
-// which is likely going to be the bulk of use cases.
-using PrimSelections = PXR_NS::TfSmallVector<PrimSelection, 8>;
-
 /// \class PathInterface
 ///
 /// A pure interface class to allow for conversion between an application's

lib/flowViewport/selection/CMakeLists.txt

@@ -7,6 +7,7 @@ target_sources(${TARGET_NAME}
     fvpSelectionFwd.cpp
     fvpSelectionTask.cpp
     fvpSelectionTracker.cpp
+    fvpSelectionTypes.cpp
     fvpPathMapper.cpp
     fvpPathMapperFwd.cpp
     fvpPathMapperRegistry.cpp
@@ -19,6 +20,7 @@ set(HEADERS
     fvpSelectionFwd.h
     fvpSelectionTask.h
     fvpSelectionTracker.h
+    fvpSelectionTypes.h
     fvpPathMapper.h
     fvpPathMapperFwd.h
     fvpPathMapperRegistry.h