Previously there was an *overlay* of setting visibility=true for point instancer prototypes. This prevents users from (even temporarily) making their prototypes invisible to remove them from the generated image. Instead, this change moves the data to an *underlay* where explicit visibility authoring will effectively be respected.

This is linked to issue #3748 and also lays a bit more groundwork to address issue #3693

Author: robp-sidefx

pxr/usdImaging/usdImaging/piPrototypeSceneIndex.cpp

@@ -76,21 +76,15 @@ _ComputeUnderlaySource(const SdfPath &instancer, const SdfPath &prototypeRoot)
 }
 
 HdContainerDataSourceHandle
-_ComputePrototypeRootOverlaySource(const SdfPath &instancer)
+_ComputePrototypeRootUnderlaySource(const SdfPath &instancer)
 {
     if (instancer.IsEmpty()) {
         return nullptr;
     }
 
     static HdContainerDataSourceHandle const ds =
         HdRetainedContainerDataSource::New(
-            HdXformSchema::GetSchemaToken(),
-            HdXformSchema::Builder()
-                .SetResetXformStack(
-                    HdRetainedTypedSampledDataSource<bool>::New(
-                        true))
-                .Build(),
-            // We ignore the visibility authored on a prototype instanced
+            // By underlaying this data, we do not override visibility explicitly authored on a prototype instanced
             // by a point instancer in USD.
             HdVisibilitySchema::GetSchemaToken(),
             HdVisibilitySchema::Builder()
@@ -101,6 +95,24 @@ _ComputePrototypeRootOverlaySource(const SdfPath &instancer)
     return ds;
 }
 
+HdContainerDataSourceHandle
+_ComputePrototypeRootOverlaySource(const SdfPath &instancer)
+{
+    if (instancer.IsEmpty()) {
+        return nullptr;
+    }
+
+    static HdContainerDataSourceHandle const ds =
+        HdRetainedContainerDataSource::New(
+            HdXformSchema::GetSchemaToken(),
+            HdXformSchema::Builder()
+                .SetResetXformStack(
+                    HdRetainedTypedSampledDataSource<bool>::New(
+                        true))
+                .Build());
+    return ds;
+}
+
 bool
 _IsOver(const HdSceneIndexPrim &prim)
 {
@@ -132,11 +144,8 @@ UsdImaging_PiPrototypeSceneIndex(
     const SdfPath &instancer,
     const SdfPath &prototypeRoot)
   : HdSingleInputFilteringSceneIndexBase(inputSceneIndex)
+  , _instancer(instancer)
   , _prototypeRoot(prototypeRoot)
-  , _underlaySource(
-      _ComputeUnderlaySource(instancer, prototypeRoot))
-  , _prototypeRootOverlaySource(
-      _ComputePrototypeRootOverlaySource(instancer))
 {
     _Populate();
 }
@@ -211,20 +220,28 @@ UsdImaging_PiPrototypeSceneIndex::GetPrim(const SdfPath &primPath) const
         return prim;
     }
 
-    if (_underlaySource) {
+    TfSmallVector<HdContainerDataSourceHandle, 4> dsVec;
+
+    if (HdContainerDataSourceHandle ds =
+            _ComputePrototypeRootOverlaySource(_instancer);
+            ds && primPath == _prototypeRoot)
+        dsVec.emplace_back(ds);
+    
+    dsVec.emplace_back(prim.dataSource);
+    
+    if (HdContainerDataSourceHandle ds =
+            _ComputePrototypeRootUnderlaySource(_instancer);
+            ds && primPath == _prototypeRoot)
+        dsVec.emplace_back(ds);
+
+    if (HdContainerDataSourceHandle ds =
+            _ComputeUnderlaySource(_instancer, _prototypeRoot))
+        dsVec.emplace_back(ds);
+
+    if (dsVec.size() > 1)
         prim.dataSource = HdOverlayContainerDataSource::New(
-            prim.dataSource,
-            _underlaySource);
-    }
-
-    if (_prototypeRootOverlaySource) {
-        if (primPath == _prototypeRoot) {
-            prim.dataSource = HdOverlayContainerDataSource::New(
-                _prototypeRootOverlaySource,
-                prim.dataSource);
-        }
-    }
-
+            dsVec.size(), dsVec.data());
+    
     return prim;
 }
 

pxr/usdImaging/usdImaging/piPrototypeSceneIndex.h

@@ -148,9 +148,8 @@ class UsdImaging_PiPrototypeSceneIndex final
 
     void _Populate();
 
+    SdfPath _instancer;
     SdfPath _prototypeRoot;
-    HdContainerDataSourceHandle _underlaySource;
-    HdContainerDataSourceHandle _prototypeRootOverlaySource;
 
     // Instancers and overs within the prototype.
     // Note that this does not include instancers or overs nested