IECoreUSD::PointInstancerAlgo : Support inactive / invisible ids

Changes

@@ -1,7 +1,9 @@
 10.5.x.x (relative to 10.5.9.2)
 ========
 
-
+Improvements
+------------
+- USDScene : PointInstancers are now loaded with invisibleIds and inactiveIds as primitive variables.
 
 
 10.5.9.2 (relative to 10.5.9.1)

contrib/IECoreUSD/src/IECoreUSD/PointInstancerAlgo.cpp

@@ -86,6 +86,19 @@ IECore::ObjectPtr readPointInstancer( pxr::UsdGeomPointInstancer &pointInstancer
 	Canceller::check( canceller );
 	PrimitiveAlgo::readPrimitiveVariable( pointInstancer.GetAngularVelocitiesAttr(), time, newPoints.get(), "angularVelocity" );
 
+	DataPtr cortexInvisIds = DataAlgo::fromUSD( pointInstancer.GetInvisibleIdsAttr(), time, true );
+	if( cortexInvisIds )
+	{
+		newPoints->variables["invisibleIds"] = IECoreScene::PrimitiveVariable( PrimitiveVariable::Constant, cortexInvisIds );
+	}
+
+	pxr::SdfInt64ListOp inactiveIdsListOp;
+    pointInstancer.GetPrim().GetMetadata( pxr::UsdGeomTokens->inactiveIds, &inactiveIdsListOp );
+	newPoints->variables["inactiveIds"] = IECoreScene::PrimitiveVariable(
+		PrimitiveVariable::Constant,
+		new IECore::Int64VectorData( inactiveIdsListOp.GetExplicitItems() )
+	);
+
 	// Prototype paths
 
 	pxr::SdfPathVector targets;

contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py

@@ -3665,6 +3665,9 @@ def testPointInstancerPrimvars( self ) :
 			[ ( c, c, c ) for c in range( 1, 6 ) ]
 		)
 
+		points.DeactivateIds( [ 0, 2 ] )
+		points.InvisIds( [ 1, 4 ], 0 )
+
 		stage.GetRootLayer().Save()
 
 		# Check we can load the primvar via a SceneInterface.
@@ -3681,6 +3684,9 @@ def testPointInstancerPrimvars( self ) :
 		self.assertEqual( points["myColor"].interpolation, IECoreScene.PrimitiveVariable.Interpolation.Vertex )
 		self.assertEqual( points["myColor"].indices, None )
 
+		self.assertEqual( points["inactiveIds"], IECoreScene.PrimitiveVariable( IECoreScene.PrimitiveVariable.Interpolation.Constant, IECore.Int64VectorData( [ 0, 2 ] ) ) )
+		self.assertEqual( points["invisibleIds"], IECoreScene.PrimitiveVariable( IECoreScene.PrimitiveVariable.Interpolation.Constant, IECore.Int64VectorData( [ 1, 4 ] ) ) )
+
 	def testArnoldArrayInputs( self ) :
 
 		def assertExpectedArrayInputs( network ) :