IECoreUSD : Use / for resolved paths.

On Windows, the result of USD's `GetResolvedPath()` method returns the
resolved path using `\` between directories. This can cause problems
when doing string substition on a resolved path since the `\` will be
interpreted as the start of an escape character. Using `/` also
conforms to Cortex's standard of always using `/` for paths because they
work on all operating systems.

Changes

@@ -1,7 +1,10 @@
 10.5.x.x (relative to 10.5.9.1)
 ========
 
+Fixes
+-----
 
+- IECoreUSD : Asset and volume paths now use `/` in the resolved path on all operating systems.
 
 10.5.9.1 (relative to 10.5.9.0)
 ========

contrib/IECoreUSD/src/IECoreUSD/DataAlgo.cpp

@@ -49,6 +49,8 @@ IECORE_POP_DEFAULT_VISIBILITY
 
 #include "boost/unordered_map.hpp"
 
+#include <filesystem>
+
 using namespace std;
 using namespace pxr;
 using namespace IECore;
@@ -144,7 +146,7 @@ IECore::DataPtr dataFromSdfAssetPath( const SdfAssetPath &assetPath, const pxr::
 {
 	if( assetPath.GetResolvedPath().size() || !assetPath.GetAssetPath().size() || !attribute )
 	{
-		return new StringData( assetPath.GetResolvedPath() );
+		return new StringData( std::filesystem::path( assetPath.GetResolvedPath() ).generic_string() );
 	}
 
 	// Path resolution failed, for a couple of possible reasons :

contrib/IECoreUSD/src/IECoreUSD/VolumeAlgo.cpp

@@ -43,6 +43,8 @@ IECORE_PUSH_DEFAULT_VISIBILITY
 #include "pxr/usd/usdVol/openVDBAsset.h"
 IECORE_POP_DEFAULT_VISIBILITY
 
+#include <filesystem>
+
 using namespace pxr;
 using namespace IECore;
 using namespace IECoreScene;
@@ -98,7 +100,7 @@ IECore::ObjectPtr readVolume( pxr::UsdVolVolume &volume, pxr::UsdTimeCode time,
 
 		SdfAssetPath fieldAssetPath;
 		fieldAsset.GetFilePathAttr().Get( &fieldAssetPath, time );
-		const std::string fieldFileName = fieldAssetPath.GetResolvedPath();
+		const std::string fieldFileName = std::filesystem::path( fieldAssetPath.GetResolvedPath() ).generic_string();
 
 		if( fileName.empty() )
 		{

contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py

@@ -32,6 +32,8 @@
 #
 ##########################################################################
 
+import IECore
+
 import importlib
 import os
 import math
@@ -4257,5 +4259,28 @@ def testPerPurposeModelBound( self ) :
 		self.assertTrue( root.child( "group" ).hasBound() )
 		self.assertEqual( root.child( "group" ).readBound( 0 ), imath.Box3d( imath.V3d( -1 ), imath.V3d( 1 ) ) )
 
+	def testAsetPathSlashes ( self ) :
+
+		root = IECoreScene.SceneInterface.create(
+			os.path.join( os.path.dirname( __file__ ), "data", "assetPathAttribute.usda" ),
+			IECore.IndexedIO.OpenMode.Read
+		)
+		xform = root.child( "xform" )
+
+		self.assertEqual( xform.attributeNames(), [ "render:testAsset" ] )
+		self.assertNotIn( "\\", xform.readAttribute( "render:testAsset", 0 ).value )
+
+	@unittest.skipIf( not haveVDB, "No IECoreVDB" )
+	def testUsdVolVolumeSlashes( self ) :
+
+		import IECoreVDB
+
+		fileName = os.path.dirname( __file__ ) + "/data/volume.usda"
+		root = IECoreScene.SceneInterface.create( fileName, IECore.IndexedIO.OpenMode.Read )
+		child = root.child( "volume" )
+
+		vdbObject = child.readObject( 0 )
+		self.assertNotIn( "\\", vdbObject.fileName() )
+
 if __name__ == "__main__":
 	unittest.main()