IECoreUSD::ShaderAlgo : Omit shaderType prefix for some shaders in Rman

Author: danieldresser-ie

Changes

@@ -6,6 +6,11 @@ Fixes
 
 - ConfigLoader : Fixed UnicodeDecodeErrors in non-UTF8 locales.
 
+Breaking Changes
+----------------
+
+- IECoreUSD::ShaderAlgo::writeShaderNetwork : RenderMan specific shaders are now exported to USD without ri: type prefixes, making them compatible with other applications that store shaders in USD for use with RenderMan.
+
 10.6.0.2 (relative to 10.6.0.1)
 ========
 

contrib/IECoreUSD/src/IECoreUSD/ShaderAlgo.cpp

@@ -309,15 +309,33 @@ pxr::UsdShadeConnectableAPI createShaderPrim( const IECoreScene::Shader *shader,
 	{
 		throw IECore::Exception( "Could not create shader at " + path.GetAsString() );
 	}
+
 	const std::string type = shader->getType();
+
 	std::string typePrefix;
-	size_t typeColonPos = type.find( ":" );
-	if( typeColonPos != std::string::npos )
+	if( boost::starts_with( shader->getName(), "Pxr" ) || boost::starts_with( shader->getName(), "Lama" ) )
 	{
-		typePrefix = type.substr( 0, typeColonPos ) + ":";
-		if( typePrefix == "ai:" )
+		// Leave the type prefix empty. This should be the default, but we are currently only doing this
+		// for a small number of shaders that we can be completely confident require it, in order to
+		// preserve backwards compatibility.
+	}
+	else
+	{
+		size_t typeColonPos = type.find( ":" );
+		if( typeColonPos != std::string::npos )
 		{
-			typePrefix = "arnold:";
+			// According to our current understanding, this is almost completely wrong. Renderer's like
+			// PRMan won't accept shaders with type prefixes, and Arnold apparently requires all shaders
+			// to be prefixed with "arnold:", including OSL. This code prefixes OSL shaders with "osl:",
+			// which fails in all renderers we're aware of - we're keeping this behaviour for now for
+			// backwards compatibility reasons.
+			typePrefix = type.substr( 0, typeColonPos ) + ":";
+
+			// This is the one case that actually works
+			if( typePrefix == "ai:" )
+			{
+				typePrefix = "arnold:";
+			}
 		}
 	}
 	usdShader.SetShaderId( pxr::TfToken( typePrefix + shader->getName() ) );

contrib/IECoreUSD/test/IECoreUSD/USDSceneTest.py

@@ -3055,6 +3055,13 @@ def testShaders( self ) :
 		) )
 		manualComponentNetwork.setOutput( IECoreScene.ShaderNetwork.Parameter( "dest", "" ) )
 
+
+		rmanSurface = IECoreScene.Shader( "PxrFoo", "osl:surface", surface.parameters )
+		rmanNetwork = IECoreScene.ShaderNetwork()
+		rmanNetwork.addShader( "out", rmanSurface )
+		rmanNetwork.setOutput( IECoreScene.ShaderNetwork.Parameter( "out", "" ) )
+
+
 		writerRoot = IECoreScene.SceneInterface.create( fileName, IECore.IndexedIO.OpenMode.Write )
 		shaderLocation = writerRoot.createChild( "shaderLocation" )
 		shaderLocation.writeAttribute( "ai:surface", oneShaderNetwork, 0 )
@@ -3063,6 +3070,7 @@ def testShaders( self ) :
 		shaderLocation.writeAttribute( "complex:surface", complexNetwork, 0 )
 		shaderLocation.writeAttribute( "componentConnection:surface", componentConnectionNetwork, 0 )
 		shaderLocation.writeAttribute( "manualComponent:surface", manualComponentNetwork, 0 )
+		shaderLocation.writeAttribute( "ri:surface", rmanNetwork, 0 )
 
 		shaderLocation.writeAttribute( "volume", oneShaderNetwork, 0 ) # USD supports shaders without a prefix
 
@@ -3121,11 +3129,26 @@ def testShaders( self ) :
 		self.assertEqual( textureUsd.GetInput( "filename" ).Get(), "sometexture.tx" )
 
 
+
+
+		riShaderSource = mat.GetOutput( "ri:surface" ).GetConnectedSource()
+		self.assertEqual( riShaderSource[1], "DEFAULT_OUTPUT" )
+		riShaderUsd = pxr.UsdShade.Shader( riShaderSource[0].GetPrim() )
+		self.assertEqual( riShaderUsd.GetShaderId(), "PxrFoo" )
+		self.assertEqual( riShaderUsd.GetInput( "c" ).Get(), "42" )
+		self.assertEqual( riShaderUsd.GetInput( "a" ).Get(), 42.0 )
+		self.assertEqual( riShaderUsd.GetInput( "g" ).Get(), 5 )
+		self.assertEqual( riShaderUsd.GetInput( "g_Knots" ).Get(), pxr.Vt.FloatArray( [0, 0, 10, 20, 20] ) )
+		self.assertEqual( riShaderUsd.GetInput( "g_Colors" ).Get(), pxr.Vt.Vec3fArray(
+			[pxr.Gf.Vec3f( 1 ), pxr.Gf.Vec3f( 1 ), pxr.Gf.Vec3f( 2 ), pxr.Gf.Vec3f( 0 ), pxr.Gf.Vec3f( 0 )]
+		) )
+		self.assertEqual( riShaderUsd.GetInput( "g_Interpolation" ).Get(), 'linear' )
+
 		# Read via SceneInterface, and check that we've round-tripped successfully.
 
 		root = IECoreScene.SceneInterface.create( fileName, IECore.IndexedIO.OpenMode.Read )
 
-		self.assertEqual( set( root.child( "shaderLocation" ).attributeNames() ), set( ['ai:disp_map', 'ai:surface', 'complex:surface', 'volume', 'componentConnection:surface', 'manualComponent:surface' ] ) )
+		self.assertEqual( set( root.child( "shaderLocation" ).attributeNames() ), set( ['ai:disp_map', 'ai:surface', 'complex:surface', 'volume', 'componentConnection:surface', 'manualComponent:surface', "ri:surface" ] ) )
 
 		self.assertEqual( root.child( "shaderLocation" ).readAttribute( "ai:surface", 0 ).outputShader().parameters, oneShaderNetwork.outputShader().parameters )
 		self.assertEqual( root.child( "shaderLocation" ).readAttribute( "ai:surface", 0 ).outputShader(), oneShaderNetwork.outputShader() )
@@ -3150,6 +3173,13 @@ def testShaders( self ) :
 		self.assertEqual( root.child( "shaderLocation" ).readAttribute( "componentConnection:surface", 0 ), componentConnectionNetwork )
 		self.assertEqual( root.child( "shaderLocation" ).readAttribute( "manualComponent:surface", 0 ), manualComponentNetwork )
 
+		rmanSurfaceWithoutTypePrefix = IECoreScene.Shader( "PxrFoo", "surface", surface.parameters )
+		rmanNetworkWithoutTypePrefix = IECoreScene.ShaderNetwork()
+		rmanNetworkWithoutTypePrefix.addShader( "out", rmanSurfaceWithoutTypePrefix )
+		rmanNetworkWithoutTypePrefix.setOutput( IECoreScene.ShaderNetwork.Parameter( "out", "" ) )
+
+		self.assertEqual( root.child( "shaderLocation" ).readAttribute( "ri:surface", 0 ), rmanNetworkWithoutTypePrefix )
+
 	def testManyShaders( self ) :
 
 		# Write shaders