3Delight ShaderNetworkAlgo : Translate UsdPreviewSurface to 3Delight

Changes.md

@@ -18,6 +18,7 @@ Improvements
 - AttributeTweaks, CameraTweaks, ShaderTweaks, OptionTweaks, PrimitiveVariableTweaks :
   - Added support for a `{source}` token which is substituted with the original value when tweaking a string in `Replace` mode.
   - Added tooltips documenting the tweak modes.
+- 3Delight : Added automatic render-time translation of UsdPreviewSurface shaders to 3Delight.
 
 Fixes
 -----

SConstruct

@@ -1315,6 +1315,7 @@ libraries = {
 			],
 		},
 		"pythonEnvAppends" : {
+			"CPPPATH" : [ "$DELIGHT_ROOT/include" ],
 			"LIBS" : [ "IECoreScene$CORTEX_LIB_SUFFIX", "IECoreDelight" ],
 		},
 		"requiredOptions" : [ "DELIGHT_ROOT" ],

include/IECoreDelight/ShaderNetworkAlgo.h

@@ -40,6 +40,8 @@
 
 #include "IECoreScene/ShaderNetwork.h"
 
+#include <nsi.h>
+
 namespace IECoreDelight
 {
 
@@ -54,6 +56,11 @@ const char *lightGeometryType( const IECoreScene::ShaderNetwork *shaderNetwork )
 /// `state` is used to store the current state and avoid unnecessary edits.
 void updateLightGeometry( const IECoreScene::ShaderNetwork *shaderNetwork, NSIContext_t context, const char *handle, IECore::MurmurHash &state );
 
+/// Converts any UsdPreviewSurface shaders and UsdLuxLights into native 3Delight shaders. This conversion
+/// is performed automatically by `preprocessedNetwork()` and is mainly just exposed for the unit
+/// tests.
+IECOREDELIGHT_API void convertUSDShaders( IECoreScene::ShaderNetwork *shaderNetwork );
+
 }  // namespace ShaderNetworkAlgo
 
 }  // namespace IECoreDelight