Fix build failure when WITH_USD=OFF and WITH_MATERIALX=ON

source/blender/nodes/shader/CMakeLists.txt

@@ -139,10 +139,6 @@ set(LIB
 
 if(WITH_MATERIALX)
   add_definitions(-DWITH_MATERIALX)
-  list(APPEND INC
-    ${USD_INCLUDE_DIRS}
-    ${BOOST_INCLUDE_DIR}
-  )
   list(APPEND SRC
     materialx/material.cc
     materialx/node_item.cc
@@ -158,6 +154,14 @@ if(WITH_MATERIALX)
     MaterialXCore
     MaterialXFormat
   )
+
+  if(WITH_USD)
+    add_definitions(-DWITH_USD)
+    list(APPEND INC_SYS
+      ${USD_INCLUDE_DIRS}
+      ${BOOST_INCLUDE_DIR}
+    )
+  endif()
 endif()
 
 if(WITH_FREESTYLE)

source/blender/nodes/shader/materialx/node_parser.cc

@@ -2,7 +2,9 @@
  *
  * SPDX-License-Identifier: GPL-2.0-or-later */
 
-#include <pxr/base/tf/stringUtils.h>
+#ifdef WITH_USD
+#  include <pxr/base/tf/stringUtils.h>
+#endif
 
 #include "node_parser.h"
 
@@ -63,9 +65,13 @@ NodeItem NodeParser::compute_full()
 std::string NodeParser::node_name(bool with_out_socket) const
 {
   auto valid_name = [](const std::string &name) {
+#ifdef WITH_USD
     /* Node name should suite to MatX and USD valid names.
      * It shouldn't start from '_', due to error occured in Storm delegate. */
     std::string res = MaterialX::createValidName(pxr::TfMakeValidIdentifier(name));
+#else
+    std::string res = MaterialX::createValidName(name);
+#endif
     if (res[0] == '_') {
       res = "node" + res;
     }