Houdini 20.5: expose MoonRay Sdr Python stubs

CMakeLists.txt

@@ -20,3 +20,7 @@ find_package(Python REQUIRED COMPONENTS Development)
 
 add_subdirectory(moonrayShaderDiscovery)
 add_subdirectory(moonrayShaderParser)
+
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/sitecustomize.py
+        DESTINATION lib/python
+)

moonrayShaderDiscovery/CMakeLists.txt

@@ -72,3 +72,6 @@ install(FILES ${plugInfoFile}
         DESTINATION plugin/pxr/moonrayShaderDiscovery
 )
 
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py
+        DESTINATION lib/python/pxr/MoonrayShaderDiscovery
+)

moonrayShaderParser/CMakeLists.txt

@@ -72,4 +72,7 @@ install(FILES ${plugInfoFile}
         DESTINATION plugin/pxr/moonrayShaderParser
 )
 
+install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py
+        DESTINATION lib/python/pxr/MoonrayShaderParser
+)
 

sitecustomize.py

@@ -0,0 +1,19 @@
+"""Expose MoonRay's USD Python plugin stubs to Houdini's pxr package.
+
+Houdini ships pxr as a regular Python package instead of a namespace package, so
+adding MoonRay's lib/python directory to PYTHONPATH is not enough for imports
+such as pxr.MoonrayShaderParser.  The Sdr plugins are native USD plugins; these
+small Python stubs only prevent Plug from reporting missing Python modules when
+the native parser/discovery plugins are loaded.
+"""
+
+import os
+
+try:
+    import pxr
+
+    moonray_pxr_path = os.path.join(os.path.dirname(__file__), "pxr")
+    if hasattr(pxr, "__path__") and moonray_pxr_path not in pxr.__path__:
+        pxr.__path__.append(moonray_pxr_path)
+except Exception:
+    pass