Add Vulkan support

Signed-off-by: Dan Bailey <danbailey@ilm.com>

Author: danrbailey

openvdb_houdini/openvdb_houdini/CMakeLists.txt

@@ -123,6 +123,8 @@ set(OPENVDB_HOUDINI_ICON_INSTALL_PREFIX ${OPENVDB_HOUDINI_INSTALL_PREFIX}/config
   CACHE PATH "Install path for the OpenVDB Houdini node icons")
 set(OPENVDB_HOUDINI_PYTHON_INSTALL_PREFIX ${OPENVDB_HOUDINI_INSTALL_PREFIX}/python2.7libs
   CACHE PATH "Install path for the OpenVDB Houdini startup script")
+set(OPENVDB_HOUDINI_GLSL_INSTALL_PREFIX ${OPENVDB_HOUDINI_INSTALL_PREFIX}/glsl
+  CACHE PATH "Install path for the OpenVDB Houdini GLSL shaders")
 
 #########################################################################
 
@@ -395,6 +397,9 @@ install(FILES
 install(DIRECTORY help/
   DESTINATION ${OPENVDB_HOUDINI_HELP_INSTALL_PREFIX})
 
+install(DIRECTORY glsl/
+  DESTINATION ${OPENVDB_HOUDINI_GLSL_INSTALL_PREFIX})
+
 if(OPENVDB_INSTALL_HOUDINI_PYTHONRC)
   install(FILES
     pythonrc.py