message: require specific OSPRay version
diff: @@ -30,7 +30,7 @@ find_package(glfw3)
  set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
  set(THREADS_PREFER_PTHREAD_FLAG TRUE) # for gcc6
  find_package(Threads REQUIRED)
  -find_package(ospray REQUIRED)
  +find_package(ospray 1.7.1 REQUIRED)
  include(${OSPRAY_USE_FILE})
  