message: Use Ptex in viewer
diff: @@ -22,12 +22,14 @@ find_package(Boost COMPONENTS chrono filesystem iostreams system thread REQUIRED
  find_package(GLEW REQUIRED)
  find_package(GLUT REQUIRED)
  find_package(OpenGL REQUIRED)
  +find_package(Ptex)
  find_package(Threads REQUIRED)
  visionaray_use_package(Boost)
  visionaray_use_package(GLEW)
  visionaray_use_package(GLUT)
  visionaray_use_package(OpenGL)
  +visionaray_use_package(Ptex)
  visionaray_use_package(Threads)
  # CUDA
  