Fixing bug with 3d plotting.
Fixing bug with 3d plotting.

r28329

joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven,idaholab/raven,idaholab/raven,idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,idaholab/raven,joshua-cogliati-inl/raven