Contour angle [toon material]

[zooropa]

Hi I am been working with the toon material for the last week in order to deliver some projects.
The parameter contour angle has been really helpful so far. The model is coming from SW and Rhino so I can 'clean' iso-curves while changing this parameter (from 0 degrees to 180). At this moment the camera is facing the model from almost a frontal view (almost orthogonal tu the object) and regardless of tweaking the inputs of contour angle ...the toon material is showing me always the same lines without any change in the visual outcome. Is it cause the camera position ?