[vtkusers] Light bug !

[Sebastien Auclair]

Greetings !

I'm looking for clues (not necessarily a bug-fix) related to a bug we have !
Our application has 1 camera with only one light set to follow it.
 Renderer->LightFollowCameraOn();  )

Moving the camera moves the light fine but changing the coordinates of the
points of an object so that it rotates seems to also affect the light !!
NOTE: We don't use any WindowInteractor. We've implemented our own based on
the code for vtkInteractorStyleTrackballActor\Camera.

BUG EXAMPLE:

If I have two cubes A and B with their facet 1 facing the camera.
Only one light placed at the camera position.
For both cubes, the facet 1 receives all the light.
I rotate cube A on 90°\Y by modifying the point coordinates directly in the
dataset at the beginning of the pipeline.
The result is that the cube A is rotated alright but so as the light in
relation to cube A.
And cube B is still receiving light on his facet 1. !!!! (Like if we now
have two lights !)
The facet 1 of the rotated cube A still receive light directly.

Any clues on this behavior ?

Thanks !
__________________________________________________________________
Seb