[Paraview-developers] Swapped "near" and "far" view frustum planes?

[anton.piccardo-selg at stfc.ac.uk]

Hi, 

I am currently reading out the view frustum via the vtkCamera. I am using ParaView 3.98.1. With the method getFrustumPlanes(double aspectRatio, double[24] planes) I can access the planes. The documentation states that the plane equation coefficients are returned as left, right, bottom, top, far, near. When I look at the output, then it seems that near and far are swapped. 

For example, I set my camera to look in the -z direction. The documentation states that the plane normals point inwards. Hence, I assume that the first three coefficients for the far plane should be 0,0,1 and for the near plane 0,0,-1. But just the opposite is the case. The other planes (left, right, bottom, top)  seem to point inwards. 

I am a bit confused by this. Does anyone know what my mistake or misconception is?

Many thanks and best regards, 

Anton