Hello,
vtkCamera has the setViewAngle(double) method which sets the field-of-view angle (30º by default, ignored if projection is set to parallel). It is not possible to set two angles with that method. To achieve that (you’ll end up with distorted aspect ratio, I must warn you) you have to call UseExplicitProjectionTransformMatrixOn() and set the projection matrix manually. Please, take a look at this (c++ - What is the difference between ProjectionTransformMatrix of VTK and GL_PROJECTION of OpenGL? - Stack Overflow) to get started with setting projection matrices. Even though, you can’t set the vert/horiz angles directly. You have to express them as vert/horiz and horiz/vert ratios. In the figures below, you have a typical viewing frustum used in perspective projection and how the parameters relate to elements in the projection matrix further below.
figures taken from: OpenGL “Red Book”.
take care,
Paulo