For the surface below, the viewer angle with the x-axis is 60 degrees and the viewer angle with the z-axis is 85 degrees.

For the surface below, the viewer angle with the x-axis is 60 degrees and the viewer angle with the z-axis is 85 degrees.

For the next two surfaces, both the screen x- and y-intervals are .  The viewer angle with the x-axis is 45

 degrees, while the viewer angle with the z-axis is 85 degrees.

The presence of the  term in the formula for the above surface suggests a conversion to cylindrical coordinates, where the surface equation becomes

the viewer angle with x-axis is 50 degrees and the viewer angle with the z-axis is 88 degrees.

the viewer angle with x-axis is 45 degrees and the viewer angle with the z-axis is 80 degrees.