QUCS - 3D Plot of Simulation - rotation axes are inconsistent - axes of chart/viewer's plane

[Circa-Tree]

QUCS - 3D Plot of Simulation - rotation axes are inconsistent - mixed frames of reference for axes of chart/viewer's plane

A simulation allows the use of 3D Plot for the results.
The 3D Plot settings allow the rotation about the "x", "y", and "z" axes.
Some of the rotations are made relative to the graph's axes, and others are made relative to the plane of the viewer.
These are mixed frames of reference, which should be applied consisently (which ever one/both is used).

This can be observed by rotating the graph around an axis by 45 degrees, then test the rotation (back and forth) about the other 2 axes. It can be observed that in some instances, all three graph axes are being rotated about the viewer's x axis.

Requirement ;

• unify the coordinate system that the transforms are being done in

Possible forms of solution;
a) use one "consistent" frame of reference, or
b) allow the choice between "graph axes" and "viewer plane axes" (both methods of which are currently being used together), or
c) allow the user specify the directions of each axis they want to have, and leave it to the system to figure out how to achieve it .

QUCS version 0.0.20
installed from repository into Ubuntumate 20.04 64 bit