Presume I have a yaw value. This yaw value represents a point on the circumference of a circle. This yaw value is absolute - meaning that it is locked to the y axis in a 3D world. Now, I have a pitch value; This pitch value is relative to the yaw, meaning that the yaw is set, and the pitch then follows an axis based on the direction the yaw is pointing to point to a point on the circumference of the relatively created circle. Theoretically, using pitch and yaw in this way, our pitch value can point towards any location in a sphere with a radius of both of the circles' radii.
Now, presume we want to take the pitch and yaw values, and pass them onto another object - put this one has a $x$, $y$, and $z$ rotation axis, and none are relative to each-other. How would we do this?
Some more info: distances around the circumference of the circles are measured in radians; It is assumed the circle's all have radii of 1.
My first attempt to solve this was to take the radians and convert them into $x$ and $y$ values. So I used the formula $x^2 + y^2 = r^2$, and used $x = \|cos(x)| * y$ to find the x rotation, and $\|sin(x)| * y$ to find the y rotation. The thought was that when working backwards like this, I could use the original x and y values from the formula and multiply them by $y$ to create a ratio as to how far each of these went; This sorta worked, but did not give the desired result.