Would anyone like to generalize the Shear operations in x, y, and z?

in x:

 1 dy dz   
 0  1  0  
 0  0  1  

in y:

 1  0  0   
 dx 1 dz   
 0  0  1   

in z:

 1  0  0   
 0  1  0   
 dx dy 1   

And @doodooloo, what if we want a shear in x-y, based on z? (you gave us a shear in x, based on y and z position.)