[Closed] in coordsys parent math

Hi

I am trying to rotate an object about some axis defined by a coordinate system other than the world (e.G. the parent node). This can easily be achieved in maxscript like so:

in coordsys parent rotate $ (angleaxis 45 [0,0,1])
 

Unfortunately I am working with C# and the matrix3D class which doesn’t have such a convenient method (at least I couldn’t find it). So I’m trying to figure out the math involved with “in coordsys” rotation inside maxscript first. Do you know how that can be done? Any advice welcome.

thanks, David