hi *,
my math is getting worse each day 
… ok, my problem (it is simple, i fear): i have an object (plane) and i want to position another object relative to the first one. meaning that the orientation/position of the first object is the coordinate system for the second. this is urgent, because it is the last showstopper for finishing my gameBlender python project…
thanks in advance.
and a child object is not good enough
(or a vertex child?)
control+p // parent
control+alt+p // vertex parent
(I did this last that I remember having diamond shaped object the child of a square picture-frame like object, and you could move the diamond object around with the mouse, and the coordinate system used when moving the diamond object was transformed when the picture-frame (parent) object was moved, rotated, and/or scaled)
ne, thats not enough… 
you got it right, it is for mouse movement. the problem is: when i set the position of the object via objet.setPosition , blender does not care about parent/child relationship. i could manipulate the object via actuators, but there’s a problem: the motion actuator onply supports movement, and that does not look good with mouse-moved-objects, because you change the position of the cursor by moving the mouse, you do not move the cursor. any suggestions?
corban
OK, am home now, can say stuff more accurate…
I don’t know about python setPosition, gameBlender, and VERTEX CHILDREN, not having tried it.
tries it
err, moving vertex children with setPosition is odd, but works.
Ok, back to what I intended to say, my object was made the child of the other object when they both were at the origin. Was your parent object at the origin when it was made the parent?
It works fine for me yet again
thanks, z3r0 d! it was the origin. it is quite cool to be able to set the position of one object relatively to another via setPosition.
greets