Get the new relative position of an object that draws to a to jit.gl.node

hi,
let say you create a simple gridshape. You tell this gridshape to draw to a jit.gl.node. Now you change position of this node in the 3d space.

Is there a way to retrieve easaly the new relative position of that gridshape, therefore without to make a calculation of the new coordinates

(i mean is there an argument or an already packaged feature that does it ?)

In short this is what i want to achieve :

let say i have 3 gridshape spheres.
- At first they draw to jit.world. I can retrieve coordinates in the world context.
- Now i d like to group these spheres so i can apply transformation to a groupe of objects, and i believe the best way is to create a gl.node (call "group1), and tell these spheres to draw to this node.

- Now i change position, or rotate "group1" - i would like to be able to retrieve the new position of each of these spheres in the world context.

Any idea of the best way to do this?

example patch :

thx!