nested geomtries

Daniel Levin 313 764 4385 (DSLEVIN@umich.edu)
Tue, 28 Oct 1997 11:34:12 -0500


Dear ROOT Priests:

As a C++/ROOT novice I am flummoxed by the following problem:

I would like to construct a detector geometry in ROOT
from the bottom up alla GEANT. The examples harvested
from the tutorials (and from the na49.C file
created automatically from GEANT)
suggest only top down assembly. I.e.
first define a mother node:

mama = new TNode("MAMA","MAMA","MVOL");

//MVOL is the mother box...

place in it daughters: eg,

// PPLN point to BRIK shapes

mama->cd();
plx = new TNode("PLX","PLX","PPLN",0,0,zpos,"ROT1);
zpos += deltaZ;
mama->cd();
ply = new TNode("PLY","PLY","PPLN",0,0,zpos,"ROT2");

and then locate subsequent components as successive
generations in each of these exisiting first generation daughters.

How can I define some multielement fundamental detector subsystem
and then locate this system multiple times in a parent volume, then
place this parent multiple times in a higher generation node, etc?

thanx, Daniel Levin