I'm having a problem using G4PVPlacement to put G4Polycones inside of other G4Polycones. My initial observation is the definition of a local co-ordinate system seems to be different for polycones as opposed to a simple solid such as a cube. For a cube, the center of the local co-ordinate system is the center of the cube. For a G4Polycone, the reference frame seems to be the same as the frame used to define the (r,z) points of the polycone. I don't regard the above as a problem. Please don't change it. Polycones can be complicated enough without having to figure out where their centers are and translating objects to be placed inside. The problem is when placing a G4Polycone within the volume of another G4Polycone. The child G4Polycone is not placed such that its z=0 co-ordinate (as defined by its vertices) is placed at the z=0 co-ordinate of the mother G4Polycone; it's also not placed such that its z=0 co-ordinate is at the geometric center of the mother polycone. It appears to be placed roughly where the geometric center of the child is aligned to the z=0 of the mother -- the opposite of what one might expect from working with simple volumes. I should mention that I'm working on a detector with cylindrical symmetry, with the axis of rotation along the z-axis. The mother and child G4Polycones both have z=0 as their smallest z-coordinate, and I'm trying to place them such that z=0 of both polycones corresponds to z=0 of the world volume.
You can ignore this one and marked it as closed. The "problem" was that I was placing a G4Polycone inside a G4Polycone inside yet another G4Polycone, and I lost track of the hierarchy when I looked at a visualization of the geometry.
