Definition of the STAR y2009a geometry.  The new "Geometry.cxx" scheme is used to create the AgML geometry.  The image below shows the control flag used to instantiate each geometry module, the name of the AgML module which is loaded, and whether the module is enabled in this geometry or not.  The color code indicates the status of the geometry.  Green means that the AgML module (compiled cxx code) exists, the control flag is defined, the shared library was successfully loaded and the module was instantiated.  Red indicates a failure in one of these conditions.  (n.b. Red and disabled is ok).

Next look at differentials.  To save CPU time I restrict the comparison to -6 < phi < 6 degrees.  Any difference > 1% within this fiducial volume will be flagged as "failed" below.  Any detector volume which is not present in this region will (unfortunately) automatically be flagged "success".

It is worth mentioning at this point that I've looked into the FPDM module at some level of detail.  There are some oddities in the way that the geometry is created.
In particular, the medium "leadglass" is defined twice. It is not clear what the behavior should be in this case, but it is (1) not likely to be what the author
intended, and (2) not consistent between AgSTAR and AgML.

The other issue I'm trying to fix is with the FTPC... At present there is a 1.5% discrepancy between the AgSTAR and AgML descriptions around eta=4.  (Note that only ~0.2 chi0 of material is present in this region, so this is a small difference in material.)  What is puzzling is that I don't see which volume is contributing to the material at eta=4.  Looking at all of the immediate daughters, and then a little deeper into the geometry tree...