Hi all, I am trying to use the ROOT Geometry classes to define the geometry of a testbeam setup. I want to use this for an event display, and eventually by deriving my own classes as a simple database for by detector setup. Looking at the available classes it seems to be that the set of classes is not completely developed yet, i.e. some classes are not complete, and I would wish/like additions. Is there any activity at the moment on these classes, or do you advise me to use another mechanism to implement my detector geometry? What I would need/like/miss: 1) For some(/most) of the TShapes I'm not able to 'Get..()' the defining variables (i.e. like rMin/rMax etc.. of TTUBE). I would like to be able to do this, if I would use them as a sort of detector-database. The members are all protected, so I could derive from them. But I don't think this should be the right way. 2) The 'first' contructor of TRotMatrix (i.e. TRotMatrix(Text_t *name, Text_t *title, Double_t theta, Double_t phi, Double_t psi); is not implemented. 3) TELTU seems to be implemented as a normal cylinder, not as a cylinder with elliptical cross section. 4) In my setup I have several types of detection elements/cells, which all have the shape of a 'cylinder' of a certain lenght and a varying shape of the cross section (i.e. cylinder, elliptical, honeycomb etc...) So I would like to have a shape with 'arbitrary' cross section (defined by an array of n points in 2d) and lenght l along the (z)-axis. As far as I know, I can't use any of the available TShapes to make such shapes. This could also be solved by the following... 5) Geant (on which the classes are based) has the mechanism to combine volumes with simple boolean operations (GEOM020). It would be great to have a mechanism like this for the TShapes. We could begin by defining something as a TCompositeShape. Ofcourse I could implement this partly by defining a TNode which combines a few TNodes with the shapes I would like to combine. But in this way I only have the possibillity to 'add' ('union' in Geant) shapes, not to substract them! => not possible to make all shapes... This are just some points which came to my mind the last few days working with the classes. I would like to stress that I am already quite impressed by the simple way I can define 'simple' geometries. I think my basic question is if there is anybody working/developping these classes at the moment, or if we can expect anything in the near (!) future. Thanks, Rutger van der Eijk
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