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On Tue, 11 Aug 2015 01:59:31 GMT, Adam Glaser wrote:
> I was curious how GEANT4 can currently (or may be) possible to use for > modeling optics accurately. Would it be possible to define a geometry > solid/volume with a surface curvature defined analytically? I see that a > sphere can be defined, but how difficult would it be to define an > aspheric surface - such as those used in optical components and > commercial packages, e.g. ZEMAX. > > ZEMAX can export CAD files which could be parsed into GEANT4, but if I > understand correctly this will tessellate the surface which is not > desirable for accurate optics, and instead defining surfaces > analytically with known constants would be ideal.
Geant4 does not have parametric curved surfaces built in. We have spheres, ellipsoids and cylinders.
It is possible (and some user groups have done) to write your own G4VSolid subclass to implement a specific kind of shape optimally. You will need to look carefully at the G4VSolid.hh file, and maybe some examples of solid implementations in the source/geometry/solids directory, in order to understand all of the different member functions you must implement.
-- Michael Kelsey