As many of us hope, one day (!) ArchiCAD will be able to produce beautiful renderings directly without having to use any other 3rd party application. At that time, all the material definition will have to be done in AC...
Materials should then be more controllable, as in specific rendering applications : one should be able to use different bitmap / alpha channels for specific properties : gray bitmap or shader would be used to define individually the bump | transparency | reflection | etc. properties for each material.
