Abstract: ther formats: WmvWmv We propose how to define complex geometry, appearance and tangible physical properties of the X3D and VRML objects using mathematical functions straight in the scene definition code or in loadable libraries. We can also touch and feel surfaces of X3D and VRML objects as well as convert them to solid tangible objects. We can define tangible density and force fields associated with standard and function-defined geometries. Since the function-defined models are small in size, it is possible to perform their collaborative interactive modifications with concurrent synchronous visualization at each client computer with any required level of detail. We illustrate this concept with several application examples based on our plug-in to X3D and VRML browser.