I'm a new user of grasshopper and I want to know if someone has a method to generate elevations (or plans/section) of a model in Grasshopper, that can change if we make modifications in the model.
Use the Brep Wireframe Component to get the edges and then flatten the control points to a plane by omitting the desired value. Then reconstruct the lines. The example below shows polylines but if there was a way to obtain the degree of a curve you could reconstruct them by using the Control Point Curve Component.
Another possible option (although not available right at this minute) might be related to something I'm working on. I'm looking at linking IFC (Industry Foundation Class, which is a neutral BIM file format) generation from Grasshopper as part of the Geometry Gym plug-ins. If you can import your model into a BIM program that can generate elevations, plans etc, it would also be automated. http://geometrygym.blogspot.com/2010/06/ssirhinoifc-progress-indust... is a post describing progress.
One thing to consider with this type of workflow is that it would be primarily one way exchange (as Grasshopper tends to be a generator rather than a manipulator). The actual Rhino plug-in would allow exchange both ways. As with all my work, priority is given to users requirements and suggestions, so if it sounds of use, get in touch and I'll explain further.