First of all I have never tried using shared coordinates with Revit. However I have found this video quite good at explaining how it works: http://www.youtube.com/watch?v=aSxbv7QPero
I do have a few questions which popped up in my mind.
1: He is using shared coordinated on a wall. Wouldn't it be wiser to use shared coordinates on two points on the grid instead as the grid will never change and the walls might.
2: If I set my shared coordinates on 2 points on the grid I am thinking about using the Z value of the basement elevation. How does the person using Revit set the shared coordinates in his model as it is not 2 spots on a wall but two spots on a grid?
3: In the video he is exporting the Revit model to .dwg. Is it possible to dynamically insert the revit model in C3D so that I always have the newest model inserted?
4: I create my piping based on the position of the foundation. Is it possible to have a dynamic model in which I can only see the foundation?
I hope all the above makes sense - I'm sorry if the questions are a bit stupid but I do not have much experience in using C3D - yet!
All the best,
Comments / answers.
1. Yes the grid or annother known point in both models would be better.
2. the definition files use a point xyz and rotation value so unnessesary.
3. he is exporting from Revit Architecture using ADSK file, which is not avaliable from any other version. Rvt files are not native to civil 3d so no. Best workaround is to export a 3d drawing from revit.
4. See above, exported file. Not Dynamic.
Generally The two do not like one annother. Happy playing.