I am having some difficulties with adding ceilings to a simple model.
When I add a ceiling (and change no other geometry in the Revit Model) the roof plan in the GBS model changes the roof surface above the ceiling into a shading surface, which is fine, however it also completely changes the geometry. I have attached a screen shot of the VRML model in both cases. I was wondering if someone could help me understand what is going on with the model to cause this to occur and how to fix it.
This raises another questions I have had regarding shading surfaces, particularly walls and roof overhangs, I have noticed that at the point of change from where the roof changes to enclosed to open space a gap develops between the joined walla and roof, there is an example of this on the right corner of the attached picture. Any suggestions on how to close those surfaces or if they need to be closed.
Do you have the enclosed volume with the ceiling defined as a Space element (if using MEP) or a Room element (if using RAC)?
Also the upperbounds of the element defining the enclosed volume needs to exceed the top most point of the roof element. This will not affect the volume calculations of your model but will prevent the roof surface from being exported as a shading surface.
Regarding the gaps in surfaces--this should not affect the energy simulation results. Make sure the surfaces in your Revit model are properly joined.
Autodesk Green Building Studio Product Manager