Cutting the buildign footprint in the toposolid surface

[mariaome1991]

I have create a toposolid surface with elevation points in Revit. I have a building that has a basement that has ungrouped elements, it is not grouped. How can I cut the footprint of the building in the toposolid? i wan tto be able to view the building underground in section. 

Kind regards

[barthbradley]

cut it with a mass and hide the mass. 

[constantin.stroescu · Accepted solution]

Create a Mass Void that follows your basement overall volume and Cut the Toposolid with it

[mariaome1991]

I have tried to cut the solid void with the cut tool. Do I have to select the site first and then the void solid? 

Also I have tried to adjust the depth of the solid void so that it cuts into the site mass.

Could you offer step by step instructions?

Multumesc frumos pentru ajutor. 

[barthbradley]

Is this what you are trying to do?

[barthbradley]

Never mind. I'm outta here.  I've got a planet to save. 

[kelly.colyn]

...how does this work on an uneven surface praytell?

[barthbradley]

not clear what the question is.  

[kelly.colyn]

You give an example of cutting a void in a flat surface above. ...I was asking how to properly make a vertical void cut in a toposolid that is uneven? See screenshots below.

For context, when i place a void cut on the toposolid, with the 3D snapping box checked, i can only make a void within the triangular 3D face of the topossolid.

Without the 3D snapping box checked, I recieve an an error that the void is not cutting anything. 

...any help would be appreciated, thanks.

[barthbradley]

Create the Mass IN-PLACE.  In other words, go to Massing & Site Tab in the Project and pick In-Place Mass.