3D Model Cubic Footage Calc.

I have a 3D model in Autodesk of an auditorium and I'm trying to figure out how to calculate the negative of the model to get the volume of the space. I have the section and plan if there is a way besides 3D to do this as well. Anyone have an idea?

Not sure if you can do that without LDD or Civil3D. In Civil3D it's very simple once you have an existing and proposed surface built.

(defun c:LeeMacVolume ( / ent obj )

(vl-load-com)

(if (setq ent (car (entsel)))

(if (vlax-property-available-p

(setq obj (vlax-ename->vla-object ent)) 'Volume)

(alert (strcat "Volume: " (rtos (vla-get-Volume obj))))

(alert "Selected Object Does not have a Volume Property")

)

)

(princ)

)

Please, thank Lee Mac for this Lisp, he is a member of this forum.