Erich,......
think of the "flutes" as negative space.
you could make a mass, say a corner cube with 3' x 3' x3' size.
then make another object using the morph command to take on the shape of the "negative" space of the flutes.
Then, position the "negative" space object to intersect with the "mass".
Then, use the "SEO" tool, subtracting the negative space object from the mass.
Then, look at the object in 3D. It will then only show you the mass cube with the subtracted flutes.
Then, while still in 3D, go to the "SAVE OBJECTS AS" in the library parts and it'll create what you need in 2d/3D
Now...mind you it won't be parametric in the number of flutes you can add or change but, you'll have that shape.
...Bobby Hollywood live from...
i>u
Edgewater, FL!
SOFTWARE VERSION:
Archicad 22, Archicad 23
Windows7 -OS, MAC Maverick OS