update

added the following to the master script and it works fine

cutpl = GLOB_CUTPLANES_INFO[1]
st = GLOB_CSTORY_ELEV

- then replaced the variables in the add statement to the corresponding variable names above

I didn't check in 12, but it looks as if it is the same as

http://archicad-talk.graphisoft.com/viewtopic.php?t=8990&highlight=

Thanks to both of you for your quick responses. I haven't had a chance to test it yet, but am certain that this will work.

In retrospect, it looks obvious - the GDL compiler looks for anything that would be affected by changing contexts, and notes when it needs to reinterpret the script. If there is nothing in the 2D script that appears to depend on the current story, it thinks that the object's representation on the floor plan is constant and doesn't run the script again when you go to a different story.

It isn't smart enough to realize the link between the Project2 statement and the story-sensitive changes in the 3D script (the Cutplane statements that refer to Global variables for the current story), so one has to trigger the script reinterpretation with something it can "see".

I think I'll just use the simple dummy variable statement from the earlier thread:

dummyvar = GLOB_CSTORY_ELEV

since there is no need to break up the logic (and complicate the editing) into more areas in the library part. I want to create as simple and quick a process as possible for the user to follow after importing an object from 3DS. At this point, it looks like copying and pasting a few lines at the beginning and end of the 2D script and 3D script, plus the addition of one parameter (StorySensitivity), will be enough to make this functional.

As a wishlist item: build this story-sensitivity into library parts as a standard option, just like walls, windows and doors etc. have a choice of Symbolic or Projected representation.

I have verified that the simple dummy variable statement is enough to trigger the GDL interpreter to run as one changes stories. So my script is working now. Hooray!

For the record, and as a Tip for future reference, here is my 3D script for a test object that creates an inverted step pyramid. I created it so it would be easy to see the results on the floor plan as the Floor Plan Cut Plane parameters are adjusted.

if StorySensitive and GLOB_CONTEXT = 2 then
	add 0,0,GLOB_CUTPLANES_INFO[1] + GLOB_CSTORY_ELEV - GLOB_HSTORY_ELEV
	cutplane
	del 1
	if CutBelow then
		cutbottom = max(GLOB_CUTPLANES_INFO[3]+GLOB_CSTORY_ELEV-GLOB_HSTORY_ELEV,GLOB_CUTPLANES_INFO[4])
		add 0,0,cutbottom
		mulz -1
		cutplane
		del 2
	endif
endif

! STEP PYRAMID for testing
	ft=1'-0"
	steps=zzyzx/ft
	for i=1 to steps
		block i*ft,i*ft,ft
		addz ft
	next i
	del steps
! End of STEP PYRAMID

if StorySensitive and GLOB_CONTEXT = 2 then
	cutend
	if CutBelow then
		cutend
	endif
endif

Note that StorySensitive is a parameter to choose whether the object should be cut based on the Floor Plan Cut Plane - if it's not set then the object will be invariant for all stories. CutBelow is a parameter to choose whether to remove the underside of the object below the current story limit (or the Absolute Display Limit, whichever is more restrictive).

If the 3D script code is to be used with an imported 3DS object (or any other scripted object) then the beginning section above goes after the standard line:

IF AC3D_SHOW3D THEN

and the final section goes at the very end of the 3D script.

The 2D script is very simple. If one prefers showing the top view at all times, ignoring any LINE statements created by importing a 3DS geometry, then it is simply

dummyvar = GLOB_CSTORY_ELEV
project2 3,270,1

If, on the other hand, one wants to have the option of using the LINE2 and HOTSPOT2 statements from the 3DS import (or any other parametric scripting), then the beginning of the 2D script becomes:

if StorySensitive then
	dummyvar = GLOB_CSTORY_ELEV
	project2 3,270,1
	end
endif

with the rest of the original 2D GDL code from the import left intact.

Of course, more elaboration is possible, but this will give basic Cutplane functionality to any library part.

I was particularly fascinated to find in the ArchiCAD 12 GDL Reference Guide a new (to me) command PROJECT2{3} which allows the PROJECT2 statement to choose which parts of the object to include (cut polygons, cut polygon edges, view polygons and/or view polygon edges) with extensive controls for the projection hatches, fills and linework. It also offers the possibility of drawing the projection based on a different set of parameter values than are currently set for the library part. Wow! I'm not sure exactly how to take advantage of this, but it opens up a new world of options. I wonder if this is new in AC12 or was put into an earlier version but I missed it.

Hello NeckoFromSarajevo -
I have caught up with you here in the future (2014)...
Hard to believe we're up to AC17, with 18 around the corner!
Eric