Walls cutting below roof-Part two

[Anonymous]

I'm using AC11, Win 1114 Full
I'm trying to cut parapet walls; but, when I cut the wall, I do not get a cut line at the roof I'm trying to trim it to...my wall is getting cut at some abitrary (arbitrary to me, prob not to the program) point further below the roof plane.

I need to post twice to show both views (a before and an after shot)

[Anonymous]

And here is the result I'm getting....

any suggestions as to what could be happening? I have tried this operation several times, in several different sequences.

[Anonymous]

looks like you've got two roofs there? like inner and outer (bottom and top?)

so the wall gets trimmed to the first roof it encounters...

select the wall in 3d, and the top roof that you want it to be trimmed to, in order to 'force' the trim to be to the chosen roof rather than the first roof plane that the wall encounters.
hth.

[Anonymous]

I do have two roofs-one is my cutting plane, so to speak. I turn off my 'real' roof, and in 3D do select the 'cutting plane' for this operation. It isn't really cutting back down to the 2nd roof (real roof); I'm having this problem on another part of the building, whereas I am not using an additional cutting plane, but using the 'real' roof as my cutting...it seems like some of my parapet walls (those walls above my ceiling height, and which do not go do floor slab) are having problems. Not all of them, but just a few.

[Anonymous]

A few points Kathleen,

a) Try using SEO instead of trim to roof. It remains associative if you move the roof and I find it more reliable. Set it to subtraction with upwards extrusion with the roof as the operator. For neatness manually stretch the height of the wall beforehand, to the maximum height it will be after it is trimmed. Put the dummy roof on a hidden layer.

b) Make sure the roof actually overhang the walls fully, whatever the method of trimming you use.

c) There is probably an obvious reason, but why are you using the internal hidden line mode for actively editing and modifying the model. I don't know your experience in ArchiCAD, but I find it impossible to use. OpenGL is so much faster and fluid for day-to-day use. I only switch to IHL mode to check material fills and alignments, or to extract line views of the model for editing later. Apologies if I'm teaching you to s uck eggs!