Walls trimmed by roof are visible at upper roof plane.

[Robert Nichols]

I probably knew the answer to this at one point, but baffling me now.

I have interior walls that are trimmed by a roof above. But the cut is apparently occurring at the top/exterior plane of the roof, rather than the bottom interior side of the roof. Thus, I am seeing the "footprint" of the walls on the top of the roof where I should be seeing uninterrupted roof finish material.

I get the desired result when using conventional SEO operations, but the "trim elements to roof/shell" is easier to use, and I'm accustomed to getting the desired result with that command.

What I am overlooking?

Thanks.

[David Maudlin]

Robert:

This is caused by the strength of Intersection Priority of the Building Materials: the Wall should be weaker than the Roof.

David

[Dontknow]

Here is a video how it works.

[Robert Nichols]

Thanks, David and Dontknow. I just spaced out for a second there. When you've been using ArchiCAD since v4, every feature that came since then still seems new, and I forget about them! Obviously, material priorities were a very welcome improvement when they showed up.