Volume using 3D Polygons

[Phileas]

I suspect this has been answered several times, but I haven't been able to find a working solution for my problem...

 

So here's the thing: I have to add an acroterion (not sure of the translation, I'm talking about that part of a roof:)

 

I have no trouble doing that for most of the building, but the intersection of 2 specific walls has really been a pain in the a** to model and I'm stuck.

Here's the situation:

 

My Acroterion needs to have a fill when looked at in a section view, so I first tried to use wall styles for it. The intersection of the 2 walls ended up being as weird as the one you can see in my last picture.

I then switched to using extrudes (drawing 2D Polys and extruding them, then moving/rotating them, into their final location). I came to realise that it's probably geometrically impossible to have a clean intersection on the upper and lower face of 2 intersecting extruded planes that don't have the same slope without varying their thickness, which would be kind of complicated to do using extrudes since I'd have to use multiple rotated extrudes as solid substractions to cut off the excess parts of the 2 original objects, and that already sounds very time consuming.

I then tried to use 3D polygons to draw each face of the shape I want for my finished object manually. That workes like a charm, the result looks exactly like the thing I wanted to create when you look at it from the exterior. However, in a section view, the 3D Polys do not show a fill, even though they form a closed volume (a quite complex one with varying thicknesses but still a clean 3D volume).

So my first question is: Is there a way to change an assembly of 3D Polygons that form the faces of a closed 3D Volume into a volume to which you can apply a fill?

And If that's not possible: Any other Ideas on how I could solve my problem? The walls do not have the same slope btw.

I managed to solve this for the roof you see on my picture. But I had to use 2 different roof face styles with different thicknesses and adjust them millimeter by millimeter manually and that took hours.... I was wondering if someone had a better way to achieve a decent result

Edited February 11, 2019 by Phileas