Merge *with* SEO between composite wall and roof intersection in section

[Paul King]

Hi, I am bumping in to an issue where if I SEO subtract a composite wall with upwards extrusion from a sloping composite roof, then by default the composite skins do not clean up with each other in section.   However If I then use the merge function between the same two elements, the SEO operation is ignored, and some skins of the wall poke through the roof again (depending on materials priority).

How do I achieve SEO subtraction of walls from roofs with clean up between composite skins in cross section?

I have not tried trimming the wall to roof instead, because I want the walls to automatically follow changes in roof pitch & height as the design evolves in more detail.

Operating system used: Windows 11 23H2

[Barry Kelly · Accepted solution]

Solid Element Operations (SEO  - some one will ask what this is), ignore the skin building material strengths and and will trim a wall to the underside (upward extrusion) or top surface of the roof (downward extrusion).

The Connect > Trim Elements to roof shell is based on the building material strength and is a live connection like SEO, so you can adjust your walls roof and they will adjust accordingly.

The old Crop to Single Plane Roof command is a fixed crop and will not adjust as elements are altered.

Barry.

[Barry Kelly]

I should also say the connect trim to roof uses the roof trimming body as well.

The SEO does not.

Neither will show the correct cuts in plan.

Barry.

[Paul King]

Perfect, thanks Barry!

For some reason I have been assuming all this time that 'Trim elements to roof' was a variation on 'Crop'.  Not quite sure where I got that idea from.

[Paul King]

A trap for young players is that Trim to roof also cuts walls in plan at the roof pivot line, unless you change the cut projection mode to full roof profile

[Barry Kelly]

Slabs and walls should automatically trim based on building material strength if they are in layers with the same intersection group number.

From the help reference ...

https://help.graphisoft.com/AC/27/INT/index.htm?rhcsh=1&rhnewwnd=0&rhmapid=#t=_AC27_Help%2F040_Eleme...

Barry.