What corruption is causing this roof plane to not be editable? See thread in Suggestions "Pls fix roof problem"

[GeneDavis]

I got into this one with comments about roof generation in Chief and editing, and could almost get the roof I wanted, but something kept happening to one of the planes that I could not understand.

 

I always thought you could raise a single roof plane with the move tool and wanted to hold fascia height and pitch and move in the z axis up or down, to be able to get a matching fascia height all around.  The OP's file with my edits to roof planes is attached as Plan Rev 1.  The screencap identifies the rogue plane.  I tried everything I could think of to get the fascia top at 110" to match all others.  At one point I thought I had it but something caused it to move.  What could it be?

 

You can delete the plane, take the 12-pitch plane to its immediate R and copy-mirror it, the copy works and has the 110" fascia height, but when you edit it to join the others, the edit causes the fascia height to drop 3/16".  This, with the 12 pitch staying same and the two roofs joining at top dead center.  Makes no sense.

 

The OP built the example file with weird defaults and settings?  I don't know.

 

I made a perimeter polyline of the "house" and copied it and pasted into a new file with my template, and auto-built the roof with appropriate settings, one wall only at 4:12 pitch, creating the irregular hip and valley where it joins the 12-pitch adjacent planes.  No problems with that one, attached here as Plan Rev 2.  As with roofscapes that have irregular valleys and hips, you need to manually edit fascia and subfascia to get things in perfect alignment, which I did for both plans.

 

But what's up with that Plan Rev 1?

Plan Rev 2.plan Plan Rev 1.plan

[JLU_Design]

This is how I've overcome this in the past.

It's not really ideal though.

You need a little gap between the fascia so they don't "snap" together.

Chief auto re-adjusts for some reason.

This is a really tight view of the roof plan view:

[GeneDavis]

 

I am starting to see where the inaccuracies are with this.  Chief hints at it in the writeup they give in the HELP dialog when you open HELP from the roof plane dialog panel.

 

I'd like them to explain better.  They say, "Note: The Fascia Top height will decrease slightly if the fascia edge is aligned with the ridge top of another roof plane."

 

This seems to hint at why you cannot get an exact match to fascia heights going around a roof where there is a plane at a different pitch from others.  In the case of 12 pitch to 4 pitch, 12 around perimeter with one 4 in the link, that "slight decrease" is 3/16" as reported in the roof dialog for heights.

 

In a 2D section view and measuring using Chief CAD, in the L-shaped example you posted in your thread in Suggestions, two mating 12-pitch roofs are reporting, in the roof plane dialog, fascia heights of 109 13/16 and 110, a 3/16 height difference.  But a 2D back clipped section cut through the building has fascia tops not at either of these two numbers, but close to 110 11/16.  Using CAD, one measures 9' 2.7193542495" (110.719" to 3 decimal places), and the other at 9' 2.7071067812" (110.707").  A 3D view of a corner where two roof planes join, the one on L reporting a fascia height of 109 13/16. the one of equal 12-pitch on R reporting fascia at 110, but as can be seen in the vector view with roof surfaces peeled away so just the fascia can be examined, both fascia tops are equal and coplanar.

 

So we have Chief reporting fascia heights that when measured in section are almost 3/4" different from what is reported, and fascias showing in 3D as having equal top elevation, but reporting as 3/16" different in the dialog.

 

I'd say Chief has some 'splainin' to do!