[esp-r] Re: Parent and Child surfaces

[Jon Hand]

Parent child relationships are used in limited ways - it allows the software to
initially assign the same boundary condition to the child.  It is used when scanning
for possible (linear) thermal bridge types and also to help clean up unused
vertices when deleting children.

The arrays in SURREL were sized to cope with the variety of models that I
had access to. Clearly none of them had that many children. As far as I
know bps does not use any of the child parent data structures. 

The other place where it could fall apart is that the number of edges in the parent surface
gets un-managable or exceeds the polygon array limits.  Most people cannot
reliably work with such complexity and that is the real limit.  I would say that
it would be better in the planning stage to recognize the likely complexity
and have more surfaces.

It would probably not be difficult to increase the array size in surrel.  And
if the glazing was a child of the frame then it would not have tripped the
logic.  Perhaps some logic could be added to detect and disallow really
complex situations.

-Jon
________________________________________
From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] on behalf of Adam Wills [adamwills at cmail.carleton.ca]
Sent: 08 October 2013 02:58
To: esp-r at lists.strath.ac.uk
Subject: [esp-r]  Parent and Child surfaces

Hello,

Are the established Parent/child relationships used in bps.exe? Or any of the other modules? Or is it simply for user feedback? Also, is it generally just bad practice to populate a parent surface with so many children?

I received an ESP-r model from a colleague of mine a few weeks back. It contained a wall with 4 child surfaces (representing studs, glazing, glazing frame, etc.). When I tried to view the zone containing the parent wall in prj.exe, I received a Fortran runtime error. I traced the error back to the subroutine SURREL in egeometry.F, which deals with determining parent/child relationships with surfaces. It doesn't seem to enjoy a surface with many children.

Cheers,

Adam Wills