The g_qa tool looks like a nice one but has a serious
flaw when reporting overlaps: adjacent surfaces are
shown as overlapping when rtcheck doesn't.
The attached simple TGM (bug.g) has two boxes, 10 mm
on an edge, touching on one face. The two regions'
solids were generated by:
in s1.s rpp 0 10 0 10 0 10
in s2.s rpp 10 20 0 10 0 10
so you can see the adjacent faces are perfectly
The attached file, bug.txt, shows the results of using
rtcheck and g_qa on bug.g.
I'm not sure if there's anything that can be done
since I believe g_qa shoots along (parallel to) the
adjacent faces during its travels, but it is a bother
and reduces its utility somewhat.
This was version 7.8.0 of BRL-CAD.