Combine several dimensions' detail settings into the one directive a pass
receives: the DEEPEST explicit pin wins (a pinned dimension must never be
drawn below its setting because another one is on Auto), else 'auto' if
any dimension asks for it, else null (time-budgeted).
Combine several dimensions' detail settings into the one directive a pass receives: the DEEPEST explicit pin wins (a pinned dimension must never be drawn below its setting because another one is on Auto), else
'auto'if any dimension asks for it, else null (time-budgeted).