Is there a rule of thumb, when PRISM_ s are hiding there edge lines when connecting with other PRISM_ s in the same object? In the image you can see, that sometimes there are edges visible and sometimes not. The arrows also show edges that are visible now, but disappeared in some cases (not reproduceable).
As there seems to be no reliable rule, the best thing seems, to make the edges at connections invisible, to use the masking values of the PRISM_ command.
GDL Object Developer
MAC OSx 10.14