I want to be able to get the items with a Z(0,0,-1) value and multiply the whole item by -1 to get the opposite value. Then append that new value into the same list, changing only those with a Z(0,0,-1) value.
If you’re dealing with “planes”, then check this demo.
FlipPlanes_re.gh (12.6 KB)
I actually might of solved it through another question you answered. Will confirm tomorrow.