You can do this using sim.can_move(type1, type2, 2) where type1 is your radiation particle and type 2 is the particle you want it to be able to. For example, if you want a radiation particle called "RADI" to be able to move through METL, you can use sim.can_move(elem.YOURSCRIPT_PT_RADI, elem.DEFAULT_PT_METL, 2)

Sadly, there currently isn't a good way to do this. The best way is as follows:

for i=0,2^sim.PMAPBITS-1 do
if i ~= elem.DEFAULT_PT_INSL and i ~= elem.YOURSCRIPT_PT_CUSTOM1 then
sim.can_move(elem.YOURSCRIPT_PT_RADI, i, 2)
end
end

The caveats include:

• Make sure you put this code after all the places in your script where you allocate elements. Otherwise, elements allocated after this code runs will not interact with your element correctly.
• There is no guarantee it will work with other scripts. Sometimes it will, and sometimes it won't, dependent entirely on what order the script manager decides to load them in.