You need to setup command for this.. its actually simple. if object picked up you send out command so object will set invisible for others -object can be idenified by its name.. so command can be "oVisible,nodename,false"
Script will parse this line as 3 parameters..
command:oVisible
par1:nodename
par2:value
setScenenodeProperty(getNodebyname(par1) ,"Visible",par2);
I have example for this actually .. i will upload example with many commands soon.