-Adrian Parker

That does it, thanks again!

Thanks goldleaf, you're right! I missed that.

It appears that I cannot remove the emission attribute without causing an unspecified cooking error, maybe because it's linked too intimately with the POP source. I tried removing other attributes though and that works fine!

I was using an emit attribute in SOP to drive the birthrate inside a POP Network. I now see that each particle inherts this property, which seems unnecessary.

Is there a way to remove certain attributes from particles? In my POP Source node's Inherit Attributes field, I tried
* -emit
which seems to have no effect. I also tried manually entering all common attributes while omitting my custom ones, but the nodes then fail to cook (no useful error report).

Any suggestions?