If you know it's a virtual child then almost certainly not (except, perhaps, in .au, which I think at least had statute defining even obviously cartoon depictions of naked minors as child porn).

The caveat here is that these (alleged) perps all believed they were interacting with a real child. In Common Law countries, at least, criminality exists in the presence of mens rea — the "guilty mind" — and actus reus, an overt action.

Virtuality or not, if you think you're chatting up an actual, breathing, 8-year-old girl, and offer money for her to remove her undergarments, you are a criminal.