The reason I ask this question is that since I used a file from this forum, I noted where a population was used that had 'two' inputs for the object population (see image). That is why I thought a separate 'Populator' shader was available.
Note: Of the two inputs, one is for 'density shader', the other is for 'terrain'. One would think that since I've been so long with Terragen2, I would know this ...but I don't. Your help please!