Wow, this is an interesting thread. Tough subject! As a relative new-comer to digital art, I've had numerous thoughts pass through my head on this subject. I'm not really presenting any answers her, just food for thought. So what follows are only personal observations and feelings and are in no way meant to disrespect or belittle anyone else's work.

That said, personally, I have a apprehensions with collecting a bunch of free, ready-made models, Poser figures/clothes/poses, textures, atmospheres, and presenting the rendered assembly as 'MY' work. If I need a model/prop/texture for my image, I feel a better sense of artistic integrity if I at least try to create it myself. However, I, and many others, don't have the skills or tools to model a human being, animals, and many other things. So it is almost essential that to some degree, someone else's work will be included in one's render at some point. There's nothing wrong with that, but I don't feel comfortable presenting an element I did not actually have a hand in creating as my own.

I also do not agree with the brushes/paint comparison stated previously. Those are tools, and regardless of the tools, a painter and their skills are responsible for creating everything in the image presented on their canvas. Not so with the 3D digital art being discussed here. A more realistic comparison is with sampling in music. If a rap artist samples a Van Halen guitar lick off a CD and includes it in their own work, should a credit to Van Halen be given? Well, I think so.

But how far does that philosophy go? You have to find the line between your tools and your content. I mean, someone had to create the plants, trees, textures, atmospheres, included within the VUE program (not speaking of the extra sample scenes). But do we give credit for each of those things? That would be a bit extreme and absurd. Going back to the music comparison, that would be the same as a keyboardist giving credit to everyone who recorded piano, trumpet, and violin samples for their internal keyboard sounds. In this case, just saying you used VUE, or Poser, is enough.

On the other hand, an argument could be made for photography: Should the photographer be expected give credits for each specific element included in the photo they happened to shoot? Obviously not.

Every individual is going to have their own opinions about where to draw the line between what's their own work and someone else's; between creating a piece and just 'assembling' it from other's work. I'm just grateful that there is such an amazing amount of resources available on the web for digital artists, and I'm grateful for the people who created them. I'd feel honored if someone else used my work within their own. But I'd also like it to be acknowledged. So I'll always do the same for others whenever it's possible/practical.