There are now a large number of Xfrog-based sets of plants in the RMP that are simply bitmap cutouts, all from the same vendor. Has anyone used any of these, and if so, what do you think of them?

Billboards are alpha planes, so they are 100% flat. they are good for background filling, but if they are to close to the camera, the flatness will show, and the shadows will look wrong too. Just turn off cast shadows when using them. But they are useful though. And cheap. Just think that you can create billboards yourself with Vue trees.

The vendor is Greenworks, who make Xfrog, so they are legit and of good quality. As bruno says, they are very useful for long distance shots where you need a forest, but don't look so good close up. For distant forests they are excellent because they are so low poly.

If you buy the most recent DVDs of Xfrog plants they come with the billboards already included. Likewise if you buy individual plants from Cornucopia, you get the .vob format and the billboard.

I wondered who Greenworks might be ...

They may be low-poly, but AFAIK what is killing Vue for me is not the polycount but the bitmap sizes.

Greenworks is a german based company who created the XFrog software, as long as all the plant libraries; most of the libraries were made by Walli & Orio, whom you may know from this gallery.

Their plants have been used in many feature films, including War of the World (and I think they were the only interesting bit in this lame movie!), the Incredibles, The polar Xpress, etc, etc...

Check their website:

http://www.xfrogdownloads.com/greenwebNew/news/newStart.htm