Here is a small tree I made using one of the Onyx softwares:

As you can see, the leaves are so low-poly, that it's impossible to make them look convincing. I can raise resolution of the leaves, of course, but that doesn't help at all, because I cannot apply the fold/bend/twist modifiers to individual polygon islands but only on the whole object. So how to I add some randomness in the shape of the leaves and add some curl to those at random? Is there a way to isolate all polygon islands as separate meshes? Will it work then?
The second question is, if I fail to do all this, and am forced to replace those leaves with my own, how do I do that? I have read 'Making Of's in the Evermotion website that spoke of such a total leaf replacement in a tree, but I cannot imagine how that is possible without manually putting every leaf in place or executing some fairly complex algorithm (which I also know nothing about).
Thanks in advance!
The suggestion does not essentially have to be about XSI. I can try to do it in some other software as well, if I must.
