"Not nessisarily. They could implement 2d particles." You're right. 2D would probably be the way to go for such things as weather effects in Vue, considering most people will use them in "distance" landscape shots, and not close-ups. But it would be nice to have the option to set them as 3D as well, so you can use them with metablobs and for "close ups" with 3d motion blur (if Vue has this). Also for things like flowing water, although for distance shots this could be faked with 2d particles as well.

---

Tools :  3dsmax 2015, Daz Studio 4.6, PoserPro 2012, Blender v2.74

System: Pentium QuadCore i7, under Win 8, GeForce GTX 780 / 2GB GPU.