Attached Link: http://lucbianco.free.fr/tgd_index.html

See above link for a peak at Terragen 2 clouds...

Of course Terragen 2 is going to have some very beautiful cloud effects as well. But keep in mind that Terragen is a FRACTAL based software and uses a different rendering engine than VUE. However, CLOUDS are going to be one of the next big WIZ-BANG effects in the "race" between programs like Vue, Terragen and Bryce. Vue can certainly respond quickly, I believe, by making use of its existing Bill Board and Eco-Systems Instances methodology and creating CLOUD-SYSTEMS. (The sooner- the better!)

See this below link for the EARLY BEGINNINGS of Terragen as a DOS based Cloud Generator using Noise Octaves...

http://freespace.virgin.net/hugo.elias/models/m_clouds.htm