There are lots of ways of generating clouds and simulate their evolution along time.

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This is my favourite scene of all the demo, and the one that more work took.
Take a peek on how we built planet earth with two spheres and three textures
Let's start discussing about the demo editor and engine. A procedural approach could be better than a task-oriented one, from the point of view of scene creation?
BCN Party was an event held from 1-3 November 2002 in Centre Cívic Casinet d’Hostafrancs, in Barcelona, Spain
This little article is a series of trivia about inferno. Looking in perspective it was a minor release, but for us it was the most complex demo we ever built!