The deserts of arrakis there is no vegetation, no scale reference for the eye to look at and know how big things were. which is good and bad means that we had to have almost a full simulation of all the different grains of sand in their, to make that work. so early testing we did with the sand grains were just too big, the worm didn t feel as imposing and as massive as it needed to be. so the effect team had to come up with different ways of working with that, obviously you can t simulate every single grain of sand in the desert, that is not possible. so they came up with systems where you can have a representation of what it is likely to look like, and you had to have several systems that would call from a library of different setups that we had to then populate some of the areas around the worms to get that feeling of yes, this is the desert, and those sand grains are tiny. and from those simulations we had dust coming