Dubai was a level which had shaders that were almost exclusively handles by Roel Coucke. The main challenges here was the huge amount of sand and white panels that make up the level. The white panels were largely broken up by decals.
The sand used projected map1 UVs so that there were no material breaks between adjacent sand materials. There was also a lot of use of custom sand decals for both light scatterings of sand and for more heavily normal mapped detailed elements. One thing we ended up doing to help comfort issues was a 'reverse detail map' to lower the effect of high contrast normal maps of sand just as you were running over them. This helped reduce high speed optic flow which caused some players with strobing sensitivity to have comfort issues.