well it´s realy a small cubic room with the env mapping on some ground plates.
though it´s not realistic to fake the reflection of clouds and the desert indoors, i guess you will all get an imagination how it´s supposed to work.
i uploaded it into my free webspace, it has a bandwidth limitation of 1 GB per day. so please don´t download it a hundred times

size: 1.3 Mb (*.cab archive)
http://i.1asphost.com/gaardenier/demo.caball thank steempipe for makin this possible!