So i remember watching this movie sometime in the mid 90’s im guessing it was around then also because there was some not-too-bad CGI.
it was set in the near future, the earth had become a dry and lifeless place, and exposure to the sun was very dangerous. the movie followed one family who were biologists/eco-terrorists, who would genetically manipulate plants to become incredibly fast growing and large. both the parents were played by french actors i think.
the first scene opens up with the feds raiding a house where the family had been renting, to find it inundated with plant-life, lots of fungi and spores etc…
the family is one the move and settle in a new town. thier daughter meets a local boy and they hit it off, at one point they are having sex in a hot spring as the sun comes up and he is badly burned. there was also a ton of softcore nudity in this movie.
at one point later in the movie both parents have altered their own genes so much that the mom transforms into a sentient cloud of bugs/spores capable of speech and some sort of healing power.
weird/awesome movie. any ideas would be hugely appreciated! thanks!