I started modelling some fishes last year, but did not finish any scene using them, so they are sort of abandoned… will see if I can think of any scene to make use of them.
Modelling was very easy starting from a cylinder, making some sections and scaling the loops, then extruding the eyes and fins. But the UV mapping was very difficult to get right, so I finally used a simple projection UV.
On the final test scenes, to add to the undersea effect, I added fog, media absorption, and many little bubbles scattered around. The reefs are just some overlapping heightfields.