For many, the Persistence of Vision raytracer has been the tool of choice; so it has been for me. See below a series of scenes that I did during the last years. I've not had much time for it, though; to see what can be achieved with more commitment, look at the works of Gilles Tran.
Petrified interstellar landscapes were an old obsession when, as a boy, I worked with oil on paper. So that's what I started with...
In 2000, when Audi started to make rather round shaped cars, it inspired me to take the last step to flying saucers Jetson-Style.
...and to reuse the saucers in a more mystic oceanworld setting.
Oceans... well, I thought there should be a more wild, foamy and unforgiving water representation than the swimming pool ripples offered by POVray water (also 3600x2700).
The sea, though unforgiving, gives excellent backgrounds for holiday moods with a luxury car (Thunderbird-Style, but never really built by Ford).
One of the greater challenges in raytracing is to create structures that are too complex to edit manually. This tree is an include file written by a Java program where natural growth is simulated, first starting with a twig and leaves, then in every step replacing leaves by twigs with leaves recursively and so forth; every twig or leaf is a single POVray object (which is a serious threat to performance), and it only looks really natural with radiosity turned on (again performance).
Trees can be generated at random. Here, also the sparse grass is generated to decorate a would-be boattail Jaguar.
Changing leaf colors to random red and yellow shades makes a good autumnal scene.
Cunim clouds work much like trees - they grow. So, the same principle is used here to grow clouds with Java. It is good to place ground fog underneath the clouds to spare the hassle with smooth lower boundaries. Here, the clouds are placed into a moonlit Orkney island scene with standing stones underneath a clear sky, thus suggesting a coming cold front from the west, just what Orkney is good at.
Talking about cunim clouds... There are more sophisticated algorithms in POVray to do that. See below for a thunderstorm.
Some of these images are links to bring up a full size picture or animated GIF. If anyone would like any of these images in a higher resolution, just email me and I can mail you one back.