Rendezvous with Rama

Update Sept 2020: see this new blog post for Rama v1.0!

I’ve recently been reading some of the old Sci-Fi masters, and I really fell in love with Arthur C. Clarke’s ‘Rendezvous with Rama’. I’ve read it twice now and was completely engrossed both times – I can’t recommend this book enough! I decided I wanted to recreate the titular spaceship using CGI, and have been working on it occasionally in my spare time over the past few years.

In case you haven’t read the novel, Rama is an ancient, hollow, cylindrical spacecraft that is 50 km long. It contains a breathable atmosphere and its rotation provides artificial gravity on its inner plains, which are divided by a Cylindrical Sea that runs all around Rama. There are several clusters of buildings on the Raman plains, which are dubbed cities (although they are deserted and apparently not inhabitable), as well as six light emitting strips that function as artificial suns.

There are many beautiful interpretations of Rama on the net, which can be found with a simple Google image search. My own version is a mishmash of elements from many of these illustrations plus my own imagination; I’ve also tried to be very faithful to the book’s description.

I decided to reproduce Rama using a physically based ray tracer called Luxrender, which is available for free. Luxrender is capable of reproducing such optical effects as asymmetric volumetric scattering (which causes sunsets to be red in the real world), helping to recreate Rama’s atmosphere.

The above image shows the 3D model of Rama, which consists of triangle meshes. Below I’ve posted a close-up of some of the buildings I made for the ‘cities’. These images are not final renders, but rather previews of the geometry of the scene – no textures, lighting, or atmospheric effects are included.

Finally, I’ve posted two actual renders of the current state of Rama below. These took a few days to create, due to the computational expense of simulating light scattering through the atmosphere!

I’ll be working more on Rama – there are still many details left to add – so there’ll be updates in the future.

Click on the images to see the full size versions.

Minor update (12 April 2017) – new image added with a few more details:

And here are the old images:

Second update (28 April 2017) – new image added with a few more details:

Previously, I introduced my recreation of the giant interstellar craft Rama from Arthur C. Clarke’s novel Rendezvous with Rama. Since then, I’ve worked on it a bit more, and I thought this was a good time to post the current state of things. I also wanted to thank everyone who responded to the first post!

Without further ado, here is the latest version of Rama:

(Click on the image to open the full size version in a new tab)

Update May 24th: I did another pass on Rama’s atmosphere and updated the image.

Overall, the image is now much darker and less saturated by Rama’s lighting, which is almost always directly in view. This changes the mood of the image to something that, I think, suits the novel better. I shrunk the buildings in the foreground, as they were far too big (they were about half a km tall). I also made the atmosphere thicker, so it’s more prominent. Finally, I painted some additional details on the ground texture and updated some of the building materials.

One thing I want to point out in particular is the way the atmosphere scatters light; in Rama, as in the Earth’s atmosphere, blue light is scattered more strongly than red light. This is called Rayleigh scattering, and it’s the reason why the sky is blue, and why the sun turns red at sunset. We can see this phenomenon at work if we turn down the lights a bit in Rama:

Rama’s “six linear suns” (of which we can see four) emit white light, i.e. light of all colors. The blue light now gets scattered, which we can see happening near the light sources; we see a diffuse blue glow of light that gets scattered every which way. The sources themselves look sort of orange, because the reddish/orange-ish light is not scattered as much, and travels unobstructed to our camera. The reflection we see toward the upper right corner is very orange, because this reflected light travels a longer path than the direct light, allowing more blue to be scattered out of it.

That’s it for now! For the next update, I’ll focus primarily on adding the ‘craters’ in the southern plains (Copernicus and its companions), as well as upgrading the look and feel of New York (the big island).