The Double Negative (Dneg) team responsible for the stunning visual effects in the master director Christopher Nolan’s epic space saga Interstellar has turned science fiction into facts by providing new insights into the powerful effects of the infamous black holes.
Nolan and his VFX team, led by Paul Franklin (of the visual effects company Dneg), worked closely with astrophysicist Kip Thorne to create scientifically accurate images of the wormholes, black hole and stars and nebulae featured in the film. Their research eventually led to a paper, titled ‘Gravitational Lensing by Spinning Black Holes in Astrophysics’, and in the movie Interstellar, which has also been published recently in the Institute of Physics Publishing’s journal Classical and Quantum Gravity.
The team described an innovative computer code that was used to generate the movie’s iconic images of the wormhole, black hole and various celestial objects and explain how the code has led them to new science discoveries.
Using their code, the Interstellar team found that when a camera is close up to a rapidly spinning black hole, peculiar surfaces in space – known as caustics – create more than a dozen images of individual stars and of the thin, bright plane of the galaxy in which the black hole lives.
These multiple images are caused by the black hole dragging space into a whirling motion and stretching the caustics around itself many times. It showed portions of the accretion disk swinging up over the top and down under Gargantua’s shadow, and also in front of the shadow’s equator, producing an image of a split shadow that has become iconic for the movie.
In a press release, Double Negative’s James said: “To get rid of the flickering and produce realistically smooth pictures for the movie, we changed our code in a manner that has never been done before. Instead of tracing the paths of individual light rays using Einstein’s equations – one per pixel – we traced the distorted paths and shapes of light beams.”
Once the code, known as DNGR (Double Negative Gravitational Renderer) had been developed, the team realised they had created a tool that would be valuable to real-life scientific research.
