Birth of planet earth fulldome excerpt: the collision that formed the moon

Abstract

This visualization of a scientific simulation shows the giant impact that formed the Moon. 4.5 billion years ago, the early Earth collided with a Mars-sized rock called Theia , resulting in a spinning disk of lava and vaporized rock hotter than the surface of the sun. In this sequence, we see the first 24 hours of the 100-year process of our Moon s formation. This 1.1 million-point smoothed particle hydrodynamics model was 32 gigabytes and featured 492 data snapshots, which were interpolated by a factor of ten to play back smoothly on a 4K fulldome cinema screen. Using Houdini, special sprites used instanced spheres with a procedural falloff shader to face the hemispherical camera lens, to prevent intersection artifacts as particles evolved from solid to liquid to gas, and to avoid camera intersection. Other particles were surfaced as solids and liquids, and dynamic geometry lights allowed the emissive surfaces to illuminate diffuse surfaces. Processing and rendering a million translucent sprites was prohibitive on the AVL s 30-machine cluster, so the team used their custom Blurend pipeline to process imagery on the Blue Waters supercomputer. The shot was completed in Nuke, adding a Milky Way background and grading the mixing planet-forming material.