DNeg created the prophecy stands as well as the glass spheres, which were shaded with a standard in-house glass shader that supported their in-house reflection placement tools. Extra layers were added to give the look of dust and dirt. 

Wrecking the Hall of Prophecy
Trying to rescue his uncle Sirius from Voldemort, Harry leads his friends into the Hall of Prophecy, a vast storeroom of magical predictions. The cavernous space was designed as a regular series of regimented shelves stretching in all directions. Each shelf bore a multitude of prophecy spheres, all holding a swirling mass of cloudy fluids. The set was created as a completely digital environment.

"We modeled a library of around 60 prophecy stands, all shaded to look like aged wood or corroded metal," Franklin explains. "We then developed a rule-based system for placing the spheres automatically on the shelves. All of the shelf layouts were managed with our proprietary asset management system which allows us to switch out geometry with placeholder nodes whilst working directly on the scene in Maya -- the hero geometry is then loaded at render time. The glass spheres were shaded with a standard in-house glass shader that supported our in-house reflection placement tools. Extra layers were added to the shader to give the look of dust and dirt, which was created with a combination of hand painted and procedural textures.

"The prophecy fluid was created with a pseudo-volumetric shader that mapped a complex, animating fractal noise texture through a series of closely nested concentric spheres like the layers in an onion's skin. The layers were offset-animated against each other, producing a three-dimensional swirling effect. Additional parameters created subtle glows and color gradients within the fluid. The render pipeline allowed all of the different qualities and layers of the prophecies to be broken out and carefully balanced in compositing. In the end, the shaders turned out to be so efficient that, with the exception of the most distant shelves, all of the prophecies were rendered with the hero look at all times."

For the confrontation between the children and the Death Eaters, a new rigid body dynamics system was used to animate hundreds of toppling shelves and smashing spheres. Created by software developer Peter Kyme, dnDynamite replaced Maya's native RBD solver. The tool was integrated with the dnAsset toolset, so that all of the objects within the Hall of Prophecy could be animated with a dynamics simulation. As animations were approved, they were cached out into a library that could be used to build up larger scenes.

In the Veil Room, Sirius confronts the Death Eaters, and the effect was created between 2D, 3D and practical effects. DNeg matchmoved the shot in 3D, rotoscoping Gary Oldman’s action onto a 3D stunt double. 

Initial animation by dynamics tds Trina Roy and Nici Hoyle was based on simple previsualization. Once the large-scale collapse of the shelves had been approved, the team switched on the spheres and prophecies, and made adjustments accordingly. Shattering spheres were created as separate simulations that were stored in a cache library, and then swapped out with the spheres at their impact points. Extra layers of pre-calculated falling debris, spheres and shards could then be dressed into the scenes to complete the animations.