Weta Workshop graphics engineer James Brown built a device in the shape of a ball that rotates and displays a flickering 3D image. The enthusiast was able to run Doom on it.
This isn’t classic Doom, but a variant called Voxel Doom, where each point of the game object is assigned a position in 3D space, just like the points of a custom-built volumetric display. The display isn’t actually 3D—it’s an illusion. “It’s like a holographic fan, but instead of spinning a 1D strip to create a 2D image, it spins a 2D panel to produce a 3D image,” explains James Brown.
Brown initially aimed for a rotation speed of 300 rpm to produce a smooth image, but found that higher speeds were needed to achieve the desired clarity, especially when filming.