In one embodiment, a method for rendering objects within an operating system includes receiving multiple data structures from applications executing on the operating system. Each data structure includes a declarative definition of one or more objects within a volumetric space to be displayed to a user of the operating system. The operating system can generate a render graph that includes the declarative definition of each data structure and can cause images of the objects associated with each data structure to be rendered based on the render graph and a pose of the user relative to the volumetric space.