A mesh, texture or material held by the renderer. Once the handle is garbage collected the renderer frees the object as soon as no scene entry uses it: a mesh or material when no instance names it, a texture when no material does. A material's handle keeps the texture handles it uses.
Summary
Types
@type kind() :: :mesh | :texture | :material
@type t() :: %CauldronGPU.Handle{ id: pos_integer(), keeps: [t()], kind: kind(), ref: reference() }