Some aspects pertain to ray data storage for ray tracing rendering. Attribute data for a first ray can be stored. To define a second ray, data defining such can comprise a reference to the first ray (in one example) and attribute source information indicative of shared attributes between the first and second rays. The attribute source information can be shared among many rays, and can be selected based on ray type. Definition data for unshared attributes can be explicit with the second ray. A plurality of rays can reference one ray for shared attribute data. Referencing rays can be counted and decremented as referencing rays complete. Shared attributes can be indicated with masks. Interface modules can service ray data read and write requests made by shaders, and shaders can explicitly reference attributes of rays, without using such interfacing modules. Data structures can be used as attribute sources without being associated with particular rays, and can be defined and selected as attribute data sources based on ray type.