It's about taking known 2D graphics and UI approaches which were developed for CPUs and looking at effective rendering engine architectures doing the same using

It's about taking known 2D graphics and UI approaches which were developed for CPUs and looking at effective rendering engine architectures doing the same using GPUs. Terms such as "scene graph", "retained mode UI", etc. are those existing 2d graphics matter. So the approach, afaiu, is a data layout for the scene graph that basically is the more domain general concern of mapping graph e.g. Linked List, datastructures (that are CPU friendly) to array forms (GPU friendly) suitable for parallel treatment. Other GPU concerns, such as minimizing global traffic by local caching, and mapping thread groups to tiles. I found the idea of having the scene graph resident in GPU to be interesting. (note to author: "serialization" comes from networking roots of serializing a data structure for transmision over the net. So, definitely serial. /g)