I read through this guide a while back and it is great. However it's fairly old now being from 2011 - are there any updated guides or explanations of what's changed since then?
I don't think all that much has changed except for the addition of meshlet and raytracing stages:
The 'descriptors are hard' article is a nice modern compagnion IMHO:
https://www.gfxstrand.net/faith/blog/2022/08/descriptors-are...
Also the D3D12 functional spec might be useful too:
The mesh shader pipeline isn't just an addition, it replaces several pieces of the old pipeline, like vertex shader, tesselation and geometry shaders. It's a pretty big departure. Though most engines don't use it yet I believe.
Does switching a UE5 game to lumen/nanite switch from essentially the "old pipeline" to the new mesh shader path, or do even the non-lumen/nanite modes use the mesh shaders?
Maybe optionally if the hardware supports it, but new UE5 features also work with older cards that already support compute shaders (a specialized pipeline which was introduced somewhat earlier) but no mesh shaders.