Nvidia’s RTXGI vs SSGI vs RTX (DXR) GI?!

Nvidia’s RTXGI is an amazing new global illumination technology, now introduced into Unreal Engine 4, that gives great results at very minimal computation costs. Eventually RTXGI can / will work in conjunction with UE4’s native Screen Space Global Illumination (SSGI), but right now this gives us a an opportunity to compare the pros, cons, and trade-offs of the two technologies -- and then compare them alongside “true“ ray-tracing global illumination via DirectX Ray-Tracing (DXR) global illumination, using a