Raytracing From CUDA to SYCL 2020

How to convert a code from parallel C++ ray-tracing code to CUDA .
A walkthrough of
converting a code from parallel C++ ray-tracing code to CUDA, and the
work needed to make that CUDA code run on CPU using parallel for_each()
and then converted the code to SYCL 2020 via IntelĀ® DPC++.