Relativistic raytracing

Would the image be very different for a rotating black hole?

Since they probably all rotate in nature.

This is very interesting, but way above my pay grade. Can someone explain how the resulting image reflects light traveling backwards in time?

Someone should implement this as a mod for RTX No Man Sky

Like 20-30 years ago there was a relativistic raytracer that was like POV-Ray, but with relativistic effects. Maybe named "backlight"?

How does this compare?

Edit: yeah this one: https://web.archive.org/web/20010604001305/http://www.anu.ed...