SpaceEngine is excellent when it comes to customizing volumetric accretion disks, but the vast majority of users can't quite create the accretion disks seen by people like Ika Abuladze or myself. The document I will link below is not entirely finished, however with enough demand, I will finish the document so that others can create amazing black hole systems like I have done myself. I have created black holes and demonstrated my results on my channel.
Here is my video that I created called SINGULARITY: Venturing to the Craziest Black Holes in the Universe: https://youtu.be/JJ2qfjyyqa8
NEW VIDEO REGARDING THIS: https://youtu.be/9uHBStTDBlw