It has been 2 years and orthographic mode is still totally broken. The lighting is all messed up and unreal ain’t fixing it.
I could use your help. If you haven’t voted on the bug, you should: Unreal Engine Issues and Bug Tracker (UE-11026)
Now, from the looks of it, though, we may have to fix it ourselves (thank the open source gods that that is an option!) I took graphics programming in college and know a little bit, but am afraid to wade in alone. If there is anyone with some graphics background willing to pair program on this one, let me know.
If you don’t have coding background you can still help by finding clues as to what is wrong. There are many obvious issues. Here is the basic rundown:
Shadow artifacts seem to be dependent on the angle the surface is to the camera. Occasionally shadow smears will show up on objects around the player. The problem affects all light sources in 4.15.
These clues lead my to believe that it is an issue in the GPU code for lighting. They may still be treading light sources in a perspective way instead of an orthographic way.