To switch between parallel and cross eyed, click the circle icon at the top of the screen. Use WASD to move around laterally, QE to move up and down, and use the up and down arrow keys to look up and down without moving. I was too lazy to program the stereoscopic effect with looking left and right, so I removed the left and right arrow keys.
@TheGoodGuy2000 made this renderer and BSP tree generator, and it is extremely fast, which allows for some cool things (like this stereoscopic renderer)! Also, I did not understand this renderer at all, so I couldn’t figure out was causing all of the missing faces. I even restarted from the original project to make sure I didn’t delete any blocks by accident, but the missing faces were still missing. But I think it still looks okay. (If you can fix this issue, please help lol.)