Uncomfortable

2022-09-23 19:42

You are correct - what's presented in the video is an oversimplification which is more correct when the vanishing point moving is in the center of the frame, and less so as it moves out further to the sides. The actual math behind the rotation is complicated (although a little easier to understand when looking at the whole model from the top, as shown here), but I was concerned that digging into it would cause a lot more anxiety and panic than was necessary. There are definitely a number of places where we use such simplifications to simply avoid getting sucked down certain rabbit holes.

Another such simplification would be the use of ellipses to represent circles in 3D space - it works well in 1 and 2 point perspective, but as we get further into 3 point perspective situations with more and more distortion, it tends to fall apart. Of course, such circumstances are rare and the ellipse simplification still works well enough overall to be an extremely valuable tool.

All that said, I am working on the updated version of the boxes video, and I'm making a point to specifically not imply that the movement would be equal along the horizon line, though I still won't be getting into the specific math behind figuring it out accurately, as that is well beyond the intended scope of the course.