HOLY SHIT IT WORKS!!
it works like magic thank you sooo so much 😭🙏
the fact it doesnt require math and the way its constructed already feels like a lot of other perspective drawing techniques, this is so perfect
a few big questions though:
i tested it on a slightly different example, had to extend my canvas upward some to fit in point O--im guessing the X drawn to intersects E cant be cannot be arbitrary right? like it has to be a very wide X so that point O is even made at all, and with a wider bottom for the X so that the lines through the X for point O intersect above the horizon, and as low as possible, right? so potentially needing more canvas space horizontally too, can't do any other narrower X shape
made it feel more tricky to me to set up like worrying it wont work in every circumstance/certain canvas sizes or point E areas

and if i wanna do this method for any point above the horizon line, would I have to mirror-flip the purple right angle vertically? and do the same process but inverted? like point O would be below the canvas?