Uncomfortable's Advice from /r/ArtFundamentals

Circles/Squares in Perspective

https://www.reddit.com/r/ArtFundamentals/comments/sqmja0/circlessquares_in_perspective/

2022-02-12 08:07

Xybb

So here's a problem I can't work out, I just don't understand how it works. Having redrawn it multiples times on different occasions and I always get the same result. Can someone explain to me, why the center of the square is at the red dot and not the blue dot?

The minor axis (vertical turquoise line) should be going through the center of the circle and as such through the center of the square. Why is that not the case? I've even done some renders, same thing happens.

Edit: Not quite (see the overdraw of my render in the comments), the minor axis no longer aligns with the center of the ellipse. For the cylinder challenge it is advised, that you use the minor axis as a guide. Apparently I was wrong in assuming that the minor axis always aligns with the center of the encompassing box?)

https://preview.redd.it/qzmvi55t0dh81.png?width=1541&format=png&auto=webp&v=enabled&s=7b310da9743a61067b4d03f18b48c0ab412382e5

If someone has got an explanation you'd be making my day.

Edit 2: Forgot you couldn't add images in the comments :D

https://preview.redd.it/cmsjx40y5dh81.png?width=920&format=png&auto=webp&v=enabled&s=0795f0c261e795498a25655c91dbf44f532a466b

So I think the assumption that the minor axis points at the vanishing point is incorrect (inaccurate)? I am pretty sure even Scott Robertson mentions it in his book How to Draw, unfortunately I currently don't have access to it to read it again.

Uncomfortable

2022-02-13 16:18

So you are technically correct, but ultimately it comes down to this: it is more useful for learning to teach this concept that is not always correct, but is correct in many situations, and is close in others. The principle applies very well in 1 and 2 point perspective, but where it starts to erode is in 3 point perspective, and as those vanishing points get closer to the object on the page (resulting in more distortion and thus bigger gaps between this concept and what is actually correct). The thing is, if we were to worry about ensuring everything was 100% correct in each instance, we'd be stuck at the beginning for vastly longer, rather than pushing forwards with something that is largely "good enough".

Drawabox itself isn't a course in technical perspective, but rather one that focuses on developing an overall, more intuitive sense of 3D space. That said, as you noted yourself, even Scott Robertson (who is well regarded for his mastery of technical perspective) uses this approach because it's just far more effective, and the margins of error are basically not significant enough for people to notice in most drawings.

I know that answer doesn't actually rectify the situation, but for a deeper dive into what would actually be correct, that would be well beyond what I can provide.

Xybb

2022-02-14 21:18

Your answer is very much appreciated and helps a lot. My concern was that my understanding of the content was wrong because i assumed It was a rule that's Set in stone. Equipped with that knowledge i now know better where eyeballing is Close enough and when constructing is in Order.

I was doubting my own Research and didnt find an answer to that contradicting information, so thanks again for Clearing that mystery