What the fuck.
Black circle looks more correct than green circle???
>>2317344
Well anon. It's impossible for us to tell without a context as we don't know what they are trying to do but if I had to make a guess based on just that picture I think my edit might help you understand.
>>2317354
that doesn't help at all sorry
I'm just watching Marshall vandruff's perspective drawing series and he's talking about drawing an circle in perspective, in which u don't simply connect the four axis points on the sides of a circle but apparently have to find the axis of the ellipses through vanishing point lines??? I don't understand it at all.
>>2317356
I just watched two youTube videos with him. Sounds like he's the type who like to over complicate stuff to fill out big books that he can then sell through his teaching. I think American professors are credited and paid by the amount of pages they produce.
I honestly don't understand why you would want anyone to try and teach you something you already know but just need practice in. Being able to draw them properly will come as you train your observation skills.
Scott Robertson's "How to Draw" is a good reference for drawing ellipses in perspective. Made a lot more sense to me than these figures.
>>2317362
>Being able to draw them properly will come as you train your observation skills.
Yeah, I guess, but actually just learning the mechanics of perspective is faster and more applicable. Very confusing at first, but its better than just grinding studies until you eventually figure it out.
>>2317375
I'll teach you a neat trick then. If you are drawing the image digitally the flip it horizontally, if traditionally then use a mirror. You will immediately spot all the flaws you were struggling with prior. It's just how our brain works. In the case of circles you will see where it'll need correction and how much.
>>2317344
>tfw when scrubs on /ic/ don't know what a thrust line is.
stay pleb, anons
>>2317389
explain
what the FUCK
>>2317389
>Must be about calculate vectors in order to draw a circle in perspective. Posted on /ic/
I think you are the plebeian here, anon.
>>2317395
Do you have zero spacial understanding? How is this possible?
>>2317396
>It must be about strugglin' with English for you
Care to try again, amigo?
Stay stupid, /ic/.
>>2317344
So... simply drawing an ellipse perpendicular to the axis line is not an accurate way to draw a circle in perspective?
It looks like he's trying to extrapolate based on an octagon in perspective or something.
How does one determines this points?
>>2317639
I mean, I can see it's the intersection between corner diagonals and perspective lines, but how to get perspective lines to cross at the correct point
>>2317639
>>2317640
I suck at explaining things without actually showing the whole process, but I will do my best.
First you make the drawing without perspective, next to the one with perspective, like I did in this pic, just a simple square with a circle inside, then you make the axes of the square, now on the point where the axes meet the circle on the drawing with no perspective you draw a horizontal line until it reach the end of the square (the lines in red on my drawing), on the point where the red lines meet the side of the square on perspective you make a line going towards your vanishing point and it is done, the point where those lines (in red again) meet the axis on the square on perspective you have the points you asked for.
If you can not understand what I said, let me know I can make a step by step tutorial, probably tomorrow, but I will.
>>2317655
I must add that this is a ancient technique architects used when they needed to draw circles in perspective with extreme accuracy, now days I bet most people just "guess" where the points are. But it still a great method, if you use it the circle will be more precise, and with time, you will develop the skill to draw without it.
>>2317639
>>2317640
the red lines go to r vp which the circle is on. They intersect with the circle where the radius is 1, so the ellipsis has to be known. So from the r vp through the point where the 45 angle is one radius. That creates four points on the ellipsis where a perfect square can be found. This is just the same triangle as the four green points, only spun.
The guy above made it incredibly obtuse. You only need the ellipse and it's plane to draw new lines from the vanishing point through the point where the diagonal intersects with the ellipse. This does not work if you want to spin the square.
>>2317658
>The guy above made it incredibly obtuse.
Strangely I actually understood his.
>You only need the ellipse and it's plane to draw new lines from the vanishing point through the point where the diagonal intersects with the ellipse.
Has anyone ever been so far even as to go...
>>2317395
What's the problem?
The minor axis aligns with the vanishing point as always.
The major axis is along the centre of the flat ellipse, where you could perfectly fold it in half. But since this is not a flat ellipse but rather a perfect circle drawn in perspective, the centre point of the circle is 'off centre' as far as the flat ellipse goes, because it moves towards the vanishing point. So one half of the circle in perspective will appear smaller than the other, unlike the flat ellipse where they're both even. It's the same way the farthest edge of the surrounding square is 'shorter' than the closest edge, as it moves towards the vanishing point - but taken as a 3D object, both edges are the same length, they're just being presented in perspective.
The true centre of the circle in perspective is found via that surrounding square, with a cross placed through it, making their converging point the centre point of the square and circle in perspective.
>>2317724
>Strangely I actually understood his.
Glad I could help.
>all these nerds trying to get it just perfect
Just eyeball it holy kek
>>2317602
There's nothing wrong with that sentence, dumbass. It's just you who struggle with reading things in context.
>>2317978
Eyeballing it becomes a hell of a lot easier once you understand the theory behind it.
>>2317356
Jesus, what a horrible way to learn.
Just eyeball it.
Drawing from the shoulder helps, too.
>>2317362
What the fuck are you talking about, if anything he makes it simple
>>2319548
I'm not sure if you guys are trolling, since there apparently are somebody teaching in this stuff but how can you just not see if it got the right perspective? That's the part I find confusing.
>>2317984
>about calculate vectors
not only is that grammatically incorrect, it also had nothing to do with the thrust line of an ellipse.
>>2319532
>just feel it out man!
>Drawing from the shoulder helps, too.
Are you just throwing out random advice at this point? How is drawing from the shoulder related to understanding how to draw a circle in perspective?
That said...
>>2317356
I haven't seen the video so I can't say for sure, but why not just draw a square within the perspective you want the ellipses to be with vanishing points and all that, and then draw the ellipses within the square? The center point of the circle will still be the center point of the square (if you draw the x between the corners). The minor axis will always go through this center point I'm pretty sure.
