[12dreamz]

Hi folks,

recently got the Michael E. Helms book "Perspective Drawing - A step by step guide". Nearly through. Well, but I still don't know how to find that third vanishing point (for the parallel height lines). The usual perspective has two (width an depth) or one vp(s), both can be located by construction in the plan view of a perspective and are located on the horizon line, no problem.
But the third vp (height) would have to be constructed someway else. To make it easier on you I know the height vp would coincide with the station point in the plan/top view, but I still would'nt be able to tell its vertical distance from the observer. If anybody had an explanation or a pointer, I would be very grateful.

An example would be a scyscraper viewed from down below. the top plane of it would vanish to two vanishing points on the horizon line but we all know from experience the height lines of the scyscraper would vanish, too.
But that last vanishing point obviously doesn't reside on the horizon line.
I could just take my center of vision and determine a vertical distance between the center of vision and the third vanishing point for the height lines. But I can tell there would be distortion if I did that.

Oh, where are my manners? Greetings to all members.

[AndyT]

Just some thoughts. Hope it's not too late.

In two point perspective you look at a point on the eye level. There you can move up and down and closer to the object or further away.
In 3 point perspective you can also look up and down ... tilt your head.
So it's up to you where you put the 3rd VP I guess.
The most extreme situation would be single point perspective again:
http://www.wetcanvas.com/ArtSchool/Toolbox/LearningHowToDraw/Perspective2/index.html

It's where your new horizontal line (not the same as the eye level) crosses the center of vision.

Hope I'm right!?

You can also use a little trick to avoid distortion.
Move the VPs of lines with too much distortion further out of the image.
The height lines will then be parallel and make the object read ok.
You have to experiment to get a good effect though afaik.
It can't be constructed.

If you don't understand it as text I can try to illustrate it! Should I?
_________________
http://www.conceptworld.org

[Capt. Fred]

Straight off the top of my head, I would have thought that the 'vertical CP' would be vertically above and below you, since that is where towering buildings converge (above), looking down is the same.

..though I'm guessing you're gonna need to curve the lines - that's what I see.

I don't know basically. But that was my guess.

[12dreamz]

Thanks for answering( and thinking alongwith me), already thought the thread was forgotten.

AndyT : I've understood quite well. Tells me both of you were able to put some sense into my post. I agree that putting the 3rd vp farther away would result in parallel vertical lines but that's not my aim. Actually I was afraid someone could say it's inconstructable, well I guess I'll have to abide by it.


Capt. Fred : I guess I know what you mean about curved lines but problem is the viewer doesn't accept it in a drawing or rather does accept it as being hyperreal. That CAN be a good thing but is rather seldom required.
As far as the location of the 3rd vp goes I'm absolutely with you, question is and unfortunately still is how FAR below and above.


So, I'll have to trial and error again, sigh.