[pierre]

I've noticed an interest in perspective construction techniques. I myself tend to see the indirect method very "artist unfriendly" as opposed to the "direct" perspective construction method which I personally feel more suitable, at least for an artist approach where quick rendering often is cruical and where you don't have to rely on projection drawings, simply on actual, desirable and/or approximate measurements.

The direct method works fine, at least for me, but that is only a personal opinion.

I made some personal notes on the direct technique, just scratching the surface. They allow for unlimited amounts of vanishing points if so desired.
1
2
3


If anyone is interested in a more thorough explanation on them, let me know.

[ October 17, 2001: Message edited by: pierre ]

[ October 17, 2001: Message edited by: pierre ]

[Icannon]

wow. neat stuff, pierre. thanks.

[edible snowman]

i really wish i could tell what is going on in those because it looks really useful.

[aquamire]

*blink blink* Ow, my head hurts. You sure that isnt Op-art not perspective? Uhh, I think I need to finish reading this book on the basics of perspective first, eheh.. you seem to know to much, Mr. Pierre.

[::Dino::]

Both the second and third examples are great. I'm having trouble understanding the first. It would help if you would add a legend/key explaining the lettered points like you had placed in two and three. If you wouldn't mind please do And thanks a lot for sharing Pierre

[Jaymo]

I'd like to add myself to Dino's request.

[digiGen]

Indeed, more information if you please

[pierre]

Picture no. 1 is a proof of the direct method. Brief explanation:

In order to construct the correct perspective image of e.g. a horizontal line, that forms an arbitrary angle with the picture plane, you need to know

1. Its vanishing point
2. Its length inorder to get its perspective length

pic 1 shows the horizontal plane, the eye, the picture plane with the horizontal plane, the eye normal N, and AB1, a line which forms an arbitrary angle v with the picture plane.

you get the vanishing point of the line if you draw a parallell line, from the eye, along the AB1 towards the horizon. The angle with this parallell line is the as with the ground line v.

Inorder to directly being able to construct the vanishing point on the the picture plane - the paper - you rotate the eye down(the distance from your eye to the picture plane, which can be actually any lenght, depending on the "camera lens you wish to have") with the horizon as a rotation center up or down, depending on your needs.

From D(the distance) you draw a horizontal line and a line that forms the angle v with the newly drawn horizontal line that runs through D. It cuts through the horizon at point VR (vanishing point right).

So far you have constructed the vanishing point to the line AB1. Inorder to be able to correctly cut through AVR the perspective length of AB1, you rotate DVR down to the horizon with VR as a rotation center. That way you will obtain the point SR (stretching point right) which is the stretching point for all the lines to VR. You now take the real length AB1 and rotate it down to the object-foundation-line, to the side of its directin, with A as a rotation center. You so get point B2. You then connect B2 with SR
so that B2SR cuts through the line AVR in the point B, which is the correct perspective length of the line.

(B2B1A forms a adekvate legged triangle, so does SR-the eye-VR, the legs between both triangle are parallell, therefor SR is a vanishing point for B2B1.)

This was just very brief basics. But knowing this you are able to construct a point in space, with what kind of light you want wherever you want with just measurements and wishes of such.

[ October 18, 2001: Message edited by: pierre ]


[ October 18, 2001: Message edited by: pierre ]

[Ben Barker]

X <----- Your post


O <----- My Head

[morphgfx]

wait... let me thing about this for a few seconds...

[Jaymo]

Well, this may sound a little stupid, but I was wondering how to best deal with this method or other vanishing-point-related techniques if the VPs are far off your canvas?

[::Dino::]

Wow, very helpful stuff Pierre...Thank you. Systems for finding measuring points have held my interest for some time. The proof explains so much.

Question: Would you ever use the setup shown in the proof to construct objects in space(if yes, would you mind demonstrating) or is it only a demonstration and/or explaination of the measuring systems used in examples two and three?

Thanks again, Pierre

[ October 18, 2001: Message edited by: ::Dino:: ]

[digiGen]

Pierre, can you recommend any books on this subject? Direct perspective..

Your explanations may make sense, but I need to digest this stuff in small bites to fully understand it.
A book would be great for that.

Or a step-by-step tutorial...

[Shinja D]

My book suggestions would be:

1. "Basic Perspective Drawing 3rd Edition" by John Montague
2. "Perspective for Artists" by Rex Vicat Cole
3. "Creative Perspective for Artists and Illustrators" by Ernest W. Watson

That would work as buying order, too. When you want to learn perspective from scratch #1 is as good as it is expensive (check out the sample pages at amazon.com)

- Shinja