Preserved Topic: Horizon and perspective stuff

A kwikass "How to extrude single point perspective" :



1: Horizon and vanishing point. (the lil X)



2: Make your shapes in the manner you feel most at home with.



3: Umm yah (tole ya this was kwik).
Notice that objects above the horizon point down, objects below point up.



4: Extrude, using the lines as a guide.



5: Fill shapes, remove guides.

Tada! =)

Below is an example of 2 point perspective, same deal, just 2 vanishing points. You can keep going, 5 point perspective is really weerd.



These images were stolen from Sijun before it went down.... the 8th or 9th time. teehee.


[This message has been edited by Weadah (edited 09-18-2001).]

I could understand 3 point perspective, but how would you do 5 point with only 3 dimensional objects...?

I didn't think that you could actaully do 4 and 5 point perspective, becuase I thought that the laws of optics and physics only allowed you to see a maximum of three bounding box sides (If you were to draw a box around hte outer extremities of your shape) at any given time.

Care to show us an example of 5 or 4 point perspective?




In the beginning, there was the word...and the word was 'God', although by the time it reached the other end of the phone line... the word was 'Gznd'

Not really. =)

Ummmm fish eye breaks into 4 point (at the cardinal headings N,S,E,W) and one at the circle origin.

And what happens when you have a cityscape where the buildings are all facing different directions.. you run off into some odd levels of perspective... and wide-angle lens distortions etc etc.....

You have to realise I guess that there are different ways to handle perspective, and horizons/VPs
Also how you determine where VPs are projected along a horizon. lalala

Do 1 and 2 point for a whiles... 3 point is another thing again.
Curvilinear (5 point perspective) is kinda scary and hard to get right.

Weadz ()

[This message has been edited by Weadah (edited 09-18-2001).]

nice weadz, you explained perspective well with those pics, cool!

Aaaahhh! This little tut, compliments of Weadah, has thrown me down the gauntlet of memories past.

I did a 4-point once -- once. I don't recall the actual subject, though. All I remember is having far too many lines to deal with. It got pretty nasty, maddening, mind warping. Paper, meet Mr. Eraser.

I was going to say more about this little lesson, but it was turning into a rant fit for Philosophy and other Silliness. :sigh: Digress.

Compliments of Weadah and Sijun it would seem...

Reminds me of high school... Basic Art I. But I actually remember that sort of thing from the Secret City hosted by Commander Mark.

hooray

[This message has been edited by Human Shield (edited 09-18-2001).]

Yay for forums not loading... hip hip.. oh wait, I already said hooray.

[This message has been edited by Human Shield (edited 09-18-2001).]

Ohh, oh! I just *love* playing with persective! 3 point perspective is perhaps one of my favorites, although I enjoy distorting it at the same time in order to simulate motion, the movement of your viewpoint through space at any velocity will cause perspective lines to actually bend, makes for some weird, but really cool looks. 3 point is familiar to all, just stand at an intersection where you can look right and left, and tilt your head back to look up at a building, there's a vanishing point up there too!

Take that same analogy and picture yourself floating in the air somewhere near that same building and you'll have 4 point perspective, one right and left, and one up and down. (OR grab a "Spiderman" comic, they use it all the time.)

One of the tricks to using perspective to achieve images that look and feel accurate is to have your points *very* far from each other, I used to draw on a big 8 foot dining table, and I had a horizin line scribed on it, about 10" in. I'd attach my paper to the board and use string to lead to my vanishing points at either end of the table.

If you want to follow this even further, here's an interesting little factoid, the lines really shouldn't be straight, instead they should be huge curves! (Your eye is generally round, no?) Stand and look at a fence from close-up, try and see it going off to the right and left at the same time. The points seem to angle to the horizon line to the right and the left at the same time, yet directly in front of you it's straight, isn't it? And the top of the fence is the same line! One big curve. Lots of fun to be had with perspective, if I can get my hands on a good enough digital camera I hope to start capturing some of my old portfolio for you guys, lots of strange distorted perspective pen & ink work in there.

Your pal, -doc-

This is the same basics I used for my little siggy, but I tried to work it without guides.

Seemed like the only way to go since I wanted it to twist, bulge and get narrower at the end.

Otherwise it would have ended up with a complete spiderweb of guidelines.



[This message has been edited by Nimraw (edited 09-18-2001).]

Slow down. I'm lost.
Let's take my desk clock example.
Now, in real life, this clock is sitting on my desk. My desk is approx. 24" below my eye level. The base of the clock is sitting flat on the desk, but the clock face is rotated up to point directly at my face. I think I now understand the drawing of perspective lines for the base, rectangular parts. Weadz pictures and explanation helped a lot. I also understand how I would draw the perspective lines for the clock face IF it was facing straight...but it is not.
WAIT! I think I've got it. As I'm writing this, I think I understand it. Is that my second vanishing point? One vanishing point for the base, on the horizon. The other vanishing point some large distance into the earth on a line from my eyes through the clock face??
This is so exciting. (Please bear with me. Seriously the last visual art class I ever took was in 8th grade. I'm full of ignorance.)
Second issue. I'm having difficulty reconciling the two vanishing points with regards to the clock face. I am not seeing it in my head.

And question to Doc. Curves? What kind of curves? How does one determine the arc of the curve? Does the subject matter?

Full of questions. New world...

mobrul




[This message has been edited by mobrul (edited 09-18-2001).]

Mobrul, it looks like that clock picture is only a one point perspective. The vanishing point for vertical lines would be infinitely far "up" on the picture, and the one for the hozontal lines would be infinitely far to the right or left. The only vanishing point you can use with that picture is the one for depth.

This 4-point perspective thing sounds interesting... how would you go about making sure your lines are curved correctly? I suppose, technically, you could have 6 points and do a full spherical view. I guess this is some of the stuff that Escher played around with to make his spherical reflection drawings.

HHHAAAAAAAA!!! VER GOOOOOOD! I now see in 4 perspective point! **bows to master**

::::izzay

Actually for his clock, the perspective would be in two points, since he has the face turned to him, and the base below his horizon. Slime's right in the the vanishing point would be high, high up...however another vanishing point would exist in almost the center of the clock face.

With that in mind, and part of the "sides" of tha clock face that you could see from that angle would look to decrease back toward that point, as well as toward the skyline vanishing point.

oooh Doc and Weadz crack out the arc of perspective ~bows~

Very tough concept to deal with, but if you think of a fish eye lens, you start to understand a bit. Basically the arc of perspective is determined by the width of the angle of the viewpoint, or the depth compared to the width of the "lens".

The best way to view this is to look at those cheesy "panoramic" photos from Kodak film now. If you view carefully, you'll see that your horizon line is flat, but all angular lines to the edges have a very subtle curve. Open up[ the angle even more (wider panorama) and the arc becomes even more noticeable. As for calculations, now that's just damned deep If you experiment with degrading arcs in perspective views, you'll find that you don't see the arcs as being "incorrect" as long as they degrade properly to the vanishing points in increasing, and decreasing increment swells. If the arc is more defined, the angles just seems more "spherical" when viewed, as though the scene is (steals it) reflected in a metal ball, or seen through a fish eye lens. Make the arcs more subtle, and the panoramic feel is established, make them flat, and simple perspective comes in.

Fun schtuff.

Now deal with differentiated angular objects on the same horizons..~ducks~

More More More.

Peter





ICQ:# 10237808

Dug this out of my stock photos -- fisheye.jpg.

Mobrul - You're getting it man for sure.. none of this comes right aways, just keep doing it. Something worth a try is to paint really quickly ... do lots of lil sketches from lots of different perspectives, trying to get the major chunks of information into your image.... spend about 30 mins on one then stop and start another.

Doc - Will that be soon do you think? I've been hanging to see some of your work for a long time. I cant be the only one. =)

Anyways ... Dont worry too much about getting tricky to begin with. Get comfortable with 1, 2 and 3 point. Get the basics down, keep it simple.

Dfferentiated angular objects on the same ....what?
Oooooh paint what you see, I geddit.. hehe


[This message has been edited by Weadah (edited 09-18-2001).]

This is great. I am going to have to disappear for a week. Big conference calling me away from the office. (Damn, just as I was getting excited...) I'll work some more on that clock and maybe some other stuff with all of the new knowledge I have.
Thanks to Weadah for all of your help, DG for your inspiration (it was your new sig, after all, that got me wanting to do this), and Doc for bringing us all together.
See you all next week.
mobrul

This is great stuff, all!

I'm not really an 'artist', per se. I just enjoy seeing what I (and others) can do with Photoshop. But this is the kind of thing that gets me excited about Photoshop! I can't wait to get home tonight and try this kinda thing out.

Even better, I've got the next four days off (today's my birthday, so I'm takin' a four-day weekend)!

Again, great stuff! This is why I love this place!

Does anyone have any examples of a five point perspective picture? I searched google but couldn't find anything...

Hey, I found a 5 point perspective drawing and a link to the site it's on.



The site is one for Scott McDaniel, and it's at www.scottmcdaniel.net

There's also great stuff on perspective there as well.

A direct link to the tut itself is here

Enjoy.



[This message has been edited by silence (edited 09-23-2001).]

http://www.worldofescher.com/

You *can* actually calculate the curves if you'd like, they're nothing more than big ellipses, (note, ellipses are *not* ovals, not the same thing at all!) Try this, set a glass on a table in front of you, and look at the shape the top of it makes, it should be a perfect ellipse, assuming the glass is round. Ellipses do not distrot by perspective, they always are what they are. (I guess a big enough ellipse would be distorted in other ways, but in the observable world it hardly ever is. Maybe a stadium might display this, look around. Really look!) What actually changes with ellipse in perspective is where the center of the circle might be, the shape remains the same.

Now, you can actually have more than one "horizon" line in the same image, if you had a cube that was tilted then the horizon could be below the "real" horizon when considered as a perspective excercise. Tilt it to the side and now you have an angled horizon. Here's another example pic, sorry about the size of these things, this could end up a painful thread to load! So be it.



Your pal, -doc-



[This message has been edited by DocOzone (edited 09-23-2001).]

uh oh! I think the lighting is off on that new block. Hehe I like the cartoony feel to the image. All this perspective stuff makes me want to put a straight edge up against my monitor...