Sijun Forums Forum Index
Log in to check your private messages
My Profile Search Who's Online Member List FAQ Register Login Sijun Forums Forum Index

Post new topic   Reply to topic
   Sijun Forums Forum Index >> Digital Art Discussion
View previous topic :: View next topic  
Author   Topic : "Perfect Square in perspective"
feral715
junior member


Member #
Joined: 17 Mar 2004
Posts: 3
Location: So Cal

PostPosted: Wed Mar 17, 2004 9:11 pm     Reply with quote
Anyone know how to figure the sides of a square in perspective? Assuming the square is not exactly in the middle of the vanishing points. To be more explicit: If I choose two vanishing points, draw the length of one of the sides, how do I determine the length of the other side? Not sure how to upload images so I'm just hoping it works.

Thanks




[http://www.socalartstudios.com/pages/hiddenlinks.htm][/img]
_________________
Don Flaws
http://www.donflaws.com
Back to top
View user's profile Send private message Visit poster's website
feral715
junior member


Member #
Joined: 17 Mar 2004
Posts: 3
Location: So Cal

PostPosted: Wed Mar 17, 2004 9:13 pm     Reply with quote
if you want to bother you can cut and paste the URL above to see the image. It's easier to show the question then to explain it.
thanks again
_________________
Don Flaws
http://www.donflaws.com
Back to top
View user's profile Send private message Visit poster's website
neff
member


Member #
Joined: 11 May 2002
Posts: 1444
Location: Germany

PostPosted: Thu Mar 18, 2004 5:08 am     Reply with quote
ehem... google?

http://www.google.de/search?q=perspective+square&ie=UTF-8&oe=UTF-8&hl=de&btnG=Google+Suche
_________________
*
Back to top
View user's profile Send private message Send e-mail Visit poster's website
dzou
junior member


Member #
Joined: 07 Mar 2004
Posts: 17

PostPosted: Mon Mar 22, 2004 2:05 pm     Reply with quote
if you think about it it will become obvious Smile





if the pic don't work goto

http://iquebec.ifrance.com/projet00/Image-13.jpg
Back to top
View user's profile Send private message
Kevinski
junior member


Member #
Joined: 01 Feb 2002
Posts: 4

PostPosted: Tue Mar 23, 2004 1:15 am     Reply with quote
dzou is correct..
this is the right perspective for your problem,
however, the reason that the square appears so distorted is down to the field of view .FOV(Roughly 100 degrees). Like a wide angle lens on a camera, your perspective lines are converging more rapidly.



Quantifying this effect is more difficult, but with your center viewpoint, extending your VP's apart will bring your FOV down to a more natural look without moving the central position of the square.

good luck.
Back to top
View user's profile Send private message
DJorgensen
member


Member #
Joined: 26 Jun 2003
Posts: 147
Location: Edmonton, Canada

PostPosted: Tue Mar 23, 2004 9:33 am     Reply with quote
Oh wow! I never noticed that... It makes it seem so simple now Embarassed

Great question feral715!
_________________
Back to top
View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
jfrancis
member


Member #
Joined: 08 Aug 2003
Posts: 442
Location: Los Angeles

PostPosted: Tue Mar 23, 2004 4:40 pm     Reply with quote
Very interesting. I didn't think there was an optical solution other than to use instinct.

Now that I see what you're driving at, assuming I understand it, I think I can even slightly simplify it:

Connect the lower corner diagonally across the square through the upper corner and straight at the midpoint between the two VP's. Wherever the diagonal across the square intersects the known edge is the point where you need to draw the unknown edge.

Yes?
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Sijun Forums Forum Index -> Digital Art Discussion All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Powered by phpBB © 2005 phpBB Group