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View Full Version : 3 point perspective: where is the cone of vision & other questions... please help!

mMark
09-26-2010, 02:06 AM
please see attached image of one 3 point perspective.

http://forums.cgsociety.org/attachment.php?attachmentid=156565



I have the below basic questions:

Question A:
where is the cone of vision?
- In one point and two point perspective, since the picture plane is perpendicular to the ground plane as we look straight ahead, we can easily identify the cone of vision by making a 60 degree cone start from the eye. please see from the attached image whether I have done the cone of vision right?


Question B:
where is the picture plane?
- Is it could be anywhere? As in perspective diagram we rotate the eye to the picture plane right?


Question C:
How do I know the hight of our eye?
- In one, two point perspective, we define the height of the eye by the distance between the bottom of picture plane and the horizon line. I just curious how to find the hight of the eye in 3 point perspective.


thanks so much for your help guys.

- mMark
Lunatique
09-27-2010, 06:12 AM
I think you might be going about it backwards. You first establish your composition and the layout of your scene with the chosen camera angle, and then you work out the perspective for your scene. You narrative idea or your goal for the image is what will determine all the details you are asking about, not the other way around.
mMark
09-29-2010, 01:22 AM
I think you might be going about it backwards. You first establish your composition and the layout of your scene with the chosen camera angle, and then you work out the perspective for your scene. You narrative idea or your goal for the image is what will determine all the details you are asking about, not the other way around.I understand your point Lunatique and I agree.

This is purly a perspective study, I just want to know and understand as much as I can on perspective, just don't want to have any questions in this area.
Quadart
09-29-2010, 03:46 AM
B-answer: The picture plane is always perpendicular to the line of sight, just like the image plane in a camera.

I would suggest that you read this:

http://handprint.com/HP/WCL/tech10.html

It is a thorough source and I’m sure it will answer most, if not all, of your questions concerning linear perspective. The link is also in the tutorials sticky above.
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