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-   -   Basics 101: Class 2 - Foundation of Perspective (http://www.wetcanvas.com/forums/showthread.php?t=597782)

Pirou 07-15-2014 08:59 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
In the mean time, here is the Exercise 3 done just putting the principles in the back of my mind and using them to inform what I am actually seeing without completely measuring them out and making them line up exactly to a vanishing point on the horizon, as I couldn't even do that with a printout of the actual view. This was drawn from actually looking at the bookcase and the yoga blocks, not from looking at the photograph I took of them. I'm sure had I drawn from the photo it would be more accurate, but I'm trying to learn to draw from seeing things in actual life. It's easy to draw from a photograph because the transition from 3D to 2D has already been made for you. I don't know why it's so hard to do it in actual life. Anyway, here is my attempt. I only have 3 yoga blocks, so it's not 4 boxes, but maybe the books can count.


Pirou 07-15-2014 11:19 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
More perspective questions.

Okay, I have been examining the diagram that is supposed to go with Exercise 3, which is Figure D. This shows a cube with only one vanishing point, but more than 1 facet of the cube is visible. This should be drawn in 2-point perspective. If we were to stand this object up, it would not be square, and it would fall over.

The same situation is shown in the accompanying guest lecture which describes one point perspective as "all vertical lines are perpendicular...all horizontal lines are parallel, and...all diagonal lines intersect at the point on the horizon..." That is not correct. The lines described as horizontal would only be horizontal if the front facet were directly facing the viewer and was parallel to the viewer. As soon as the cube moves to the side or rotates so that more than one facet is seen, it becomes two-point perspective, as each of those facets is going to have its own vanishing point. Otherwise, it's not a square object. I think these descriptions and drawings are confusing to a learner. Can these posts be changed? I think they are presenting erroneous information.

sarajane554 07-16-2014 11:06 AM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Quote:

Originally Posted by Pirou
More perspective questions.

Okay, I have been examining the diagram that is supposed to go with Exercise 3, which is Figure D. This shows a cube with only one vanishing point, but more than 1 facet of the cube is visible. This should be drawn in 2-point perspective. If we were to stand this object up, it would not be square, and it would fall over.

The same situation is shown in the accompanying guest lecture which describes one point perspective as "all vertical lines are perpendicular...all horizontal lines are parallel, and...all diagonal lines intersect at the point on the horizon..." That is not correct. The lines described as horizontal would only be horizontal if the front facet were directly facing the viewer and was parallel to the viewer. As soon as the cube moves to the side or rotates so that more than one facet is seen, it becomes two-point perspective, as each of those facets is going to have its own vanishing point. Otherwise, it's not a square object. I think these descriptions and drawings are confusing to a learner. Can these posts be changed? I think they are presenting erroneous information.


Sorry for interjecting, but I had the same thought process that you expressed above when I was thinking about 1pp versus 2pp. But I do believe the posts you refer to are correct: If one of the cube's faces is directly facing the viewer (even if it is off to the side, not directly in front of the viewer) then it's 1pp. If one the the cube's edges is directly facing the viewer, then it is 2pp. And if one of the cube's corners is directly facing the viewer, then it's 3pp. Arnoud, is this way of thinking about the issue correct? Or maybe you can correct us both :-) Thanks.

sarajane554 07-16-2014 12:38 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Here, I think this drawing will illustrate my point:

The big box, we can all agree, should be drawn in 1pp as it is right in front of the little stick viewer. But then you see that if you take a slice off of the right side of this box, you get another box (the small, right most box), which is no longer straight in front of the viewer, but which still has a face facing the viewer and clearly is & should also be drawn in 1pp.


Pirou 07-16-2014 02:43 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Hi Sara, that's exactly what I was thinking. If the object faces the viewer squarely and directly in front - one vanishing point, one point perspective. As soon as you see the 2nd face - two vanishing points, two point perspective. I hope the posts can get changed to reflect that.

The little box you add, if added to the original box, is part of that one vanishing point perspective. As soon as you take away the original box, it becomes two-point perspective, unless the viewer goes and stands directly in front of its flat face. It would not be drawn in one point perspective if the viewer remains standing where you have drawn him and turns his head to look at it. He would not see any lines parallel to his own position from that perspective.

You can test it by putting a block to your side in the position indicated in your drawing. Neither face will display a horizontal line to view. The perspective changes even when we close one eye and open the other. It changes drastically when we turn our heads 45 degrees to look at the corner of a building instead of the face of one in front of us.

sarajane554 07-16-2014 03:06 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Oh, no I think I've not expressed myself well because what I meant to demonstrate was that the small box on the right is in 1pp (even if you delete the left hand portion, it would not change it from 1pp to 2pp). I guess it's the difference between sliding a box from side to side (which would not make it change to 2pp) and rotating the box (which would make it change to 2pp). I don't think the viewer turning his head changes the perspective. Only if the viewer were to walk around and view the object from another angle would the perspective change.

sarajane554 07-16-2014 03:12 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Another thing is this: according to your description, in order to use 1pp, you want to have the box facing the viewer, centered directly in front of the viewer. Why not also require that the box be centered on the horizon line. Does the fact that you can see the top or bottom of the box make you want to use another vanishing point for the vertical edges?

Pirou 07-16-2014 03:58 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Here are the pics. The camera is in exactly the same spot at the same distance. The only difference is that the large box has been removed and the camera has been turned to look at the box. (Not even all the way)





All the vertical edges would only be vertical if the object were at eye level. Above or below eye level changes the angle of the verticals that are not directly in front to diagonals. That's why if we stand at the top of the Empire State Building, the bottoms of the buildings below look smaller than the tops. I think most of the time we don't have to deal with this question because we are mostly drawing buildings at the same level that we are standing on and the distance to the top of the building is not great, so we draw the verticals as vertical although that's not quite what we see if we were to measure at an infinitesimal level. If we draw a skyscraper from below, however, we can't ignore that the horizontal lines converge towards a point at the top.

Pirou 07-16-2014 04:23 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Quote:

Originally Posted by sarajane554
Another thing is this: according to your description, in order to use 1pp, you want to have the box facing the viewer, centered directly in front of the viewer. Why not also require that the box be centered on the horizon line. Does the fact that you can see the top or bottom of the box make you want to use another vanishing point for the vertical edges?


Yes, if the scale were large enough for that difference to be noticeable.

arnoud3272 07-16-2014 05:44 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Kiran and Sara - Thorough discussion :thumbsup:.
But I have the feeling that you think too much :). Perspective is a formulaic convention, not a faithful description of the reality. It is a tool and all depends on how you use that tool. IF you choose to draw in 1PP, then the back and front edges do not converge, such is the convention. It distorts. But if you imagine the 2 VP's in 2PP too close together - for convenience - you get another unpleasant distortion.
You can use the perspective tool for two purposes: the most important here is to check what you drew for consistency. First draw, than check.
It can also be used for constructing from imagination, e.g. by architects.

Kiran
- Cameras - except the very high end class, and then only if you know how to adjust - always distort the perspective. So of course you could not analyze your photo satisfactorily.

Returning to the lesson of this class, First draw, than check, you did very well; only at box A you lost you concentration.



Well done in this class, please move on to class 3 :thumbsup:

Pirou 07-16-2014 06:16 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Ah, yes! Box A - all over the place! That was the third/most tired box.

May I complete the remainder of the exercises in this lesson before moving on to the next? I'm not in a hurry and, as you may have guessed, kind of need to be thorough to really understand what I'm doing.

Pirou 07-16-2014 07:24 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Okay, I combined Exercise 3 (Draw tissue box and/or table, plus draw a straight back chair changing the eye level) and the FINALLY Exercise (Apply 2- and 3-point perspective to subjects in exercise 4).

3 Table drawings (I don't have a straight chair):



Ref 1 - this one was difficult because of the lines of the bookcase in the background and in the carpet on the floor. In contrast to the bookcase, the top line of the table appeared to be sloping downward, but it really wasn't. Once I overcame that optical illusion, I started over for that one.

Pics taken after each drawing was completed. I drew the legs as if they were not warped as the actual table is.



Ref 2



Ref 3 - this one I drew in 3-point perspective, trying to make it as little noticeable as possible.



Okay, I feel better having completed the majority of the exercises...

sarajane554 07-16-2014 10:20 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Quote:

Originally Posted by Pirou
Yes, if the scale were large enough for that difference to be noticeable.


Well, can't the same be said regarding a box drawn in 1pp where you can see two sides at the same time :-)

Pirou 07-16-2014 11:34 PM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Quote:

Originally Posted by sarajane554
Well, can't the same be said regarding a box drawn in 1pp where you can see two sides at the same time :-)


I'm going to make some drawings and find out! My next day off is Friday. I'll try it then!

I'm finding all this investigation and questoning very helpful.

sarajane554 07-17-2014 09:39 AM

Re: Basics 101: Class 2 - Foundation of Perspective
 
Quote:

Originally Posted by Pirou
I'm going to make some drawings and find out! My next day off is Friday. I'll try it then!

I'm finding all this investigation and questoning very helpful.


Yea, me too, it's a good conversation. I'm thinking that, as Arnoud said, it's not an exact science but more of a tool to help us get things looking right.

1pp is really the same as 2pp, but with the second vanishing point so far off to the side that it's at "infinity" and you don't see the horizontal lines converging at all. So I think that when you observe something you want to draw, if the horizontals look close to being parallel, it is easier to draw it in 1pp (even if its face is not directly in front of you), rather than trying to do 2pp with a 2nd vanishing point 3 meters off the end of the page :lol:


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