im having a hard time trying to understand what is loomis trying to explain on this page, perhaps somebody in here could point me a website/video tutorial/book that can explain this concept more openly, all kind of help is appreciated!
He's illustrating a way you could use to think of the whole volume of objects in order to visualize them better and draw them foreshortened from any angle. Think of the whole cone, think of how it's surface goes around the circular base, instead of just thinking of a triangle from the side and a circle from the top/bottom. Did you read the text in the chapter? I remember him explaining it quite clearly.
I've tried to think of what he calls "cross sections" as "contours" that you could see on the surface of the form. You can also draw contours along the forms, in addition to ones that cross the forms.
If you took a knife to one of those forms and sliced it at a right angle to the surface, you'd get one of those cross sections.
I believe the idea is supposed to put the mind in a perceptual state of thinking of the form as more three dimensional, which should help you project it on to the 2D viewing plane (that of your paper).
I too am studying foreshortening right now, and it seems like one of the harder aspects to master.
If you can imagine a cylinder... like a can of spraypaint, or something... suspended in mid air... able to twist around in any direction, that's what he's saying--he's talking about any basic form like that.
Then he's asking you to go another step further and try to remember how those "slices" (or cross sections) would look when you turn the object any direction.
The exercise is to try and visualize what is happening with the cross sections, which should (theoretically) allow you to visualize and turn the simple objects in your mind.
When he's talking about "measurement", he's referring to a previous section of the book on proportion, where you measure lines against other lines in relation to one another. Thus, an outline isn't a measurement any more, because it isn't on the same plane as the paper.
Does that make sense?
From there, you just have to practice visualizing simple shapes (drawing them--naturally) in all positions and perspective, and then graduate up to harder, more complex shapes. Eventually everything should become second nature.
I say theoretically, because I've yet to dedicate the time to the exercise myself; but that's how it's explained. And I'm certain others have had success learning foreshortening practicing exercises like this. It's probably not this simple, but his explanation is just a simplified model of the problem of foreshortening. I think through practice, your mind should fill in the gaps.
HTH... now I gotta sit down and do the same
It's good to approach this combined with "Overlapping of forms" study.
The slices through the arm or contours of volumes seen from different angles take's on different and strange shapes sometimes but placing these shapes one onto or the other helps to create a foreshortened effect.
"Cannot determine the length" refers to the fact that sometimes you cannot trace a line from the form in front to the one in the back following one of the side planes, at some point they are behind volumes infront of them but you can find the "center" of these forms and having a feeling for the center of these volumes helps to align them properly and perhaps even accurately space them.
I grasped this when I did a study of a female nudie pic, the model was on all fours and her behind was towards the camera. Her behind got so big that you cannot see how it connects to her back, the contour of the legs and lower torso as a shape was concealing all of that, but knowing where the center of the pelvis is in space(kind of) makes it easy to align down the line with where you know the center of the waist and ribcage is, the problem and hard part is being able to draw a gesture line in 3d space like that without seeing allot.
Hogarth and Vilppu hammers on a valuable lesson with this, when these forms are almost in front of each other but not quite, where you can still see parts of the side or top surfaces as it goes to the farthest end, that you should not create overlap that “closes off” these shapes, the overlap should be kept open to help show that they are connected.
Last edited by George Abraham; June 12th, 2009 at 08:16 AM.
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