3d drawing: golden rule?

Question

im studing 3d pencle drawings basic shapes and i belive i have heard of a golden rule that applies to depth/distance and i dont understand it. can any one explain it and tell me who discoverd it?
say you draw a square and you want to make a cube well how much smaller should the far part of the cube be relitive to the square?

Answer 1

I think you have two ideas confused. The 'golden rule' has to do with a ratio that is considered the most esthetically pleasing. It Basically compares the with to the height or depth. It's used in alot of old architecture and paintings, including the Pantheon and the Mona Lisa. http://www.youtube.com/watch?v=2zWivbG0RIo
http://www.youtube.com/watch?v=7Cx9ApVus1g&feature=relatedThese video s try to explain it
The next part, deciding how much smaller the second part of the cube is depends on your view point, and a little bit of problem solving using what ever type of perspective your drawing is in. It would be very hard to describe it effectively, your better off asking a teacher to show you (or someone you know who understands perspective.

Answer 2

It depends on the relative distance from the cube to the viewer. If the viewer was a few inches from the cube, the far end would appear to be much relatively smaller than if the viewer were farther from the front surface.

The phenomenon is called "foreshortening."

Think about this example. If someone stood several yards away from you and pointed his finger at you, his finger would seem relatively small to the rest of his body. (fingers ARE, after all, only small parts of the entire body)

But if the person stood, only a couple of feet away and pointed his finger, directly at you, that same finger would loom large in your vision, because it would almost touch your eye, while the body seems relatively small, compared.

So, there'd be no "golden rule" applied, every time, to drawing a cube. It will ALWAYS depend on how big the cube is and how close the artist is to the cube.

Try it yourself with a wire frame cube made from drinking straws, held together with lumps of clay. Set the cube a foot from your face and look at the front of the cube and then compare it with the back. Then set the cube across the room and compare the "size" of the front and back sides of the cube.

Answer 3

I believe you are talking about the "golden mean" which has been used in Greek architecture and later in the composition of drawings, paintings, and sculpture.

About the cube question, to the best of my knowledge, the far part of the cube is the exact same size as the first and second sides. (We actually can't see the other two sides, but if they weren't equidistant, it wouldn't be a cube.) The foreshortening part depends on the viewer's line of perspective.

Answer 4

Heck yeah! I am armed with my dictionary, and a general disdain for people who spell words incorrectly. Just kidding, I hate it when people do that. If the question has nothing to do with spelling, don't correct it.