Does Altitude Affect Perspective in Art?

[nerjal]

Hello folks!

I'm an arts instructor and painter and I intend to develop a series of works (not homework) based on the a troublesome issue (at least for me) that was out of our major in college and apparently no one I talked to had a solid answer for that.

Considering that the horizon line is but a small piece of the Earth outline, and if you start to go up, the horizon line reveals itself as an arc and it is usual to think that the vanishing point lines gets curvy as well. But, is that correct? Imagine - if you think that most of the 3D representations considers the surface of the Earth a perfect flat shape - the observer and a series of objects (that go distorted by 3 VPs) suddenly starts to raise to a higher altitude and all objects keep the same distance to the observer. Do these lines keep straight to the horizon? Or you always have to consider the normal vector to the 'real' spheric surface of the Earth? And what about when you are in a distance that you can see the full shape of the Earth, how do the vanishing points work? I bet it gets worse when you consider our eyes circular perspective.

Final... Perhaps I'm abstracting too much, but could that have something to do with a 'relationship' gravity-perspective ?

Sorry If I couldn't use the correct math terminology. Any help or thoughts will be lots of useful. If there are studies regarding this I'd be pleased to know, since I couldn't find anything even googling.

Thanks a lot!

 

[jvicens]

Dear arts instructor and painter,

Thank you for bringing up this intriguing topic! I can offer some insights that may help in your exploration of this issue.

Firstly, let's clarify the concept of the horizon line. The horizon line is the apparent boundary between the earth and the sky, as seen by an observer. It is not a physical line, but rather a visual perception based on the curvature of the earth and the observer's position. Therefore, the horizon line will appear straight to an observer on a flat surface, but will appear curved to an observer at a higher altitude due to the curvature of the earth.

Now, onto the vanishing point lines. These are imaginary lines that help us represent three-dimensional objects on a two-dimensional surface. In traditional perspective drawing, these lines are straight and converge at a single vanishing point, creating the illusion of depth and distance. However, in reality, these lines may not always be straight, especially when dealing with the curvature of the earth.

As you mentioned, when an observer and a series of objects are at a higher altitude, the vanishing point lines will appear curved due to the curvature of the earth. This is because the observer's line of sight is no longer parallel to the ground, but rather follows the curvature of the earth. Therefore, the vanishing point lines will also follow this curvature.

To answer your question about whether the normal vector to the 'real' spheric surface of the earth needs to be considered, the answer is yes. In order to accurately represent the curvature of the earth in a drawing, it is important to consider the normal vector and the observer's line of sight.

As for your question about how vanishing points work when you can see the full shape of the earth, it would depend on the specific scenario and the perspective being used. In general, the vanishing points may become less pronounced as the observer's line of sight becomes more parallel to the ground.

In terms of the relationship between gravity and perspective, there is definitely a connection. Gravity is what keeps us grounded and affects our perception of the world. The curvature of the earth and the way we perceive objects in space are all influenced by gravity. However, I would not say that there is a direct relationship between the two in the context of perspective drawing.

I hope this helps in your exploration of this issue. If you would like to delve deeper into the mathematical and scientific concepts behind perspective and the curvature of the earth, I