This picture shows three objects rendered with two different methods. On the left is "standard" rendering, which uses vanishing point perspective. On the left is parallel perspective, which is what Furcadia uses. I've added the pink lines to help accentuate the difference.


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Understanding the different kinds of perspective is well worth the effort. If you're new to this side of art, take it slow. I promise it will make sense to you soon enough, and there are many ways in which it'll pay off.

Vanishing Point and Parallel are two different kinds of perspective.

Vanishing point perspective is what our eyes literally report, and what cameras pick up in photos. The sides of a cube appear to be trapezoids (a trapezoid is any triangle with a point cut off). In Vanishing Point Perspective, parallel lines in real life appear to converge (come together if extended very very far).

Throughout history, artists have made pictures with one, two, and three vanishing points. Natural human vision sometimes seems to have none if you're looking dead ahead at something close to you. The convergence of parallel lines is there, it's just subtler.

If you wanted to, you could make a picture with dozens of vanishing points. If you want to get elements such as a table, a refrigerator, and a window to be visually convincing in a sketch made without reference, they should all use the same vanishing points. Conversely, if you want to make a picture that's somewhat unsettling, you can make them use different vanishing points.

Technically, human vision has no vanishing points-- it's actually going radially, with infinite vanishing points all around the edge of a circle. When you look at something that's a rectangular prism, such as a box, though, you just happen to notice three directions of convergence. So, for convenience, we can sketch as if there were only three.

Where vanishing points should theoretically be is constantly changing depending on exactly where you're looking. It's significant to note that vanishing point perspective requires a "me" to be "the viewer"-- it is innately egocentric. Effectively navigating around in the 3D world using an eyeball takes at least an intuitive sense of your location.

Artists tend to depict vanishing point lines using a ruler. Authentic natural human vision doesn't really have straight lines of convergence, it actually has slightly curved lines. Our brains are hard-wired to cancel this out so we don't notice this distortion so much. If you see a photo of something with grids on it, taken with a wide-angle camera lens, you're seeing the same effect.

Look upwards and the vertical vanishing point is overhead but look downwards and the vertical vanishing point is somewhere below you. If you're the sort of person who tends to look at your feet, buildings seem to loom in on you. We tend to intuitively associate angles with moods, and photographers can sometimes take advantage of this.

In Vanishing Point perspective, lengths/heights/widths are innaccurate and so are angles, but the inaccuracies are shared equally in the same way they are when we view an object.

Parallel perspective is what our brains construct out of what we see, as a sort of internal reference. This imaginary internal construct (a model in your brain) is technically more accurate regarding both the lengths of things and angles. In your mind, the sides of a square are the same length, and the corners are 90 degrees, even though what you see might appear to be several different lengths in perspective and larger or smaller than 90 degrees.

What you see, what you interpret, and what is really there, are three different things. Generally, what you interpret and what is really there tend to be the closest match. There are notable exceptions, however. The hardware in your brain that converts images with vanishing points into abstract geometry can sometimes be tricked by optical illusions. You're constantly correcting moving lines to form a mental picture of the static ones that are really there. THIS picture overloads your interpreter so that its static lines appear to move!

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Parallel perspective is also called an "isometric" view, meaning "equal measure", because lengths, heights, and widths remain accurate even though angles are inaccurate. A cube would be drawn with a square face, a parallelogram top and a paralellogram side, but every line has a length of 1 unit. (A "unit" could be 1 inch, or 3 centimeters or 8 feet, doesn't matter; pick something.)

In an engineer's technical isometric view, the height, width, and length of the item depicted can be measured and they are to-scale with one another. An isometric picture of a project such as a chair looks wrong in that it looks too deep, but the picture can be measured with a ruler to figure out how long the pieces of wood need to be.

"Chinese" or "Asian" perspective generally suggests what you would see if you were hovering in the air a bit. In Chinese "isometry", the widths are one scale and the depths are a consistently smaller proportional scale. The ratio is typically 2-to-1. For example, a cube might be 2 units wide but the line depicting depth is just 1 unit long.

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Whether the lines slant off to the left, or to the right, is a choice by the artist. Whether they slant steeply or slightly is also an aesthetic choice. Chinese perspective can get very awkward if you're trying to portray a first person view of things both to your left and right. If part of the picture uses one set of lines and part of it uses another, it can look awkward. If most of the picture is naturalistic (say, a forest of trees with several houses poking out of the mist), the artist might be able to get away with it.

Furcadia's perspective is a form of parallel perspective different from both engineering and Chinese isometric styles. In Furcadia, things are generally depicted along two sets of diagonal lines. A square on the floor looks like a diamond. A cube drawn in this perspective has a height of 1 unit and two sides each having a length of .85 units.

At the mundane scale, this is all pretty straight-forward. In the even-bigger-picture, though (that scale at which astronomers must deal with measurements) things get very wierd. Gravity at the mundane scale merely means 'things have weight'. Extremely large amounts of gravity cause lengths, heights, and widths to be smaller. Gravity also affects time-- a clock on a satellite runs faster than an identical clock at sea-level on earth. High speed, however, also affects time. The International Space Station is under less gravity but it's hurtling along so fast that its clocks go more slowly than the matching earth clocks. This is explained under the theory of General Relativity. What we intuitively perceive is only a small and very limited part of the accurate picture.

Similarly, parallel perspective such as you find in Chinese paintings is older than "Western" vanishing point perspective. Parallel perspective shouldn't be considered obsolete or primitive, though. Our natural perception of the world as having "vanishing points" may be more artistically pleasing. The less natural version that is parallel perspective, however, is more accurate.