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Graphical projection - Wikipedia, the free encyclopedia
UO follows more closely to the Oblique projection method. You can see this in its most simple form in the floor tiles. Looking at the floor tiles, they look like a square tile that has been turned 45 degrees on the up axis (I use “UP” axis because Z and Y axis have both been used to define “UP”, so I use “UP” so that everyone can understand). Even though it's turned, it looks like you are looking straight down on it. All top surfaces that are parallel to the ground should mimic this in order to be true to the perspective. This means that if you have a circular fountain, the top of the fountain would be a perfect circle. I show this principle in the Red and Yellow Circles in the fountain picture below. You can see that by drawing a perfect circle, I can connect all four corners of the tile as well all edges with the yellow circle.
The problem is this: sometimes looking at things from this perspective isn't as aesthetically pleasing as if you "smudge" things a bit. If you look at the Green and Pink circles I’ve drawn, you can see that not only do they not follow the perspective as defined by the floor tiles, they don’t even follow the perspective of each other! The basin at the top is skewed more than the bottom basin. So this object doesn’t even adhere to its own perspective!
I still don’t think of this in terms of “right” and “wrong”. In game art, you’re always fighting the balance between aesthetics and technical accuracy. When you are creating artwork all in a 2D editor (photoshop, for example), it’s a lot easier to smudge the perspective because you don’t have to deal with other surfaces warping to compensate for you skewing the perspective a bit. With 3D, when we skew a surface, the other surfaces connected to it start reacting in ways that we don’t want, and that can get very tricky indeed.
What’s interesting is that the characters and environments in the Legacy UO do not use the same perspective, and we changed that slightly in UOKR so that they were a little closer to each other. In the Legacy client, the camera perspective on the environment art is about 45 degrees, give or take, but the players and creatures is closer to 20 or 30 degrees since you get a slightly more “head-on” look at the characters than you do the environment tiles.