3D simply means 3 dimensional, the physical dimensions of the object (size). Any object having 3 dimensions i.e ., length, breadth/width and height is a 3D object. Practically everything around us is 3D as every object has the above 3 dimensions (thickness never absolute 0).
Notably, mostly the term 3D is used in 3D coordinates, 3D designing which deals with parametric or nonparametric designing, manufacturing technologies.
2D (0 thickness) and 1D (point object) are generally used to simplify the calculations in the real world.
An object is said to have 3 dimensions if it has a length breadth and a height. However, this definition is not useful if the shape is irregular or spherical. In such cases, a more useful property is 3D objects that have the volume or that they displace fluids. So next time when you have to identify a 3D object, ask yourself this question when immersed in a jar filled with water will the fluid overflow.
Note: No object in the real world has less than 3 dimensions. However, sometimes one of the dimensions is ignored. Example: Paper is considered 2D but in truth, the thickness of the paper is so small that it is ignored.
Differences Are Always There
2D animations are mainly flat and it feels like you are looking at a photograph. The main software to use for this is After Effects, Photoshop, and Adobe Animate.
Animation can be rotated and moved around like real objects. The animator uses advanced technology like the software tools mentioned above to create a world of animation for you. Here, along with the X-axis and the Y-axis, there is another called the Z-axis. This makes the viewer see the object closer or further away.
Aspects Of 3D Technology
To see 3D you need 2 eyes that each make a 2D view from a different angle. That makes perspective. What is more, your brain can measure things in 3 D and not just 2D. If you see a square on paper, you can tell it is 2 sided and the same length each side. If it is even slightly different on 2 sides, it is s rectangle and not square.
Now, when you see a cube with three-axis each the same length, you have measured the 3rd dimension. You can tell a car is 50 feet in front of you and not 40 or 100 because of this.
Some people can drive a car with one good eye. That is because they lost an eye after their brain has learned the world around them. Their (and your) brain learned a car is 18 by 6 feet and a road is 25 feet wide and a tree is 30 feet tall and a person is 5 feet tall etc.
Autonomous cars always use stereo technology to see 3d which means they use 2 cameras like we use 2 eyes to measure distance and position of things. That is because you need 2 eyes/cameras to get that third dimension in a computer since they can’t learn like a human baby does, what perspective means in just 2D.