ELI5: Explain Like I'm 5

Homogeneous coordinates

Homogeneous coordinates are a way to represent points in space that makes it easier to do calculations and transformations. Think of it like playing with different shapes and toys, like Legos or blocks. Each block or piece has a specific location and orientation, and we can move them around and change their positions using different tools.

With homogeneous coordinates, we're really just adding one more dimension to our toy box. Instead of just thinking about regular 2D or 3D space, we now have a fourth dimension called "w." This extra dimension helps us keep track of translations or movements in space, like moving a block from one position to another.

So, in order to represent points using homogeneous coordinates, we use a four-component vector: (x, y, z, w). The first three components (x, y, z) represent the position of the point in 3D space, just like with regular coordinates. But now we also need to include a value for w. This value can be anything we want, but it's usually set to 1.

So what's the point of having this extra dimension? Well, it allows us to perform certain operations more easily. For example, instead of doing complicated calculations to translate or rotate a point, we can use matrices to perform these transformations. Matrices are just a way of organizing data, and they're used a lot in mathematics and computer science. But using homogeneous coordinates makes it easier to work with matrices and do things like scaling, rotating or moving objects around in 3D space.

In short, homogeneous coordinates are like having an extra tool in our toolbox that helps us manipulate objects in 3D space more easily. By adding an extra dimension and using four-component vectors, we can perform transformations and calculations more efficiently, making it easier to create and manipulate 3D graphics and visualizations.