We usually hear the word pixel, but we cannot directly use the word pixel in a three-dimensional environment. Here we will see what Pixel, Hogel and Voxel are and why.
Pixel
The concept of pixel is used in a two-dimensional digital image or display device. The word pixel comes from picture element. That is, the smallest part of a picture (Element). The smallest part of an image or display that we can imagine, is the pixel of that image or display.
We all take pictures with mobile phones now. Or when buying a camera, we ask how many megapixels the camera has. A two megapixel camera means that the number of pixels of the photo taken with that camera will be two mega (2 million).
Same goes for display devices. If we imagine a 21-inch (Inch) computer or television monitor, then the number of smallest units in that monitor will be the pixels of that monitor. But the word pixel is not commonly used in the case of monitors. In the case of monitor or mobile display, we use the word resolution (Resolution) or dpi (dpi).
Hogel
So far we have been talking about 2D display. But in 2D display we don’t see the actual shape of the object, we only see the two dimensional part. And with the aim of eliminating this problem, three-dimensional displays or cameras have emerged in the last few decades. In fact, there are many different types of 3D displays or cameras, two categories (Holographic 3D System and Volumetric 3D System) are sufficient to discuss here.
The word Hogel comes from Holographic Element. The smallest part of a holographic plane like a pixel is called a Hogel. Each pixel contains light direction and intensity information, allowing us to see three-dimensional images or videos. Hogel can also be imagined as a light field.
Voxel
The smallest unit of a volumetric plane is called a voxel. But voxels have no absolute values, all are relative. Those who work in software like 3D Max or Maya will notice that the coordinates you draw are variable, not fixed.