In my opinion, that section of the video is a bit messy.
Before the segment he is talking about input, then he goes to "representation" but one is neither representation or input. The rotative phonograph is not a 3D model, it is a sequence of "classic 2d array of 3 RGB values" dam... he or you should just say a sequence of images perceived by our brains as a 3D object. But there is no real 3D data.
But keep in mind that the video is for deep learning, so that image differentiation between the frames helps to reconstruct a 3D space or object. That is what humans do and what they try to teach to the AI.
That input from a rotational object (among different others*) can thru some analysis, can provide you with a point cloud data.
Cloud point data is a raw collection of points in a 3D space. They have no meaning, they have no correlation until you give one. They can be collected by a laser scan, they can be deducted from an analysis of a rotational image sequence... aka video, among other methods.
But a point has no real dimension, it is a point, not a line, not a plane, not a volume.
A first approach to make sense of a data is to give volume to them. Then you use the point as a center of a ball, or a cube. That is where volumetric comes into place. In the video, there is a blob car, made of... blobs.
When the dots are connected... you can define a polygon. Remember that to get one segment of a line, you take 2 points. For a 3D polygon, you take 3 non-colinear points.
Humans model stuff by using the other methods, polygons, primitives, nurbs etc. By the way, the image the dude posted on the video is not 3D primitive, it is a nurb or bezier based model technique.
I did not saw it all. I was not impressed.
The image of the cloud point data image you posted is... another classic 2d array of 3 RGB values... it is just a collection of pixels that our brain interprets as a... 3D bunny...
The same with the others. The "real" data is just raw data. Any image we see is a representation of that data.
Every node, on every type of modeling technique, is simply stored as a 3D coordinate as J.E writed. The notation may differ. Some prefer an XML notation
the, data, ofIt
Some can just use data as they want.
In Nurbs and Bezier modes, the nodes are not of the vertexes, they are nodes to control the geometry. This geometry is reinterpreted by the program every time you open the file again.
A simple example using a 2D primitive. This is how a circle can be written in SVG.
<circle cx="50" cy="50" r="40" fill="black" />
You only need to type what object it is, where is the center (x and y) and what is the radius. Now you have a circle that is redrawn by the application.
If you want to know specifics consult the documentation of the file format you want.
To understand how Nurbs and Bezier work, you can google the term to see some examples.