Photogrammetry is the science of making 3D measurements from 2D photos. Photogrammetry is often used to make 3D maps and object on maps like buildings, it’s also used to make 3D models for animations, video games, and movies. In order to make one you need to take a lot of overlapping photos of the object you want to capture. Then you need to put the photos into software that uses the over lapping parts of the photos in order to find the position of the camera relative to the subject. Once the software knows where the photos where taken from it makes a rough 3D point cloud from measurements it took from the photos. Next the software makes a dense point cloud with more detailed measurements. Once the software has a dense point cloud it makes a mesh which can be used in a game, map, or movie. The software can also generate textures for the models using the same method.
I think its cool that you can take 2D photos and make a 3D model.
^Here are some that I made^ The link is for a test game that I made from one of my scans. (controls) W.A.S.D to walk, and mouse to look. To run the game unzip the folder and double click on the .exe (only works on windows)