Why makehgtform creates 4x4 matrices? Why not 3x3?

I cannot found the answer on its description page. Why? This is so obvious??

Answer 1

[Mike Garrity]

Actually, I just put a post on the MATLAB Graphics blog which tells the story of why they're 4x4 matrices. You can check it out here.

http://blogs.mathworks.com/graphics/2015/09/28/homogeneous-coordinates/

[Mr M.]

thanks, this makes sense, however it is strange that homogeneous coordinates are not mentioned in the original description page

Answer 2

[Thorsten]

Rotation and scaling transformation matrices only require three columns. But, in order to do translation, the matrices need to have at least four columns. This is why transformations are often 4x4 matrices. from http://www.tomdalling.com/blog/modern-opengl/explaining-homogenous-coordinates-and-projective-geometry/