Matrix is a very important element of all objects in three-dimensional world, scaling, and rotation, as well as the camera's control is reflected on the transformation matrix. The transform matrix is essentially a conversion relationship of the coordinate system. In addition to considering how to generate a transform matrix, it should pay more attention to the object of the transformation matrix, two coordinate systems A and B, from the transformation matrix MAB of the A to B. what is it then. The respective vectors of the actual constituent transformation matrix are the coordinate axes under the B coordinate system and the origin and point of the origin in the A coordinate system. This is very well understood, with MAB transform (0,0,0), (1, 0) (0, 1, 0) (0, 0) (0, 1) These special points are actually the variable array Composition vector and what is these points, actually the correspondence between the new coordinate system and the old coordinate system and the origin. This physical meaning is very important, typical application is the technology of BillBard. Knowing this physical meaning, we can also directly construct the transformation matrix between the two coordinate systems. This is different from the row vector or column vector, this is different, and it is different in D3D and OpenGL. It is the multiplication order of multiplication between the points and points. It is the left or right, this decision. The coordinate system corresponds to the row of the change matrix or column vector. There is also a collision detection and cone cutting algorithm for the physical meaning of the transform matrix.
