First of all, understand the matrix multiplication formula in mathematics, in 3 rows, 2 columns * 2 rows? The number of columns, that is, the number of columns in the first matrix and the number of rows in the second matrix must be equal.

Please look at the chart:

Next, the four transformation principles of scaling, translation, stretching and rotation are explained. In three-dimensional space, different results can be obtained by constantly changing the light source under the illumination of the light source.

Only the position of the light source of the matrix is transformed, the light source is enlarged and reduced, and then the scaled image is projected. See chart:

Only the data of the position of the third column of the matrix is transformed, and the translated image is obtained by projection. See chart:

Only the x or y position of the matrix is transformed, and the projection will get a stretched image. See chart:

Remember the formula first: