自行编写一个简单的Vector3 向量类，至少需支持3D向量间的加减乘除操作，向量与标量浮点数的乘除操作，以及点乘(Dot)和叉积(Cross)以及归一化（Normalize）操作。（20 ）

(2) 自行编写一个Matrix4x4矩阵类，至少需要支持矩阵间加减操作，矩阵乘操作，矩阵单位化操作（Identity，即输出一个单位矩阵），转置操作，以及矩阵与3D向量相乘的操作。（请思考为何使用4x4的矩阵，并注意其与3D向量的相乘方式，实际上，我们需要将3D向量转为4D齐次表示形式，相乘后再转换回3D形式）-Write your own vector class Vector3 a simple, at least support the 3D vector operation between addition and subtraction, multiplication and division, vector and scalar floating-point multiplication and division operations, and the dot (Dot) and cross product (Cross) and normalized (Normalize) operation . (20 ) (2) write a Matrix4x4 own matrix class, at least between the support matrix addition and subtraction operations, matrix operations, matrix units of operation (Identity, the output of a unit matrix), the transpose operation, and the matrix and 3D vector multiplication operation. (Consider Why use 4x4 matrix, and note with the 3D vector multiplication method, in fact, we need to turn 3D 4D homogeneous vector representation, and then converted back to the 3D form of multiplying)