1.绕Y轴旋转

Ry(θ) =  | cos(θ)   0   sin(θ) |
          |   0      1     0      |
          | -sin(θ)  0   cos(θ) |

P = | x |
    | y |
    | z |

P' = Ry(θ) * P

2.代码

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class mvp : MonoBehaviour
{
    private MeshRenderer rend;
    private Material mat;
    void Start()
    {
        rend = GetComponent<MeshRenderer>();
        mat = rend.material;
    }

    // Update is called once per frame
    void Update()
    {
        Matrix4x4 m4 = Camera.main.projectionMatrix * Camera.main.worldToCameraMatrix * transform.localToWorldMatrix;
        Matrix4x4 rotY = new Matrix4x4();
        rotY[0, 0] = Mathf.Cos(Time.realtimeSinceStartup);
        rotY[0, 2] = Mathf.Sin(Time.realtimeSinceStartup);
        rotY[1, 1] = 1;
        rotY[2, 0] = -Mathf.Sin(Time.realtimeSinceStartup);
        rotY[2, 2] = Mathf.Cos(Time.realtimeSinceStartup);
        rotY[3, 3] = 1;
        Matrix4x4 m = m4 * rotY;

        mat.SetMatrix("mvp",m);
    }
}

效果:

3.加入缩放

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class mvp : MonoBehaviour
{
    private MeshRenderer rend;
    private Material mat;
    void Start()
    {
        rend = GetComponent<MeshRenderer>();
        mat = rend.material;
    }

    // Update is called once per frame
    void Update()
    {
        Matrix4x4 m4 = Camera.main.projectionMatrix * Camera.main.worldToCameraMatrix * transform.localToWorldMatrix;

        Matrix4x4 rotY = new Matrix4x4();
        rotY[0, 0] = Mathf.Cos(Time.realtimeSinceStartup);
        rotY[0, 2] = Mathf.Sin(Time.realtimeSinceStartup);
        rotY[1, 1] = 1;
        rotY[2, 0] = -Mathf.Sin(Time.realtimeSinceStartup);
        rotY[2, 2] = Mathf.Cos(Time.realtimeSinceStartup);
        rotY[3, 3] = 1;

        Matrix4x4 s1 = new Matrix4x4();
        float sc = Mathf.Abs(Mathf.Cos(Time.realtimeSinceStartup)) * 1.5f;
        s1[0, 0] = sc;
        s1[1, 1] = sc;
        s1[2, 2] = sc;
        s1[3, 3] = 1;

        Matrix4x4 m = m4 * rotY * s1;



        mat.SetMatrix("mvp",m);
    }
}

效果: