Unity performance optimization

One 、 Optimization premise

1,unity Installation package , Operation card

      Built in mono virtual machine

     C# stay mono Running on a virtual machine ,mono Virtual machines are cross platform

2,DrallCall   Draw calls , performance GPU,CPU, and GPU Rendering related

     CPU The call of graphic drawing interface ,CPU Through the graphics library interface , command GPU Rendering

     DrallCall The bigger it is , The more performance consumption , Cause game running card

     CPU processor , Equivalent to our brains , Perform logical processing calculation

     GPU Specially for game drawing , Scene character model , A lot of preparation will be done before each drawing

      Reduce CPU Yes DrallCall Call to ,drallcall many ,CPU Be prepared for extra expenses

3,Profiler Viewing performance , stay Window In form

4, Statistics panel ,game Mode of stats

    FPS frame per second , The larger the number of frames, the smoother , exceed 30 Frame the human eye can't feel the card

     CPU, Time consumed per frame , One second is equal to 1000 millisecond

     render  thread   Rendering is determined by the graphics card

     Batches： The batch ,

     Verts： Number of vertices in camera field

     Tris   ： The number of triangles in the camera's field of view

     setpasscall：Shader There will be many Pass,GPU Running pass Before , Will produce a SetPass

Two 、 resource optimization

1, Resource optimization criteria

       mesh   The number of patches of the dynamic model <3000,  texture of material <3, Number of bones <50,

                    Static model ： Number of vertices <500

                    Long time music （ The background music ） Compressed format mp3

                    Short music   ( Sound effect )   Uncompressed format wav, No compression , Repeats, , decompression

                   

                  Short music tick first , Long music tick the second

     Texture     The length and width of the map are less than 1024

     shader     Reduce complex operations , Reduce discard operation

2, Model optimization , Reduce the number of faces , Map optimization （ Map merging ）

3, Reduce redundant and duplicate resources

     A : Resource Resources in the directory, whether referenced or not , Will be packaged into the installation package

          Don't put unused resources in Resource Under the table of contents

     B : The same resource files in different directories , If they are all quoted , Will get into the bag

          Guarantee the same Resource files are stored in only one directory location in the project  

4, Detection and analysis of resources

UWA Tools , Optimize the size of the installation package , Optimize the performance of the installation package

3、 ... and 、GPU Optimize

      Scene rendering , Light treatment , Rendering of model character scene

    1, Level detail LOD Optimize , The closer you see, the finer , LOPGroup Components

         

    2, Occlusion culling occlusionculling, Specific operation sikiA Plan optimized video 10 Class hour

            

3、 The light map , To be specific, see siki Optimize 11 Class hour

    When there are many light sources , Calculate the points projected by multiple light sources in advance , Use map

    Select all game objects

      

4、Mesh Merge

    Combine several models into one model , Combine several scenes into a large model , Put the model into the scene

  void MeshCombine()
    {
        MeshFilter[] filters = GetComponentsInChildren<MeshFilter>();

        // A specially merged class 
        CombineInstance[] combiners = new CombineInstance[filters.Length];

        for(int i = 0; i < filters.Length; i++)
        {
            combiners[i].mesh = filters[i].sharedMesh;
            // Change coordinates 
            combiners[i].transform = filters[i].transform.localToWorldMatrix;
        }

        // After the merger mesh
        Mesh finalMesh = new Mesh();
        // Merge 
        finalMesh.CombineMeshes(combiners);

        GetComponent<MeshFilter>().sharedMesh = finalMesh;
    }

Four 、CPU Optimize

     1, Numerical operation , damage , random number , The enemy AI, Dealing with logic

        If there are many small objects in the game , Try to combine these small objects into one mesh, It also reduces the number of materials

        Multiple small objects CUP I will prepare many times

        Use fewer materials , Combine multiple maps into a large map

        When merging objects , These objects need to use the same material to have an effect

        Merge complete mesh, If the number of materials used does not decrease , It's no use ,mesh And maps should be merged

      2, Object pool , You need to create a pool of destroyed objects frequently

        Reduce instantiation , The process of destruction , Disable it when not in use ;

       // Bullet resource pool

public class BulletPool : MonoBehaviour {

    public int poolCount = 30;
    public GameObject bulletPrefab;
    private List<GameObject> bulletList = new List<GameObject>();
    private void Start()
    {
        InitPool();
    }
    void InitPool()
    {
        for(int i = 0; i < poolCount; i++)
        {
            GameObject go = GameObject.Instantiate(bulletPrefab);
            bulletList.Add(go);
            go.SetActive(false);
            go.transform.parent = this.transform;
        }
    }

    public GameObject GetBullet()
    {
        foreach(GameObject go in bulletList)
        {
            if (go.activeInHierarchy == false)
            {
                go.SetActive(true);
                return go;
            }
        }
        return null;
    }
}

     // The firing of a bullet

public class Shoot : MonoBehaviour {

    public GameObject bulletPrefab;
    private BulletPool bulletPool;

	// Use this for initialization
	void Start () {
        bulletPool = GetComponent<BulletPool>();
	}
	
	// Update is called once per frame
	void Update () {
        if (Input.GetMouseButtonDown(0))
        {
            //GameObject go = GameObject.Instantiate(bulletPrefab,transform.position,transform.rotation);
            GameObject go = bulletPool.GetBullet();
            go.transform.position = transform.position;
            go.GetComponent<Rigidbody>().velocity = transform.forward * 50;
            //Destroy(go, 3);  
            StartCoroutine(DestroyBullet(go));
        }
	}
    IEnumerator DestroyBullet(GameObject go)
    {
        yield return new WaitForSeconds(3);
        go.SetActive(false);
    }
}

      3, Optimize compilation performance , Improve compilation speed

            Put the code of the framework class that does not need to be changed frequently Plugins Under the folder ,

            as long as Plugins If the code under does not change, it will not be recompiled firstPass.dll

            After changing the code, it will only compile Editor and Plugin Code outside