U3d杂谈 — Mesh的合并

在研究动态生成NavMesh的时候，学习到了合并Mesh的方法。我们可以把多个静态的Mesh合成一个大的Mesh,这在优化方面也是非常有用的。下面我们简单讲解如何合并Mesh。

现在我们创建一个脚本，里面给一个列表，把要合并的Mesh对象添加进来。

public class MeshCombine : MonoBehaviour
{
    public List<GameObject> m_ReadyCombine = new List<GameObject>();
    // Start is called before the first frame update
    void Start()
    {
        MeshFilter[] list = GetAllMesh();
        Mesh msh = new Mesh();
        msh.indexFormat = UnityEngine.Rendering.IndexFormat.UInt32;
        List<CombineInstance> combineInstances = new List<CombineInstance>();
        for(int i = 0; i< list.Length;++i)
        {
            combineInstances.Add(new CombineInstance()
            {
                mesh = list[i].sharedMesh,
                transform = list[i].transform.localToWorldMatrix
            });
        }
        msh.CombineMeshes(combineInstances.ToArray());

        GameObject go = new GameObject(name);
        go.transform.position = Vector3.zero;
        go.transform.localScale = Vector3.one;
        go.transform.localRotation = Quaternion.identity;



        MeshFilter m = go.AddComponent<MeshFilter>();
        m.mesh = msh;

    }

    MeshFilter[] GetAllMesh()
    {
        List<MeshFilter> r = new List<MeshFilter>();
        for(int i = 0; i < m_ReadyCombine.Count; ++i)
        {
            MeshFilter s = m_ReadyCombine[i].GetComponent<MeshFilter>();
            if(s != null)
            {
                r.Add(s);
            }
        }
        return r.ToArray();
    }

}

Mesh有个CombineMeshes的函数，可以传入CombineInstance[]参数。这个是单个Mesh的实例。这样我们就把独立的Mesh合并为一个大的Mesh。