Unity editor extension to create a list of meshes on a Scene and sort them by number of vertices or triangles

MeshInfoWindow.cs

using System.Linq;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

public class MeshInfoWindow : EditorWindow
{
    private enum TableSortState
    {
        None,
        VertexCount,
        TriangleCount,
        ObjectCount,
        TotalTriangleCount
    }

    private List<MeshInfo> meshInfos = new List<MeshInfo>();
    private Vector2 scrollPosition;
    private TableSortState sortState = TableSortState.None;

    [MenuItem("Window/Mesh Info")]
    static void Init()
    {
        var window = GetWindow<MeshInfoWindow>();
        window.Show();
    }

    void OnGUI()
    {
        if (GUILayout.Button("Initialize", GUILayout.Height(30)))
        {
            Initialize();
        }

        EditorGUILayout.BeginHorizontal();

        GUILayout.FlexibleSpace();
        GUILayout.Label("Sort By:");

        if (GUILayout.Button("Vertex Count"))
        {
            SortBy(TableSortState.VertexCount);
        }

        if (GUILayout.Button("Triangle Count"))
        {
            SortBy(TableSortState.TriangleCount);
        }

        if (GUILayout.Button("Object Count"))
        {
            SortBy(TableSortState.ObjectCount);
        }

        if (GUILayout.Button("Total Triangle Count"))
        {
            SortBy(TableSortState.TotalTriangleCount);
        }

        EditorGUILayout.EndHorizontal();

        GUILayout.Space(10);

        EditorGUILayout.BeginHorizontal();
        GUILayout.Label("Mesh Name", GUILayout.Width(200));
        GUILayout.Label("Vertex Count", GUILayout.Width(100));
        GUILayout.Label("Triangle Count", GUILayout.Width(100));
        GUILayout.Label("Object Count", GUILayout.Width(100));
        GUILayout.Label("Total Triangle Count", GUILayout.Width(150));
        EditorGUILayout.EndHorizontal();

        scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition);
        foreach (var entry in meshInfos)
        {
            EditorGUILayout.BeginHorizontal();

            if (GUILayout.Button(entry.MeshName, GUILayout.Width(200)))
            {
                Selection.objects = entry.MeshObjects.ToArray();
            }

            GUILayout.Label(entry.VertexCount.ToString(), GUILayout.Width(100));
            GUILayout.Label(entry.TriangleCount.ToString(), GUILayout.Width(100));
            GUILayout.Label(entry.ObjectCount.ToString(), GUILayout.Width(100));
            GUILayout.Label(entry.TotalTriangleCount.ToString(), GUILayout.Width(150));

            EditorGUILayout.EndHorizontal();
        }
        EditorGUILayout.EndScrollView();
    }

    void Initialize()
    {
        meshInfos.Clear();
        sortState = TableSortState.None;

        // Scene上の全てのメッシュを取得
        var meshFilters = FindObjectsOfType<MeshFilter>();

        var meshObjectDictionary = new Dictionary<Mesh, List<GameObject>>();
        foreach (var meshFilter in meshFilters)
        {
            if (meshFilter.sharedMesh != null)
            {
                if (!meshObjectDictionary.ContainsKey(meshFilter.sharedMesh))
                {
                    meshObjectDictionary.Add(meshFilter.sharedMesh, new List<GameObject>());
                }
                meshObjectDictionary[meshFilter.sharedMesh].Add(meshFilter.gameObject);
            }
        }

        foreach (var entry in meshObjectDictionary)
        {
            int vertexCount = entry.Key.vertices.Length;
            int triangleCount = entry.Key.triangles.Length / 3;
            int objectCount = entry.Value.Count;
            int totalTriangleCount = triangleCount * objectCount;

            meshInfos.Add(new MeshInfo(entry.Key.name, vertexCount, triangleCount, objectCount, totalTriangleCount, entry.Value));
        }

        SortBy(TableSortState.TotalTriangleCount);
    }

    void SortBy(TableSortState newState)
    {
        if (sortState == newState)
        {
            meshInfos.Reverse();
        }
        else
        {
            meshInfos = SortMeshInfos(meshInfos, newState);
            sortState = newState;
        }
    }

    List<MeshInfo> SortMeshInfos(List<MeshInfo> infos, TableSortState state)
    {
        switch (state)
        {
            case TableSortState.VertexCount:
                return infos.OrderByDescending(info => info.VertexCount).ToList();
            case TableSortState.TriangleCount:
                return infos.OrderByDescending(info => info.TriangleCount).ToList();
            case TableSortState.ObjectCount:
                return infos.OrderByDescending(info => info.ObjectCount).ToList();
            case TableSortState.TotalTriangleCount:
                return infos.OrderByDescending(info => info.TotalTriangleCount).ToList();
            default:
                return infos;
        }
    }

    private class MeshInfo
    {
        public string MeshName { get; private set; }
        public int VertexCount { get; private set; }
        public int TriangleCount { get; private set; }
        public int ObjectCount { get; private set; }
        public int TotalTriangleCount { get; private set; }
        public List<GameObject> MeshObjects { get; private set; }

        public MeshInfo(string meshName, int vertexCount, int triangleCount, int objectCount, int totalTriangleCount, List<GameObject> meshObjects)
        {
            MeshName = meshName;
            VertexCount = vertexCount;
            TriangleCount = triangleCount;
            ObjectCount = objectCount;
            TotalTriangleCount = totalTriangleCount;
            MeshObjects = meshObjects;
        }
    }
}