无法为子游戏对象创建碰撞网格

Question

我正在创建fbx处理脚本，以更改某些网格参数，自动创建预制和添加碰撞网格。现在，我被困在添加碰撞网格组件到我的游戏对象的某些子级。但到目前为止还没找到。我收到一条错误消息" can 't add component 'MeshCollider‘to UCX_SM_bench_1_LOD0“，因为游戏对象是一个生成的预制对象，只能通过AssetPostprocessor进行修改。我使用的是Unity 2017.1。

我是一个3D艺术家，这是我第一次尝试编写脚本。

using System;
using System.IO;
using UnityEngine;
using UnityEditor;

public class ModelAssetPostprocessor : AssetPostprocessor
{
public void OnPreprocessModel()
{
    ModelImporter modelImporter = assetImporter as ModelImporter;
    modelImporter.importAnimation = false;
    modelImporter.importBlendShapes = false;
    modelImporter.importCameras = false;
    modelImporter.importVisibility = false;
    modelImporter.importLights = false;
    modelImporter.importTangents = ModelImporterTangents.Import;
}
private const string PREFAB_DESTINATION_DIRECTORY = "Assets/Prefabs/";//setting up constant for prefabs destination directory

private static void OnPostprocessAllAssets(
    string[] importedAssets,
    string[] deletedAssets,
    string[] movedAssets,
    string[] movedFromAssetPaths)           
{
    foreach (string path in importedAssets) 
    {
        if (!path.EndsWith(".fbx", StringComparison.OrdinalIgnoreCase)) //skipping all the files, which are not .fbx
            continue;

        GameObject modelAsset = AssetDatabase.LoadAssetAtPath<GameObject>(path);    //As far as I understand here we declare local variable "modelAsset"
                                                                                    //It will become GameObject, which took from AssetDatabase using path we saved before. So
                                                                                    //Now we have a GameObject. 
        CreatePrefabFromModel(path, modelAsset);
        //And now we declare a function to create prefab from our game object
    }
}

private static void CreatePrefabFromModel(string path, GameObject modelAsset)
{
    EnsureDirectoryExists(PREFAB_DESTINATION_DIRECTORY);

    string modelFileName = Path.GetFileNameWithoutExtension(path);
    string destinationPath = PREFAB_DESTINATION_DIRECTORY + modelFileName + ".prefab";

    if (!File.Exists(destinationPath))
    {
        GameObjectUtility.SetStaticEditorFlags(modelAsset, StaticEditorFlags.LightmapStatic | StaticEditorFlags.NavigationStatic | StaticEditorFlags.BatchingStatic | StaticEditorFlags.OccludeeStatic | StaticEditorFlags.OccluderStatic | StaticEditorFlags.OffMeshLinkGeneration | StaticEditorFlags.ReflectionProbeStatic);

        foreach (Transform child in modelAsset.transform)
        {
            if (child.transform.name.Contains("UCX_"))
            {
                Renderer rend;
                rend = child.GetComponent<Renderer>();
                rend.enabled = !rend.enabled;

                string childname = child.transform.name;

                      GameObject childobject = modelAsset.transform.Find(childname).gameObject;
                      childobject.AddComponent<MeshCollider>();
            }
        }
        PrefabUtility.CreatePrefab(
            destinationPath,
            modelAsset);
    }
    else
    {
        PrefabUtility.ReplacePrefab(
            modelAsset,
            AssetDatabase.LoadAssetAtPath<GameObject>(destinationPath),
            ReplacePrefabOptions.ReplaceNameBased);
    }
}
private static void EnsureDirectoryExists(string directory)
{
    if (!Directory.Exists(directory))
        Directory.CreateDirectory(directory);
}
}   

Answer 1

我不知道你想要达到什么目的，但首先，试着在模型导入(https://docs.unity3d.com/Manual/FBXImporter-Model.html)中选中Generate Colliders复选框，也许它会解决你所有的问题。

Image

第二个建议-更新unity (不，你的脚本不会工作，但有新版本总是更好的方法)

根据你最初的要求。我所能建议的是( unity 2018.3的代码)：

var go = GameObject.Instantiate(modelAsset);

GameObjectUtility.SetStaticEditorFlags(modelAsset, (StaticEditorFlags)(-1));

foreach (Transform child in go.transform)
{
    if (child.name.Contains("UCX_"))
    {
        Renderer rend;
        rend = child.GetComponent<Renderer>();
        rend.enabled = !rend.enabled;

        child.gameObject.AddComponent<MeshCollider>();
    }
}

PrefabUtility.SaveAsPrefabAsset(go, destinationPath);
GameObject.DestroyImmediate(go);

我稍微修改了一下你的脚本。现在将首先实例化网格，并从实例化的对象创建预置，而不是从资源。

出现错误的原因是:您正在尝试修改fbx文件，就像它是一个场景对象一样。你应该首先实例化它，然后做任何你想做的更改，然后将它保存为预置。