AssetPostprocessor lets you hook into the import pipeline and run scripts prior or after importing assets.
During model import the functions are called in the the following order:
OnPreprocessModel is called at the very beginning and you can override ModelImporter settings that are used for the whole model import process.
After Meshes and Materials are imported, the GameObjects hierarchy is created from the imported nodes. Use OnPostprocessMeshHierarchy to change the hierarchy. Every GameObject that represents an imported node is given a corresponding MeshFilter, MeshRenderer, and MeshCollider component. Before assigning a Material to the MeshRenderer, the OnAssignMaterialModel function is invoked.
After GameObject has initialized MeshRenderers and "userdata" exists OnPostprocessGameObjectWithUserProperties is called. That happens before children GameObjects are generated.
If animation generation was not disabled at previous stages (see ModelImporter.generateAnimations), then SkinnedMesh and Animations are generated. If possible Avatar is also created and GameObjecs hierarchy is optimized. After that OnPostprocessModel is called for the root GameObject.
OnPreprocessSpeedTree and OnPostprocessSpeedTree are called on SpeedTree assets (.spm file) the same way as OnPreprocessModel and OnPostprocessModel, except that the assetImporter type is SpeedTreeImporter.
In a production pipeline AssetPostprocessors should always be placed in pre-built dll's in the project instead of in scripts.
AssetPostprocessors change the output of imported assets, thus a compile error in one of the scripts will lead to assets being imported differently.
This can be a severe issue when working in a production pipeline. By using dll's for AssetPostprocessors you ensure that they can always be executed even if the scripts have compile errors.
This way you can override default values in the import settings or modify the imported data like textures or meshes.
| assetImporter | Reference to the asset importer. |
| assetPath | The path name of the asset being imported. |
| context | The import context. |
| GetPostprocessOrder | Override the order in which importers are processed. |
| GetVersion | Returns the version of the asset postprocessor. |
| LogError | Logs an import error message to the console. |
| LogWarning | Logs an import warning to the console. |
| OnAssignMaterialModel | Feeds a source material. |
| OnPostprocessAllAssets | This is called after importing of any number of assets is complete (when the Assets progress bar has reached the end). |
| OnPostprocessAnimation | This function is called when an AnimationClip has finished importing. |
| OnPostprocessAssetbundleNameChanged | Handler called when asset is assigned to a different asset bundle. |
| OnPostprocessAudio | Add this function to a subclass to get a notification when an audio clip has completed importing. |
| OnPostprocessCubemap | Add this function to a subclass to get a notification just before a cubemap texture has completed importing. |
| OnPostprocessGameObjectWithAnimatedUserProperties | This function is called when the animation curves for a custom property are finished importing. |
| OnPostprocessGameObjectWithUserProperties | Gets called for each GameObject that had at least one user property attached to it in the imported file. |
| OnPostprocessMaterial | Add this function to a subclass to get a notification when a Material asset has completed importing. |
| OnPostprocessMeshHierarchy | This function is called when a new transform hierarchy has finished importing. |
| OnPostprocessModel | Add this function to a subclass to get a notification when a model has completed importing. |
| OnPostprocessPrefab | Gets a notification when a Prefab completes importing. |
| OnPostprocessSpeedTree | Add this function to a subclass to get a notification when a SpeedTree asset has completed importing. |
| OnPostprocessSprites | Add this function to a subclass to get a notification when an texture of sprite(s) has completed importing. |
| OnPostprocessTexture | Add this function to a subclass to get a notification when a texture2D has completed importing just before Unity compresses it. |
| OnPostprocessTexture2DArray | Add this function to a subclass to get a notification when a texture2DArray has completed importing just before Unity compresses it. |
| OnPostprocessTexture3D | Add this function to a subclass to get a notification when a texture3D has completed importing just before Unity compresses it. |
| OnPreprocessAnimation | Add this function to a subclass to get a notification just before animation from a model (.fbx, .mb file etc.) is imported. |
| OnPreprocessAsset | Add this function to a subclass to get a notification just before any Asset is imported. |
| OnPreprocessAudio | Add this function to a subclass to get a notification just before an audio clip is being imported. |
| OnPreprocessCameraDescription | Add this function to a subclass to recieve a notification when a camera is imported from a Model Importer. |
| OnPreprocessLightDescription | Add this function to a subclass to recieve a notification when a light is imported from a Model Importer. |
| OnPreprocessMaterialDescription | Add this function to a subclass to recieve a notification when a material is imported from a Model Importer. |
| OnPreprocessModel | Add this function to a subclass to get a notification just before a model (.fbx, .mb file etc.) is imported. |
| OnPreprocessSpeedTree | Add this function to a subclass to get a notification just before a SpeedTree asset (.spm file) is imported. |
| OnPreprocessTexture | Add this function to a subclass to get a notification just before the texture importer is run. |