Runtime export in webGL environment.

[Tripl3Design]

As described in the docs, the runtime export can be used to store and share dynamic, user-generated 3D content.
The provided code snippets to save a gltf or glb to a file on your system works fantastic, but is there a possibility to export to a gltf or glb from an online (webgl) environment to the (hosting) server? That would be a really cool way to generate 3D user generated content.

[atteneder]

Hi @Tripl3Design,

That's a great use-case indeed! I never tried, but my approach would be to generate a glb into a memory stream and then:

• either upload to a server to host it there
• use some Javascript to make a direct, client-side download/save as file

GameObjectExport/IGltfWritable provides Task<bool> SaveToStreamAndDispose(Stream stream) for that.

Would be great if you could give it a shot and report if you found a working solution.

Thanks

[Tripl3Design]

O yes that is really stupid.

Well I have now:
`async void GltfExport()
{
var rootLevelNodes = GameObject.FindGameObjectsWithTag("ExportMe");
var export = new GameObjectExport();
export.AddScene(rootLevelNodes);

    Stream glbExport = new MemoryStream();
    bool success = await export.SaveToStreamAndDispose(glbExport);

    Debug.Log("Export = " + glbExport);
    StartCoroutine(SaveGlb(glbExport));

    if (!success)
    {
        Debug.LogError("Something went wrong exporting a glTF");
    }
}

IEnumerator SaveGlb(Stream glbExport)
{
    var memoryStream = new MemoryStream();
    glbExport.CopyTo(memoryStream);

    byte[] byteArray = memoryStream.ToArray();
    UnityWebRequest www = UnityWebRequest.Put("https://etc...", byteArray);
    yield return www.SendWebRequest();

    if (www.result != UnityWebRequest.Result.Success)
    {
        Debug.Log("Error");
    }
    else
    {
        Debug.Log("Upload complete!");
    }
}`

And the eror in the console is:
MethodAccessException: Attempt to access method 'GLTFast.ICodeLogger.Error' on type '' failed. at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x00000] in <00000000000000000000000000000000>:0

working demo

[atteneder]

I suspect an error during export. Does it work in the Editor? Because that's way more efficient to iterate. If not, is the error message more verbose if you run a debug build?

You're not waiting for StartCoroutine(SaveGlb(glbExport)); to finish! Within an IEnumerator you could do yield return StartCoroutine(SaveGlb(glbExport));, but your GltfExport is an async void, so you'd have to wrap it.

no need to copy glbExport to memoryStream. Use glbExport right away.

[Tripl3Design]

Is it possible to test a SaveToStreamAndDispose in de Editor?
If i do this:
` async void GltfExport()
{
var rootLevelNodes = GameObject.FindGameObjectsWithTag("ExportMe");
var export = new GameObjectExport();
export.AddScene(rootLevelNodes);

    MemoryStream memoryStream = new MemoryStream();
    bool success = await export.SaveToStreamAndDispose(memoryStream);

    if (!success)
    {
        Debug.LogError("Something went wrong exporting a glTF");
    }
}`

I get a NullReferenceException: Object reference not set to an instance of an object

[atteneder]

I consider figuring out a NullReferenceException a basic skill of software development. If you're not up to that task or able to teach it yourself frankly I don't want to spend the time teaching it to you. Good luck anyways.

I might create an real-time export demo some day.

[Tripl3Design]

Yes, you are completely right. It's a noob error. Thanks for your time.
SaveToFile works perfectly.
I'm having trouble with SaveToStream. I'm probably not sending the right arguments. Because I don't quite understand that system.IO.Stream.

[Tripl3Design]

I did a bit of research, and this works for me:

`async void GltfExport()
{
var logger = new CollectingLogger();
var exportSettings = new ExportSettings
{
format = GltfFormat.Binary,
fileConflictResolution = FileConflictResolution.Overwrite
};
var export = new GameObjectExport(exportSettings, logger: logger);
var rootLevelNodes = GameObject.FindGameObjectsWithTag("ExportMe");
export.AddScene(rootLevelNodes, "My new glTF scene");

    //for local testing
    //var fileName = "model.glb";
    //var outStream = new FileStream(Path.Combine(path, fileName), FileMode.Create);
    var outStream = new MemoryStream();
    bool success = await export.SaveToStreamAndDispose(outStream);

    if (!success)
    {
        Debug.LogError("Something went wrong exporting a glTF");
        logger.LogAll();
    }

    StreamToBytes(outStream);
}

public void StreamToBytes(Stream outStream)
{
    var bytes = new byte[outStream.Length];
    outStream.Seek(0, SeekOrigin.Begin);
    outStream.ReadAsync(bytes, 0, bytes.Length);
    outStream.Dispose();

    StartCoroutine(UploadGlbPost(bytes));
}

IEnumerator UploadGlbPost(byte[] bytes)
{
    List<IMultipartFormSection> formData = new List<IMultipartFormSection>();
    formData.Add(new MultipartFormFileSection("glbfile", bytes, "tempname.glb", "model/gltf-binary"));
    UnityWebRequest www = UnityWebRequest.Post(path, formData);
    yield return www.SendWebRequest();

    if (www.result != UnityWebRequest.Result.Success)
    {
        Debug.Log(www.error);
    }
    else
    {
        Debug.Log("glb upload complete!");
    }
}`

End then use a little php:

`
$mydata = file_get_contents($_FILES["glbfile"]["tmp_name"]);
$fileName = 'ArModels/frame.glb';

$fh = fopen($fileName , 'wb');
fwrite($fh, $mydata);
fclose($fh);
`

Maybe it's possible without php? The PUT request gave a 405 error. Mybe that's a server issue?
I store my textures also on the server and grap them with UnityWebRequestTexture. Is there a way to use gltf's instead of glb's and use the online textures?

[atteneder]

Great. Glad you figured it all out!

Yes, you can load JSON based .gltf as well.

[Tripl3Design]

Well, I need a solution to add the textures (wich are already on the server) to the glb. Or gltf, but only a self-contained gltf is possible when using a stream.

This is the source (Unity webgl):

And this the exported glb without the the textures wich are on the server.

EDIT: I think the same happens when using SaveToFileAndDispose() in the Editor. The textures are not downloaded.

[atteneder]

There is support for texture export (embed in the glb), but only for certain shaders (Lit; see #385). Which ones are you using and does it work in the editor?

[Tripl3Design]

It is a standard shader. The basemap is a jpg wich is on the server (to reduce build size). It doesn't work in the editor either. Op wo 31 aug. 2022 12:54 schreef Andreas Atteneder ***@***.***

…

: There is support for texture export (embed in the glb), but only for certain shaders (Lit; see #385 <#385>). Which ones are you using and does it work in the editor? — Reply to this email directly, view it on GitHub <#455 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANMGR4IIFWNYTRUAGDMN26DV342V5ANCNFSM57K7BYOA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[atteneder]

That should work though. Please raise an issue and provide a sample asset that reproduces the error. Thanks

[PantherStudio1]

Hello, I'm using glTFast plugin 4.5.0, Unity 2020.3.20f1, I'm facing an issue saying : 'GameObjectExporter' does not contain definition for
'SaveToStreamAndDispose'.

If the 'SaveToStreamAndDispose' is removed, then in which version I would be able to use it?

Please help me with this issue as I'm working on a project where is it needed.

The 'GameObjectExport' class has only 'SaveToFileAndDispose' defined in it.

[atteneder]

@PantherStudio1 Export GLBs to a Stream was added in 4.6.0 on 2022-02-23. Please update to a newer version.

[PantherStudio1]

Thank you for a quick reply.

[Anksji]

how to solve this texture loss problem when exporting the model at run time in unity webgl.

I used this code to export the model async void ModelExport(GameObject[] models)
{

    // CollectingLogger lets you programatically go through
    // errors and warnings the export raised
    var logger = new CollectingLogger();

    // ExportSettings and GameObjectExportSettings allow you to configure the export
    // Check their respective source for details

    // ExportSettings provides generic export settings
    var exportSettings = new ExportSettings
    {
        Format = GltfFormat.Binary,
        FileConflictResolution = FileConflictResolution.Overwrite,
        // Export everything except cameras or animation
        ComponentMask = ~(ComponentType.Camera | ComponentType.Animation),
        // Boost light intensities 
        LightIntensityFactor = 100f,
    };

    // GameObjectExportSettings provides settings specific to a GameObject/Component based hierarchy
    var gameObjectExportSettings = new GameObjectExportSettings
    {
        // Include inactive GameObjects in export
        OnlyActiveInHierarchy = false,
        // Also export disabled components
        DisabledComponents = true,
        // Only export GameObjects on certain layers
        LayerMask = LayerMask.GetMask("Default", "MyCustomLayer"),
    };

    // GameObjectExport lets you create glTFs from GameObject hierarchies
    var export = new GameObjectExport(exportSettings, gameObjectExportSettings, logger: logger);

    // Example of gathering GameObjects to be exported (recursively)
    var rootLevelNodes = models;

    // Add a scene
    export.AddScene(rootLevelNodes, "My new glTF scene");


    string ProjectPath = Path.GetFullPath(Path.Combine(Application.dataPath, ".."));
    //string WebExportPath = Path.GetFullPath(Path.Combine(ProjectPath, "../../web/UnityLibrary/exports"));
    string WebExportPath = "E:\\myfolder\\model_Export";
    //System.IO.File.WriteAllText(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Desktop) + "\\App\\mytextfile.txt", "Test");

    string fileName = "NewModel_" + DateTime.Now.ToString("yyyyMMdd_HHmmss") + "_" + PublicMethods.GenerateRandomString(3) + ".glb";
    //string fileName = "Aug_model"+PublicMethods.GenerateRandomString(3)+"model"+ PublicMethods.GenerateRandomString(4)+".gltf";
    string filePath = Path.GetFullPath("E:\\myfolder\\model_Export\\" + fileName);
    //string filePath = Path.Combine(WebExportPath, fileName);
    // Async glTF export
    messageText.SetText("Export starts latest... ");
    //saving model in byte
    var outStream = new MemoryStream();
    //saving file in bytes
    //var success = await export.SaveToStreamAndDispose(outStream);
    //saving model in file
    var success = await export.SaveToFileAndDispose(filePath);

    if (!success)
    {
        messageText.SetText("Something went wrong exporting a glTF ");
        Debug.LogError("Something went wrong exporting a glTF");
        // Log all exporter messages
        logger.LogAll();
    }
    else
    {

        messageText.SetText("glTF model export success at location " + filePath);
        StreamToBytes(outStream);
        Debug.Log("glTF model export success at location " + filePath);
    }
}

[atteneder]

Though your problem might be related to one that @Tripl3Design had, I think this should be a regular bug report via an issue.
Also, you need to provide much more details about your problem.