After using gltf-transform to compress the model, do we have to do this?

Questions
1

I used the gltf-transform plugin to optimize the model, and the command was:

gltf-transform optimize car.glb car_1.glb --compress meshopt --texture-compress webp --texture-size 512

It works fine on a computer, but when embedded in ios as a webview, it gets an error.
the error: “error:https://cdn.babylonjs.com/meshopt_decoder.js”

I learned that with the meshopt algorithm, bjs has to load the plugin, so I added this code！！！

 const engine = new Engine(canvas, antialias, engineOptons, adaptToDeviceRatio);

    MeshoptCompression.Configuration = {
      decoder: {
        //  default is the CDN path, I changed it and  use my local files
        url: "javascripts/meshopt_decoder.js"  // the path of my local file
      }
    };
    const scene = new Scene(engine, sceneOptions);

There don’t seem to be too many examples of meshopt, should I do this?
Or is there a better compression than meshopt to optimize the model on the mobile ?

thank you.！！！

2

This should work, not sure why it would not change the url.

cc @RaananW and @bghgary

3

This sounds like a WebView problem. I don’t have much experience with using WebView on iOS, but from a quick look at documentation, it really depends on how you loaded the page. For example, if call loadHTMLString, there is a baseURL parameter that determines where the local files are loaded from. If you call loadFileURL, there is an allowingReadAccessTo parameter. How are you loading your WebView?

4

But I’m sure that if I didn’t optimize the model with gltf-transform, there would be no errors on ios

5

Right, optimizing with meshopt requires the loader to load the meshopt extension which must load the meshopt library from separate js/wasm files. If you don’t optimize with meshopt or draco then you don’t need the separate files.

6

After testing and comparison, we found that the optimization result of meshopt is very good. Of course, I do not want to load additional plugins, because I think loading plugins on the mobile terminal will always affect the performance or loading speed. Is there any other better optimization scheme?

7

And I also learned that android loading external files seems to be not allowed, like this loading external js files, will there be a problem.

8

From your message I can’t seem to understand if it worked once you used the local file instead of the CDN. Does it work locally? (And sorry if I missed something!)

9

It depends on what you are doing with the model. A lot of times, simply doing quantization makes a big difference. Quantization does not require additional libraries. Meshopt or Draco will compress more but it may not give a huge difference.

1 Like
10

Yes, there is an error when using the CDN in the app

11

So it does work locally - a perfect solution TBH.

would be very interesting to understand why the CDN file didn’t work. I believe @bghgary discussed that in his first answer.