Sandbox GLB exporter question

Hi there:

At the moment, We’re using the superb BJS Sandbox as a main tool in our work with AR apps pipeline (native and web), as we use GLTF/GLB as the standardized 3D assets format.

The case is that we’ve detected that, in certain occasions, the GLB generated by Sandbox doesn’t work in apps (don’t crash but it shows nothing in the AR layer). Using instead Cesium’s gltf-pipeline command line tool over the same GLTF generates GLB files that always work perfect with the aforementioned apps.

Said that, can anyone come up with any idea about the cause(s) for this inconsistent behavior experimented with the Sandbox exporter? Certainly We’d prefer to use Sandbox instead of the Cesium command line tool, because with Sandbox we have a very convenient bundle of tools all in one.

By the way, are you planning to include Draco compression ability in Sandbox GLB export?

Best regards.

Thanks :wink:

Adding @bghgary and @Drigax

Can you expand on this please? In what occasions do the glb files not work? is there a specific object in scene that is causing an invalid glb to be exported? can you create a minimal playground scene that can reproduce this?

We don’t have any plans for this, but it shouldn’t be hard to add. We would welcome a contribution for this.

Hi Drigax:

We’re working intensively with the pipeline BJS Sandbox - ARCore/Sceneform/Filament these days, so we’ll try to identify some kind of pattern with the specificities of the models that give problems.

I’ll be in touch.

Hi Gary:

Well, I think Draco compression is a must-have in a real-world pipeline these days, both for web and cloud-based-native apps.

Of course, at the final iterations of a project the CG-artist must deliver a properly mesh-optimized model, and then Draco will not be so useful; but in the early iterations, with still not quite worked models, Draco will help a lot in terms of downloading speed.

Best regards.

Hi Nicholas:

About the apparent problem with the exportation of some GLBs within ARCore/Sceneform/Filament developments, as stated in this issue, it could be a problem of that Google’s technology.

Best regards.

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Hi there, Gary:

Certainly, It would be very convenient to have incorporated the “draced” GLB export, in order to not be forced to use other tool, as the aforementioned gltf-pipeline.

Keep in mind that, from a practical point of view, other very useful feature to be included in Sandbox is the ability to save to GLTF. This way you can tweak parameters here and there in meshes, textures, materials, and so on; and have the option to generate a “fixed” scene, without the need to go back to the 3D authoring tool.

Best regards.

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Sure. Open a feature request on GitHub?

I’m not sure if you are asking for a feature. There is already a way to save a GLB from the sandbox using the inspector.

That said, the loading of a glTF into Babylon Sandbox and exporting it back out is inherently a lossy step. Babylon doesn’t keep all the information from a glTF when loaded since it isn’t able to represent exactly what glTF files do, so this kind of process may not be the best. glTF is intended as the last mile format.