Glb 4 times bigger than gltf

Hi all,
When exporting from 3dsMax, glb-files are 3-4 times biger than the sum of all files exported files as gltf (ALL settings are equal between the two). How can I solve this?

Pinging @bghgary

There should be no difference between glTF and GLB in terms of reusing the textures (from a format perspective). Perhaps the code isn’t working right. As @kvasss says, please share a repro.

First, I am using the Babylon 3ds Max exporter from Babylon website.

The result is the same for any 3ds max model with a few textures - glb exports 4-5 times bigger than the sum of all exported gltf-files including textures. It might be the glb-export converts jpegs to png? The “try reuse texture” has no effect.

If you can share a simple repro, that will save us some time. Thanks!

@Guillaume_Pelletier Can you investigate once we have a repro?

yes, sure.

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glb vs gltf size

@bghgary @Guillaume_Pelletier - Thanks!!
For some reason, new users can´t upload attachments here. Anyway, I did a simple teapot in Max, applied a “Physical material” , plugged textures into four slots, then ran the exporter as seen above. As you can see in this simple test, glb is 3 times bigger than the sum of files using gltf-export.
3ds max material

Ok i reproduce the behavior. Its seems the jpg which is embedded into the glb is in cause (tripple the size than the one saved for gltf).

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@Guillaume_Pelletier thanks, is it the albedo or the ORM or both?

In your case, this is about ORM (indeed any reconstructed bitmap), wich was for any historical reason save at raw data inside glb buffer (no compression at all). This was not visible for png, only for jpg. I made a fix which is make the glb smaller than the sum of gltf file, but due to the fact it affect every reconstructed Image bitmap, we may reconduct a full serie of test which can take some time before publishing the fix. I let the core Babylon team decide, because i maybe miss something.

Great! The texture quality setting is essential when the ORM is created as this have a significant impact when balancing final quality vs size.
When running the gltf-files through something like Make glb the glb equals the sum og gltf-files.