Sandbox - generated glb size much bigger than the original one

[bvaisman]

Hi everybody,

There is something that I don’t understand with the sandbox. If I load a glb file and try to save it again as a glb file without the environment( skybox, light…), the size of the resulted file is much bigger.

Do you know why ? Is there a way to change that ?

Thanks in advance,

Boris

[Evgeni_Popov]

Maybe this post can help:

GLB export changes original image

OS: Windows 10 x64 Browser: ungoogled-chromium 108.0.5359.95 Babylon.js: 5.38.0 Playground: Babylon.js Playground Expected: Exported GLB should contains the original image. Actual: JPEG-encoded image is converted to PNG. Image size goes from 8160 bytes to 112602 bytes. See the console.assert codes for detail.

[bvaisman]

Ok, I understand. Do you know is there’s still an issue about that or do you want me to post a new one ?

Thanks for your answer,

Boris

[Evgeni_Popov]

We already have some issues created for the glTF exporter:

• GLTFSerializer v2 · Issue #12600 · BabylonJS/Babylon.js · GitHub
• .glTF Export Instanced Meshes as Nodes Pointing to the Same Mesh · Issue #14056 · BabylonJS/Babylon.js · GitHub
• KTX Textures get lost on GLB Export · Issue #12257 · BabylonJS/Babylon.js · GitHub
• Implement Draco-compressed GLB export option in Sandbox' Inspector · Issue #8046 · BabylonJS/Babylon.js · GitHub

[kzhsw]

Also this if 16bit indices or KHR_mesh_quantization used in your model:

Keep index and KHR_mesh_quantization attributes on GLB export

OS: Windows 10 x64 Browser: ungoogled-chromium 108.0.5359.95 Babylon.js: 5.38.0 Playground: Babylon.js Playground Expected: Exported GLB should contains the original index and attribute buffer. Actual: index changed on export, expected: Uint16Array actual: Uint32Array index byteLength changed on export, expected: 6 actual: 12 position type changed on export, expected: 5123 actual: 5126 position size changed on export, expected: 6 actual: 12