I’m just getting started with KHR_materials_transmission in gltf files and I’m not sure if this is a bug or user error in the way that I load the environment. Reflection and overall lighting are correctly coming from the .env, but not transmission and refraction.
Here’s the playground link: Babylon.js Playground
The transmission and refraction of the glass is showing the default blue environment when it should be showing the environment loaded from the .env file.
It works correctly when loading the model and .env in the sandbox:
To answer my own question, it was user error due to scaling. I authored my objects to be 1 unit = 1m, but it appears that Babylon loads them as 1 unit = 1cm. Scaling everything up by 100x solves the issues. I figured this out because I had the same problem with shadows not being generated at that small of a scale.
Just to correct it might have been a precision issue with cm being viewed and regarding default camera setup as Babylon do not precise anything regarding units except when loading GLTFs where is is specified that 1 unit is one meter.