I am currently trying to display a 3D room using Three.JS. I bought the model on SketchFab and I am using its GLTF format.
This model includes "baked-in" shadows using an occlusion map and a specular glossiness map. I do not plan on having dynamic cast shadows so those baked shadows are just fine.
The model is properly imported using the GLTFLoader but my issue arise when I try to light my scene. I set up a basic HemisphereLight and for some reason all my shadows and lit areas are inversed as you can see in the screenshot below:
All the areas that are supposed to be shadows are lit and all the areas that are supposed to be lit are shadows.
I've been trying to solve this for a while now and have no idea where this behaviour is coming from. I also tried to use online GLTF viewer to see if there was any problem with the model itself but everything looks fine:
