3D model apear flat not showing shades

[Jorge_Luis_Lemus_Ram]

Hi, thanks in advance for the your time.

I uploaded a “.glb” model to cesium.
This is how the model should have been rendered:

And this is how cesium is rendering it

basically, it does’nt render shades and the model looks flat

I’m using SahrpGltf to generate the model from some topographic data.
In my code i’m using MetallicRoughnessShader.

hope you can help me, thanks in advance

[Marco13]

(@Monica I think this question was asked in two categories, but was now already answered in 3D model does not display shades )