We have successfully converted OBJ models to COLLADA and then GLTF. The models and textures are appearing correctly. However, depending on the angle from the camera to the model there is shading being applied that makes parts of the model very dark.
In other software we have been able to modify the luminosity to override this shading effect and still see the texture, but we have not found any way to eliminate the shading in Cesium.
We have turned off the lighting on the globe and made adjustments to every material parameter (ambient, diffuse, specular, emissions, shininess) without the desired result.
Is there a way to eliminate this shading effect (while retaining the image texture)?