Is it possible, that there is a logical error in this part of the shader? That it maybe doesn’t calculate the right viewing direction if the camera and the object is offset?
vec3 viewDirectionW = normalize(cameraPosition - vPositionW);
When I set it to vec3 viewDirectionW = vec3(0, 0, 1); the shader is also just fixed. Maybe this calculation is not adapting to the cameras perspective?
Maybe one needs to pass modelViewMatrix to the shader because of the offset?