Why light are not equally reflect on the object

i am trying HemisphericLight but some part of object seen dark and some part seen mush brighter

this.light = new HemisphericLight(“light”, new Vector3(0, -1, 0), scene);
if(this.modalpaperInfo.lightIntensity === undefined){
this.light.intensity = 0.7;
} else{
this.light.intensity = this.modalpaperInfo.lightIntensity ;

I’m not sure what you are trying to point out with the red circled areas. The two areas are of similar color and brightness. What are you expecting to see?

I expect this to be a problem if you haven’t set up shadows.

check your model normal face