Q:

Sprite3D changing shape abruptly

Lately I was working with Spirte3D and Box2D. I have a sphere that can be moved in any direction using device's accelerometer values, much like a Labyrinth Game. 
Whats going above my head is abrupt behaviour of 3D sphere changing shape when moving to the device edges. When the sphere is in centre its fine but as soon as it moves to the edges it changes the shape and becomes an oval sphere.
I have attached screenshots to exactly show the behaviour.
Correct shape on sphere when placed in the middle

Wrong shape of sphere when placed along the edges

Wrong shape of sphere when placed along the edges

I think the issue is with the Directional Light that I have placed above the scene (where main camera is), here is the code for same : 
DirectionLight *directionLight = DirectionLight::create(Vec3(0,0,-1), Color3B::WHITE);

Or the issue could be with the main camera. 
Thanks in advance.

A:

Orthographic projection solved the issue :)

