A constraint makes your ortho camera properly work with objects parented to it, so that they don’t move when the user zooms the camera.
Constraints are used to set up various relations between objects by
affecting their position, rotation and scale. Can be used with the
Object3D.constraints property.
Used to check whether this or derived classes are fix ortho zoom constraints. Default is true.
The constraint's type. Equals to "FixOrthoZoomConstraint".