setPerspective(fov, near, far, width, height, pixelRatio) {
        this.setPixelRatio(pixelRatio);
        this.setSize(width, height);
        this.setFov(fov);
        this.setNear(near);
        this.setFar(far);

        if(this._shouldUpdate) {
            this.updateProjectionMatrix();
        }
    }
Sets the camera perspective
     Update the camera projection matrix if our _shouldUpdate flag is true

     params:
     @fov (float, optional): field of view to use
     @near (float, optional): near plane value to use
     @far (float, optional): far plane value to use
     @width (float, optional): width value to use
     @height (float, optional): height value to use
     @pixelRatio (float, optional): pixelRatio value to use
*