public Camera(Vec3 origin, Vec3 lookAt, Vec3 up, int width, int height, float verticalFov)
{
this.width = new SpecializedValue <int>(width);
this.height = new SpecializedValue <int>(height);
this.verticalFov = verticalFov;
this.origin = origin;
this.lookAt = lookAt;
this.up = up;
axis = OrthoNormalBasis.fromZY(Vec3.unitVector(lookAt - origin), up);
aspectRatio = ((float)width / (float)height);
cameraPlaneDist = 1.0f / XMath.Tan(verticalFov * XMath.PI / 360.0f);
reciprocalHeight = 1.0f / height;
reciprocalWidth = 1.0f / width;
}