> Trackballs are supposed to emulate a trackball mouse which don't have this limitation.
Some systems implement a trackball UI that behaves like a real trackball, i.e. it also has inertia, so you can give an impulse towards a direction and the 3D model will continue to rotate after you no longer click the mouse button, until you stop the rotation.
I do not remember using any trackball UI where the rotation was limited. When the trackball UI did not have inertia, than you would need to do 3 pushes for a rotation over 360 degrees or 2 pushes for a rotation over 180 degrees, but you could still reach any angles.
Some systems implement a trackball UI that behaves like a real trackball, i.e. it also has inertia, so you can give an impulse towards a direction and the 3D model will continue to rotate after you no longer click the mouse button, until you stop the rotation.
I do not remember using any trackball UI where the rotation was limited. When the trackball UI did not have inertia, than you would need to do 3 pushes for a rotation over 360 degrees or 2 pushes for a rotation over 180 degrees, but you could still reach any angles.