Hi Rudl, here's a quick example of a situation where it is more convenient to define the orientation by placing the origin point with the z-axis perpendicular to the object:



So notice there how easily the cplane is set perpendicular to that curve in that situation - it gets placed in a good location with just the first origin pick and then you can right-click to accept the default orientation and you're done. Placing it perpendicular to a surface works in the same kind of way, it gets aligned to the surface normal with the first pick.

These kinds of situations where you're mostly concerned about how the z axis of the cplane is positioned are pretty clumsy and awkward to do with the "3 points" method where you have to focus on placing the x and y axis locations and having the z axis that you are primarily concerned about only get set as a kind of side effect of those other picks.

But in other kinds of situations it can be good to do the 3 points method as well - so that's supported in MoI as well by turning off that "Align to objects" checkbox. Then the process becomes - place the origin point, drag the x axis to the second point, and drag the y axis to the third point, so that's how the orientation picker supports that kind of 3 point operation as well.

Having these different methods available helps to make the orientation picker flexible and able to work in a couple of different ways.

- Michael