That behavior actually changed starting in NX 8.0 as part of a rather subtle enhancement with respect to both the 'Point/Origin' portion of all Modeling dialogs as well as a change in behavior when you edit any feature which used the 'Point/Origin' function when creating the feature.
As I alluded above, the NX 8.0 enhancement had two parts, the first being that in all Modeling dialogs where there is a 'Point/Origin' option you now have the option to display a list of 'Shortcuts' for the most often used 'Point' options and this is available whether the 'Snap Points' in the Selection Bar are active or not. The second part of the enhancement is actually the really subtle part and that is that when you create any sort of feature that involved selecting a point, whether it was an explicit selection or not, that method used when creating the feature is actually saved as part of what we call the 'feature method' however most people were not aware of that even though you could edit that when the edited the feature just that there was no indication as to exactly what point method was originally used when you created the feature. That all changed starting with NX 8.0. Now when you edit the feature and the dialog for that feature opens, in the past the 'Point/Origin' option always reset to 'Inferred' despite the fact that that's meaningless since 'Inferred' is NOT actually a method used, but rather just a way to indicate that you can select anything that you want to select but it gives you NO feedback as to what was used when the feature was created. Now it does. So if you create say a Block feature where you selected the 'End Point' of curve when you edit the Block it will now show that indeed you DID use an 'End Point' because the 'Point/Origin' will show an 'End Point'. We're just providing MORE feedback about how the feature was actually created. For many people this could prove to be a very useful bit of additional information.
Now exactly how did this change what you're seeing when you create a Sketch. Well in those situations where making a selection in some other part of a dialog causes the 'Point/Origin' selection to be made automatically, while in the past even though something WAS selected there was NO indication what that Point method actually was even though you could probably guess by looking at the feedback on the screen. Now when the inference has been made the dialog is updated to show you what Point/Origin method WAS used. In the case of selecting say the face of a Block to create a Sketch, in reality, and you can clearly see this, an 'End Point' of one of the face edges was selected as the Origin which is why the 'Select Origin' switched to 'End Point'. Note that if you had selected a Datum Plane it would have switched to 'Fixed' and if you had selected the end of Cylinder it would have switched to show that the 'Arc Center' method had been used. Now I will admit that this does not provide as much additional functionality when working with Sketches since editing a Sketch does not automatically use the original dialog, unlike other features where you are given the opportunity to edit the 'Origin' and thus it would be useful to know what method was used originally.
Now before you comment on the fact that in NX 7.5, since it always defaulted to 'Inferred', that when you made the 'Point/Origin' entry active that this would also make the Snap Points in the selection bar active and so now you have to make an additional selection, back to 'Inferred', before that's the case, let me remind you that you now have the option to show at least six of the most recently used point methods in the 'Shortcut Toolbar' in the 'Point/Origin' section of the dialog so that those methods are always available irrespective of what the default method was set to. You can use these six additional icons (actually five since the current one will always to shown in the Shortcuts) to change the method used if you really wanted something other than what the Sketch function had inferred by how you had selected the Sketch plane.
BTW, this same behavior change can be seen wherever a feature which uses a Vector, including providing you with the optional Shortcuts as well as the feedback when editing a feature which used a Vector as part of its 'method'.
Anyway, I hope you can see how this subtle change is actually a rather nice enhancement when you understand what's happening and how you can leverage the additional information now shown to you, both during creation and editing, although this last aspect is not as applicable to Sketches as it is to most all the other Modeling features, but hey, it's at least consistent.
John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
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